RESEARCH CENTRE

Inria Centre
at the University of Bordeaux

2023
ACTIVITY REPORT

IN PARTNERSHIP WITH:

CNRS, Université de Pau et des Pays de
l’Adour

Project-Team

CAGIRE

Computational AGility for internal flows
sImulations and compaRisons with
Experiments

IN COLLABORATION WITH: Laboratoire de mathématiques et de leurs
applications (LMAP)

DOMAIN

Applied Mathematics, Computation and
Simulation

THEME

Numerical schemes and simulations

Contents

Project-Team CAGIRE

1 Team members, visitors, external collaborators

2 Overall objectives

3 Research program

3.1 Turbulence modelling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.2 High-order numerical methods and efficient algorithms . . . . . . . . . . . . . . . . . . . . .
3.3 Compressible and multiphase flows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . .
3.4 Analysis and simulation of turbulent flows and heat transfer

4 Application domains
4.1 Aeronautics
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.2 Energy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.3 Automotive propulsion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.4 Medical applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5 Social and environmental responsibility

6 Highlights of the year

1

2

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3
3
4
5
6

6
6
7
7
8

9

9

7 New software, platforms, open data

10
7.1 New software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
7.1.1 AeroSol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
7.1.2 DM2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
7.1.3 UHAINA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
7.1.4 ECOGEN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
7.2 Open data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

8 New results

13
8.1 Turbulence modelling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
. . . . . . . . . . . . . . . . . . . . . . . . . 13
8.1.1 Improvement of the EB-RSM RANS model
8.1.2 Extension of RANS turbulence models to mixed and natural convection . . . . . . . 13
8.1.3 HTLES: an original hybrid RANS/LES model . . . . . . . . . . . . . . . . . . . . . . . . 14
8.1.4 Towards embedded LES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
8.1.5 Turbulent premixed combustion in the flamelet regime: developing a closure model

for the time filtered reaction rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
8.2 High-order numerical methods and efficient algorithms . . . . . . . . . . . . . . . . . . . . . 15
8.2.1 Efficient implementation of flux-reconstruction methods for combustion . . . . . . 15
8.2.2 Development of high order numerical schemes for axisymmetric turbulent flows . . 16
8.3 Compressible and multiphase flows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
8.3.1 Low-Mach-number schemes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
8.3.2 Multi-scale multiphase flows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
8.3.3 Shock-induced cavitation within a droplet . . . . . . . . . . . . . . . . . . . . . . . . . 17
8.3.4 Modelling of visco-elastic solids in multiphase flows . . . . . . . . . . . . . . . . . . . 17
. . . . . . . . . . . . . . . . . . 18
8.4.1 Effusion cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
8.4.2 Thermocline energy storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

8.4 Analysis and simulation of turbulent flows and heat transfer

9 Bilateral contracts and grants with industry

19
9.1 Bilateral contracts with industry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
9.2 Bilateral grants with industry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

10 Partnerships and cooperations

10.1 International research visitors

19
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
10.1.1 Visits of international scientists . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
10.2 National initiatives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
10.2.1 ANR MONACO_2025 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
10.2.2 ANR LAGOON . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
10.2.3 ASTURIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
10.3 Regional initiatives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
10.3.1 CELTIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

11 Dissemination

22
11.1 Promoting scientific activities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
11.1.1 Scientific events: organisation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
11.1.2 Journals
11.1.3 Invited talks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
11.1.4 Leadership within the scientific community . . . . . . . . . . . . . . . . . . . . . . . . 23
11.1.5 Research administration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
11.2 Teaching - Supervision - Juries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
11.2.1 Teaching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
11.2.2 Supervision . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
11.2.3 Juries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
11.3 Popularization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
11.3.1 Education . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
11.3.2 Interventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

12 Scientific production

26
12.1 Major publications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
12.2 Publications of the year
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
12.3 Other . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
12.4 Cited publications

Project CAGIRE

1

Project-Team CAGIRE

Creation of the Project-Team: 2016 May 01

Keywords

Computer sciences and digital sciences

A6.1.1. – Continuous Modeling (PDE, ODE)

A6.2.1. – Numerical analysis of PDE and ODE

A6.2.7. – High performance computing

A6.5.2. – Fluid mechanics

Other research topics and application domains

B2. – Health

B4. – Energy

B4.2. – Nuclear Energy Production

B5.2.1. – Road vehicles

B5.2.3. – Aviation

B5.2.4. – Aerospace

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Inria Annual Report 2023

1 Team members, visitors, external collaborators

Research Scientists

• Rémi Manceau [Team leader, CNRS, Senior Researcher, HDR]

• Pascal Bruel [CNRS, Researcher, HDR]

• Vincent Perrier [INRIA, Researcher, HDR]

• Kevin Schmidmayer [INRIA, ISFP]

Faculty Member

• Jonathan Jung [LMAP, Associate Professor]

Post-Doctoral Fellows

• Puneeth Bikkanahally Muni Reddy [UPPA, Post-Doctoral Fellow]

• Martin David [UPPA, Post-Doctoral Fellow, from Nov 2023]

PhD Students

• Anthony Bosco [UPPA]

• Esteban Coiffier [CEA]

• Alexis Ferre [CEA]

• Ibtissem Lannabi [LMAP]

• Jules Mazaleyrat [Safran HE, from Oct 2023]

• Mahitosh Mehta [UPPA, HDR]

• Corina Sanz Souhait [EDF, from Dec 2023]

• Romaric Simo Tamou [IFPEN]

Technical Staff

• Abderrahman Benkhalifa [UPPA, Engineer, from Oct 2023]

• Luca Cirrottola [INRIA, Engineer, from Feb 2023]

Administrative Assistant

• Fabienne Cuyollaa [INRIA, from Aug 2023]

2 Overall objectives

The project-team CAGIRE is an interdisciplinary project, which brings together researchers with dif-
ferent backgrounds (applied mathematics and fluid mechanics), who elaborated a common vision of
what should be the numerical simulation tools in fluid dynamics of tomorrow. The targeted fields of
application are mainly those corresponding to the aeronautical/terrestrial transportation and energy
production sectors, with particular attention paid to the issue of energy transition and the reduction of
environmental impacts. This panel has been extended to medical applications recently, where numerical
simulation plays an increasingly important role. Through our numerous industrial collaborations, we

Project CAGIRE

3

have been able to refine our vision of the future of numerical simulation, which is subject to ambitious
industrial objectives, constant evolution of computing resources and increasingly present environmental
constraints.

The flows under consideration involve many physical phenomena: they can be turbulent, compress-
ible, multiphase, anisothermal. Even if these phenomena are not necessarily present at the same time,
our strategy for developing models and numerical schemes must take them into account. Turbulence
plays a central role insofar as it is a dimensioning constraint for CFD in most industrial configurations. It
is indeed the comparison of the requirements in terms of scale of description, numerical accuracy and
computational cost that guides the choice of physical models and numerical methods.

Because such flows are exhibiting a multiplicity of length and time scales resulting from complex
interactions, their simulation is extremely challenging. Even though various simulation approaches are
available and have significantly improved over time, none of them does satisfy all the needs encountered
in industrial and environmental configurations. We consider that different methods will be useful in
the future in different situations, or regions of the flow if combined in the same simulation, in order
to benefit from their respective advantages wherever relevant, while mutually compensating for their
limitations. For instance, for turbulent flows, it will thus lead to a description of turbulence at widely
varying scales in the computational domain. The RANS1 method may cover regions where turbulence is
sufficiently close to equilibrium, leaving to LES2 the regions where the RANS description is insufficient,
leadind to a hybrid RANS-LES approach. Similarly, for two-phase flows, one of the greatest challenges
is to be able to tackle simultaneous and dynamical modelling of the multi-scale features and their
transition, e.g., from cavitation pockets to tiny bubbles. The models and numerical methods must also be
flexible enough to accurately represent all the above-mentioned phenomena in complex geometries, with
efficient and robust resolution algorithms to preserve an optimal computational cost. It is this flexibility
and adaptability of models and numerical methods that we call “computational agility", which is in the
title of the CAGIRE team: Computational AGility for internal flow sImulations and compaRisons with
Experiments.

Therefore, the long-term objective of this project is to develop, validate, promote and transfer original
and effective approaches for modeling and simulating generic flows representative of configurations
encountered in applications, in various fields, such as of transportation, energy production and medicine.
In order to progress in this direction, many building blocks have to be assembled, which motivates a
variety of research topics described in the following sections and divided into four main research axes.
The topics addressed, ranging from advanced physical modelling to high-order numerical discretization,
require the multi-disciplinary skills that constitute the CAGIRE project-team:

• Turbulence modelling

• High-order numerical methods and efficient algorithms

• Compressible and multiphase flows

• Analysis and simulation of turbulent flows and heat transfer

3 Research program

3.1 Turbulence modelling

In the “agile" simulation methods introduced above, a flexible representation of turbulence is essential:
in the same simulation, depending on the regions of the flow, it is necessary to be able to switch from
a fine-grained to a coarse-grained representation of turbulence. Numerous methods, called hybrid
RANS/LES, go in this direction, by associating LES and RANS. In order to ensure such a flexibility, it is
preferable not to rely on a preliminary partition of the domain (the so-called zonal approach), but rather
on a continuous transition from one model to the other (the so-called continuous approach).

Various questions then arise: how can we improve the RANS models so as to accurately represent
most of the physical phenomena in order to avoid having to switch to LES in large regions; how to play

1Reynolds-Averaged Navier-Stokes
2Large-Eddy Simulation

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Inria Annual Report 2023

on the terms of the models, and on which criteria, to switch from RANS to LES; how to improve the
robustness of the method with respect to the choices made by the user (in particular the mesh). Our
research work, described below, aims at answering these questions.

Today, even though the industrial demand for more accurate and robust RANS models is very sig-
nificant, very few academic teams are active in this field (for instance, [118, 88, 60, 123]), most of them
being participants to the European ERCOFTAC SIG-15 group of which we are an active member. In
France, we collaborate or have recently collaborated with most of the teams, mainly in the industry
(EDF, Dassault, PSA, SAFRAN) or applied research organizations (ONERA, CEA). The CAGIRE team is
particularly renowned for its work on the interaction between turbulence and the wall by elliptic blending
(EB-RSM, [99, 102]), and is solicited by these partners to improve the representation of complex effects
on turbulence (buoyancy, conjugate heat transfer, adverse pressure gradients, impingement, etc.).

Concerning the development of original hybrid RANS/LES approaches, the main contributions in
France are due to ONERA (ZDES [74] and PITM [71]); IMF Toulouse in collaboration with the ECUADOR
team of the Inria center of Sophia-Antipolis (OES [66, 108]) and CAGIRE (HTLES [97, 59, 80, 65]). The
originality of our work is two-fold: (i) through temporal filtering, a formally consistent link is provided
between the equations of motion and the hybridization method in order to reduce the level of empiricism,
which is, for non-homogeneous turbulence, along with the additive filter method [84, 57], one of only
two methods capable of providing such a consistent framework; (ii) through the development of an active
approach based on the Anisotropic Linear Forcing (ALF) [15] and an adaptive strategy that autonomously
determines the LES zone and refines the mesh based on physical criteria [21], a new Continuous Embedded
LES paradigm is proposed, which is a realisation of the agility concept at the center of our project.

3.2 High-order numerical methods and efficient algorithms

When dealing with RANS models, a second order finite volume method is usually used. In our project, we
aim at addressing hybrid RANS/LES models, which include some regions in which essentially unstationary
processes are approximated in LES regions. This usually requires to use low dissipative high order
numerical methods. If a consensus has emerged for years on second order finite volume methods for the
approximation of RANS models, investigations are still ongoing on finding the high order method that
would be the best suited with the compressible Navier-Stokes system.

As far as high order numerical methods are concerned, they are addressed at Inria essentially by the
Atlantis, Makutu, Poems and Rapsodi teams for wave-matter interaction problems, the Serena and Coffee
project-team on porous media, the Tonus team on plasma physics problems, and the Acumes, Gamma,
Cardamom and Memphis teams for systems that are closer of ours (shallow-water or compressible Euler).
As far as we know, only the Cardamom and Gamma teams are using high order methods with turbulence
models, and we are the only one to aim at hybrid RANS/LES models with such methods.

Our objective is to develop a fast, stable and high order code for the discretization of compressible
Navier-Stokes equations with turbulence models (Reynolds-stress RANS models and hybrid RANS/LES
methods) on unstructured meshes. From a numerical point of view, this raises several questions: how
to derive a stable numerical scheme for shocks without destroying the order of accuracy, how to derive
stable boundary conditions, how to implement the method efficiently, how to invert the system if implicit
methods are used?

Concerning aeronautical applications, several groups are working on discontinuous Galerkin methods:
in Europe, some of the groups participated to the TILDA project 3 (DLR, ONERA, CERFACS, Imperial
College, UCL, Cenaero, Dassault, U. of Bergamo). As far as we know, none of them considered Reynolds-
stress RANS models or hybrid RANS/LES models. Worldwide, we believe the most active groups are the
MIT group 4, or Ihme’s group5 which is rather oriented on combustion. Concerning HPC for high order
methods, we carefully follow the advances of the parallel numerical algorithm group at Virginia Tech,
and also the work around PyFR at Imperial College. Both of these groups are considering imperative
parallelism, whereas we have chosen to consider task based programming. Task based parallelism
was considered in the SpECTRE code [95] based on the Charm++ framework, and within a European

3https://cordis.europa.eu/project/id/635962
4https://www.gas-turbine-lab.mit.edu/
5http://web.stanford.edu/group/ihmegroup/cgi-bin/MatthiasIhme/

Project CAGIRE

5

project6, based on IntelTBB, but only for hyperbolic systems whereas we wish to address the compressible
Navier-Stokes system.

3.3 Compressible and multiphase flows

In this section, we are interested in two specific regimes of compressible flows: low Mach number flows
and compressible multiphase flows.

Low Mach number flows (or low Froude for Shallow-Water systems) are a singular limit, and therefore
raise approximation problems. Two types of numerical problems are known: if convective time scales
are considered, semi-implicit time integration is often preferred to explicit ones, because the acoustic
CFL is very restrictive compared with the convective one in the low Mach number limit [75]. The second
numerical problem at low Mach number is an accuracy problem. The proposed fixes consist in changing
the numerical flux either by centering the pressure [114] or are variant of the Roe-Turkel fix [85]. Over the
last years, we have been more focused on the accuracy problem, but our major originality with respect to
other groups is to be interested in the acoustic wave propagation in low Mach number flows, which may
also raise problems as first remarked in [107].

Understanding and controlling complex and physically rich flows, such as unsteady multiphase
compressible flows, are of great importance in various fields such as aeronautics, automotive, aerospace,
nuclear energy, naval and also medicine. If we note the efforts established so far to partially respond to
the problems linked to these flows, we also note major remaining challenges, particularly when different
spatial and temporal scales or multiple physical phenomena, such as phase change, viscoelasticity or
more generally interactions with solids, are to be considered. Good examples are cavitating flows such
as the ones encountered around naval propellers where cavitation pockets form at the vicinity of the
blades and lead to a turbulent bubbly flow in the wake [115]. Or in biomedical applications such as
in lithotripsy (treatment for kidney stones) [112] or, recently, histotripsy (non-invasive treatment for
cancers) [94] where cavitation bubbles, induced by shock waves, laser energy deposit or high-intensity
focused ultrasound waves, violently collapse and interact with biomaterials. In this context, we aim
to tackle the particularly challenging and ambitious modelling of these extremely complex multiphase
compressible flows where numerous scientific and technical obstacles remain to be overcome. Among
them, we could cite:

• The modelling of multiscale features including the simultaneous and dynamical computation of
sub-grid dynamics (inclusions such as bubbles or drops) and of resolved interfaces. The derivation
of averaged compressible multiphase models is currently less active than in the 2000s, and only few
teams are interested in such problems. Recent advances were made at RWTH [87], and also mostly
in France at EDF R&D by J.M. Hérard or also by Bresch and Hillairet [68]. This low interest in this
type of challenging modeling and mathematical analysis was noticed in the review paper [117] as
an obstacle for the improvement of numerical methods. Hence, the driving idea of this project to
focus our efforts on the modeling of subscale phenomena, in particular by a stochastic process
[111].

• The modelling of biomaterials under a fluid-mechanics formulation including viscoelastic beha-
viour and realistic equations of state, and the modelling of bubbles containing simultaneously
condensable and non-condensable gases. The simultaneous coupling of compressible, multi-
component flow models with viscoelastic solids and mass transfer will enable us, through simula-
tions, to understand the fundamental physics taking place in several medical applications involving
bubble dynamics [67]. This will therefore fill the knowledge gap on the subject involving significant
range of physical phenomena that are not well understood yet, and for which experiments often
lack insight, and spatial and temporal resolution [64]. This will potentially lead to significant
improvements of the current and future medical treatments regarding their success rate, cost and
safety.

6https://exahype.eu/

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Inria Annual Report 2023

3.4 Analysis and simulation of turbulent flows and heat transfer

The numerous discussions with our industrial partners make it possible to define configurations to
carry out comparison between computations and experiments aimed at validating the fundamental
developments described in the previous sections. Reciprocally, the targeted application fields play an
important role in the definition of our research axes, by identifying the major phenomena to be taken
into account. This section gathers applications which essentially deal with turbulent internal flows, most
often with heat transfer.

Detailed data are required for a fine validation of the methods. In addition to the active participation
and co-organizing of the SIG-15 group of the ERCOFTAC network, which gives us access to various
experimental or DNS data and enables us to carry out model and code benchmarking exercises with other
European teams [96, 98, 62, 101], we generate experimental data ourselves when possible and develop
collaborations with other research groups when necessary (ONERA, institute Pprime, CEA).

Historically, the scientific convergence between the team members that led to the development of
our project and the creation of the CAGIRE project-team in 2016 was based on scientific themes related
to aeronautical combustion chambers (hence the term internal flows in the name of the team), with our
industrial partners SAFRAN and Turbomeca (now SAFRAN-Helicopter Engines). If the scientific and ap-
plication themes of the team are now much more diverse, these applications to aeronautical combustors
are at the origin of the existence of the MAVERIC experimental facility, allowing the study of turbulent
flows at low Mach number over multi-perforated walls subjected to a coupling with acoustic waves,
representative of the flows in combustors. This wind tunnel is thus complementary to those developed at
ONERA, with which we collaborated [113] when it was necessary to add thermal measurements, within
the framework of the European project SOPRANO.

4 Application domains

4.1 Aeronautics

Cagire is active in the field of aeronautics through the following activities:

• The combustion chamber wall: the modelling, the simulation and the experimentation of the
flow around a multiperforated plate representative of a real combustion chamber wall have been
focused on during the recent period. The continuous improvement of our in-house test facility
Maveric is also an important ingredient to produce our own experimental validation data for
isothermal flows. For non-isothermal flows, our participation in the EU funded program Soprano
gave us access to non-isothermal data produced by Onera. This activity is also included in the
E2S-UPPA project Asturies.

• The flow around airfoils: the modelling of the turbulent boundary layer has been for almost a
century a key issue in the aeronautics industry. However, even the more advanced RANS mod-
els face difficulties in predicting the influence of pressure gradients on the development of the
boundary layer. A main issue is the reliability of the modelling hypotheses, which is crucial for less
conservative design. One of the technological barriers is the prediction of the flow in regimes close
to the edge of the flight domain (stall, buffeting, unsteady loads) when the boundary layer is slowed
down by an adverse pressure gradient. This was the subject of the CIFRE PhD thesis of Gustave
Sporschill in collaboration with Dassault Aviation.

• Impinging jets: because of their high heat transfer efficiency, turbulent impinging jets are commonly
used in a large variety of applications, and in particular blade cooling systems. Understanding the
underlying physics of the mechanisms at play is of prime interest and is still an open question.
Additionally, this configuration remains a challenging test case for turbulence models since it
embraces many flow features despite a relatively simple geometry, and causes strong discrepancies
between standard turbulence closures. Reynolds stress transport models have been shown to be
promising candidates but still suffer from a lack of validation regarding this flow configuration.
Such models are the subject of a collaboration with Onera and a starting collaboration with SAFRAN
HE (CIFRE PhD thesis of Jules Mazaleyrat).

Project CAGIRE

7

• Atmospheric reentry problem: When a body enters the atmosphere with a high velocity, its tra-
jectory is mainly driven by the hypersonic flow surrounding the body. The integrity of the body is
maintained by a shield that is progressively ablated. The sharp control of the motion is possible
with a very good knowledge of the surrounding hypersonic flow and of its interaction with the
ablated shield. Within the SEIGLE project, the team is involved in the simulation of the interaction
of a droplet (representing the ablated body) and a hypersonic flow. In the Asturies project, the aim
is to study the improvement on the shock/turbulence interaction by using advanced RANS models
(second-moment closure).

4.2 Energy

• The prediction of heat transfer in fluid and solid components is of major importance in power
stations, in particular, nuclear power plants. Either for the thermohydraulics of the plenum or in
the study of accidental scenarii, among others, the accurate estimation of wall heat transfer, mean
temperatures and temperature fluctuations are necessary for the evaluation of relevant thermal
and mechanical design criteria. The PhD thesis (CIFRE EDF) of G. Mangeon, was dedicated to the
development of relevant RANS models for these industrial applications [103, 27]. The collaboration
with EDF is pursued within the ANR project MONACO_2025 and via the just started CIFRE PhD
thesis of Corina Sanz Souhait.

• Moreover, the prediction of unsteady hydrodynamic loadings is a key point for operating and for
safety studies of PWR power plants. Currently, the static loading is correctly predicted by RANS
computations but when the flow is transient (as, for instance, in Reactor Coolant Pumps, due to
rotor/stator interactions, or during operating transients) or in the presence of large, energetic,
coherent structures in the external flow region, the RANS approach is not sufficient, whereas LES is
still too costly for a wide use in the industry. This issue was the main focus of the PhD thesis (CIFRE
EDF) of Vladimir Duffal, and is pursued within the ANR project MONACO_2025.

• For the design of high temperature solar receiver for concentrated solar power plants, flows are
characterized by strong variations of the fluid properties, such that, even in the forced convection
regime, they significantly deviate from isothermal flows, with a possible tendency to relaminarize,
which can significantly reduce heat transfer. A better understanding and modeling of the physical
mechanisms observed in turbulent flows with strong temperature gradients are important and was
the focus of a recent collaboration with the LaTeP laboratory of UPPA.

• Thermal storage is interesting to decorrelate the production of heat or cold from its use whether for
direct operation for a heat network (smoothing of heat supply to meet intermittent needs) or for
power generation (phase shift between heat generation and power generation). The challenge is to
study, via CFD, the dynamic and thermal behavior of the storage during the loading, resting and
discharge phases. This is the focus of the PhD thesis of Alexis Ferré, co-supervised by R. Manceau
and S. Serra (LaTeP).

4.3 Automotive propulsion

• The engine (underhood) compartment is a key component of vehicle design, in which the temperat-
ure is monitored to ensure the effectiveness and safety of the vehicle, and participates in 5 to 8% of
the total drag and CO2 emissions. Dimensioning is an aerodynamic and aerothermal compromise,
validated on a succession of road stages at constant speed and stopped phases (red lights, tolls,
traffic jam). Although CFD is routinely used for forced convection, state-of-the-art turbulence
models are not able to reproduce flows dominated by natural convection during stopped phases,
with a Rayleigh number of the order of 1010, such that the design still relies on costly, full-scale,
wind tunnel experiments. This technical barrier must be lifted, since the ambition of the PSA group
is to reach a full digital design of their vehicles in the 2025 horizon, i.e., to almost entirely rely on
CFD. This issue was the focus of the PhD thesis (CIFRE PSA) of S. Jameel, supervised by R. Manceau,
and also a part of the ANR project MONACO_2025 described in section 10.2.1, in the framework of
which S. Jameel was hired as a post-doc until July 2021 and S.K. Jena from January 2022.

8

Inria Annual Report 2023

• The Power & Vehicles Division of IFPEN co-develops a CFD code, CONVERGE, to simulate the
internal flow in spark-ignition engines, in order to provide the automotive industry with tools to
optimize their design. The RANS method, widely used in the industry, is not sufficiently reliable for
quantitative predictions, and is only used as a tool to qualitatively compare different geometries.
On the other hand, LES provides more detailed and accurate information, but at the price of a
CPU cost unafordable for daily use in the industry. Therefore, IFPEN aims at developing the hybrid
RANS/LES methodology, in order to combine the strengths of the two approaches. The PhD thesis
of Hassan Afailal, co-supervised by Rémi Manceau, was focused on this issue. In the framework of
the collaborative project ASTURIES (E2S-UPPA/Inria/CEA/IFPEN), this collaboration with IFPEN
will be pursued by the development of high-order methods in the CONVERGE code in order to
make it possible to perform highly accurate and low-dissipative LES and hybrid RANS/LES in
combustion engines.

4.4 Medical applications

Many medical applications exist where interactions between bubbles and biomaterials appear. CAGIRE
is interested in a better understanding of the fundamental physics involved in such interactions, leading
to improvements and innovation in current and future medical treatments with regard to their success
rate, cost and safety:

• Lithotripsy is a noninvasive (the skin is not pierced) procedure used to treat kidney stones that
are too large to pass through the urinary tract. Lithotripsy treats kidney stones by sending focused
ultrasonic energy or shock waves directly to the stone first located with fluoroscopy (a type of X-ray
“movie”) or ultrasound (high frequency sound waves). The shock waves break a large stone into
smaller stones that will pass through the urinary system. Lithotripsy allows persons with certain
types of stones in the urinary system to avoid an invasive surgical procedure for stone removal.
Lithotripsy involves cavitation bubbles as a primary or secondary mechanisms to attack the surface
of the stone. Regarding success rates, for patients who are thought to be good candidates for this
treatment, about 70 to 90 percent are found to be free of stones within three months of treatment.
Furthermore, one should note that lithotripsy may include, but are not limited to, complications
such as: bleeding around the kidney, infection, obstruction of the urinary tract by stone fragments,
stone fragments left that may require more lithotripsies.

• Histotripsy is the first noninvasive, non-ionizing, and non-thermal ablation technology guided
by real-time imaging. Using focused ultrasound delivered from outside the body, histotripsy
mechanically destroys tissue through cavitation, rendering the target into acellular debris. The
material in the histotripsy ablation zone is absorbed by the body within 1-2 months, leaving
a minimal remnant scar. Histotripsy has also been shown to stimulate an immune response
and induce abscopal effects in animal models, which may have positive implications for future
cancer treatment. Histotripsy has been investigated for a wide range of applications in preclinical
studies, including the treatment of cancer, neurological diseases, and cardiovascular diseases.
Phase I human trials have shown the initial safety and efficacy of histotripsy to treat patients
with malignant liver tumors, BPH, and calcified aortic stenosis. Despite substantial technical,
preclinical, and clinical progress to date, there is a large amount of future work necessary for
technical development, preclinical research, and human studies before histotripsy can become a
wide-spread clinical treatment modality.

• Drug delivery. Gas-filled microbubbles can be designed with drug- and gas-loaded interiors. A
stabilizing coating surrounds the bubble which may be targeted to specific tissue by incorporating
protein ligands on the surface. Drugs can be incorporated by themselves or, if insoluble in water,
in an oil layer. Among the possible therapies, the most exciting is the possibility of the delivery
of genetic material to a chosen site. Focused ultrasound is then used to cavitate the gene-loaded
microbubble and the shockwaves or microjets thus generated cause the genetic material to be
injected into the surrounding cells. This technology can also be combined with endothelial cell
barrier opening, which is performed prior the drug delivery. Indeed, the ultrasound irradiation of
microbubbles produces jets which open the barrier for a few hours. This promotes the passage of
large drug molecules necessary for specific treatments such as that of Alzheimer’s disease.

Project CAGIRE

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5 Social and environmental responsibility

Impact of research results

The availability of improved RANS models and hybrid RANS/LES methods offering a better physical
representativeness than models currently used in the industry, at a reasonable computational cost, will
make it possible to improve the reliability of industrial numerical simulations, and thus to better optimize
the systems, in order to reduce the environmental impact of transportation and industrial processes, and
to improve the safety of installations and reduce the risks of accidental pollution.

Moreover, previous applications of hybrid RANS/LES methods have shown that it is possible to obtain
an accuracy equivalent to LES with an energy consumption of the simulation reduced by a factor of
about 200. This gain can be considerably increased in a complete industrial simulation with a much
higher Reynolds number, leading to a drastic reduction of the environmental impact of the simulations
themselves.

6 Highlights of the year

• Cagire organized the 17th ERCOFTAC SIG15 / MONACO_2025 workshop on turbulent natural
convection flows, 19-20 January 2023, Pau, France7. This event, coordinated by R. Manceau,
brought together 25 people from different countries, and was both one of the periodic workshops of
the SIG-15 group of the ERCOFTAC European network, and the closing event of the MONACO_2025
ANR project.

• Discussions for a new collaboration with CEA Gramat were held during this year and the work
will officially start during 2024. The collaboration will mainly consist of the funding of future PhD
students. The first scientific subject to tackle concerns the numerical simulation of the attenuation
of the effects of an explosion by an aqueous foam. Other subjects will follow such as the atomization
of liquids resulting from the passage of a undeformable projectile at high speed through a barrel.

• A new collaboration with ETH Zürich and Storz Medical, a medical technology manufacturer, has
started this year and concerns discovering the contribution of cavitation damage in kidney stone
ablation. This work implies experiments using a medical extracorporeal shock wave lithotripter
and X-rays visualizations that will take place at the European Synchrotron Radiation Facility in
February 2024. These experiments will also allow us to better assess the quality of future state-of-
the-art simulations. The latter will constitute the first stones for following studies using exploratory
technology for kidney stone ablation.

• A second collaboration has also started this year with ETH Zürich and concerns the use of both
experiments and simulations to explore a new drug-delivery technique. It uses the interaction of a
shock wave with an encapsulated droplet within a bubble. The droplet would contain the drug. The
shock induces a strong collapse of the bubble which significantly enhances the atomization of the
droplet. This also helps to choose the target location instead of disseminating the drug throughout
the whole body’s blood circulatory system.

• After a few years of suspended activity, the collaboration with SAFRAN Helicopter Engines was
revived at the end of 2023 through the CIFRE thesis of Jules Mazaleyrat, also co-supervised by
ONERA. This thesis is devoted to improving the EB-RSM turbulence model, which we have been
developing for many years, in the context of applications linked to cooling by jet impingement of
turbine blades in helicopter engines.

• A new activity started this year in cooperation with Prof. S. Elaskar from the National University
of Córdoba (Argentina). It is aimed at extending to reactive turbulent gaseous flows the temporal
LES approach developed by the team for inert flows in a hybrid RANS-LES context. During the
two-week visit of Prof. S. Elaskar, the problem of deriving a filtered chemical production term for
the premixed turbulent combustion progress variable was addressed.

7https://project.inria.fr/monaco2025ercoftacsig15workshop/

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Inria Annual Report 2023

7 New software, platforms, open data

7.1 New software

7.1.1 AeroSol

Keywords: High order finite elements, Parallel computing

Functional Description: The AeroSol software is a high order finite element library written in C++. The
code has been designed so as to allow for efficient computations, with continuous and discon-
tinuous finite elements methods on hybrid and possibly curvilinear meshes. The work of the
team CARDAMOM (previously Bacchus) is focused on continuous finite elements methods, while
the team Cagire is focused on discontinuous Galerkin methods. However, everything is done for
sharing the largest part of code we can. More precisely, classes concerning IO, finite elements,
quadrature, geometry, time iteration, linear solver, models and interface with PaMPA are used by
both of the teams. This modularity is achieved by mean of template abstraction for keeping good
performances. The distribution of the unknowns is made with the software PaMPA , developed
within the team TADAAM (and previously in Bacchus) and the team Castor.

News of the Year: Highlights for the year 2023 concern:

- Functional tests: development of a python tool that will be included in the ‘ci‘, based on ‘pytest‘.
Reference files, storing artifacts of the executions of the tests are generated, and the ‘ci‘ relaunch
these tests and check the non-regression of the stored artifacts. Fix some feature in ‘ci‘ and parallel
‘ci‘ on Plafrim - Postprocessing tools were developed on the artifacts files for computing the order
of convergence and for plotting the error. - Several bug fixes (geometrical partitioning, NetCDF) -
Refactorization of the degrees of freedom handling. This should help the transition from PaMPA to
DM2 - Development of finite element basis and numerical schemes that preserve discretely curl
or divergence with the discontinuous Galerkin method. This induced major changes because the
degrees of freedom are no more accessed as [idof x nvar + ivar ] but in a transposed manner with a
non regular pattern for the degrees of freedom. Implementation of initialization, error computation,
a.s.o, and implementation of hyperbolic integrators with these new finite elements. - Development
of covariant and contravariant geometrical transformations. - Some work was done on the macros
using PaMPA for preparing the transition to DM2. - Induction model, two dimensional rotated
waves model. - Computation of semi-norm grad and div in the sense of distributions.

URL: https://team.inria.fr/cardamom/aerosol/

Contact: Vincent Perrier

Participants: Mario Ricchiuto, Vincent Perrier, Heloise Beaugendre, Christopher Poette, Marco Lorini,
Jonathan Jung, Anthony Bosco, Luca Cirrottola, Romaric Simo Tamou, Ibtissem Lannabi, Matthieu
Haefele

7.1.2 DM2

Name: Distributed Mesh and Data Manager

Keywords: HPC, Data parallelism, High order finite elements, Unstructured meshes, Hybrid meshes

Functional Description: DM2 is a C++ library for managing mesh and data on mesh in a MPI parallel
environment. It is conceived to provide parallel mesh and data management in high order finite
element solvers for continuum mechanics.

The user should provide a mesh file which is read by the library. Then DM2 is able to:

- Read the mesh, and read the data provided in the mesh file, possibly in parallel

- Redistribute the mesh in order to distribute the data on a given set of processors. This redistribu-
tion is made through a graph partitioner such as PARMETIS or PT-SCOTCH.

- Allocate the memory in parallel if a number of unknown by entity type is provided by the user.

Project CAGIRE

11

- Centralize the data.

- Compute the halo required for a numerical method. The halo is adapted for each of the possible
discretization.

- Renumber mesh elements for making a difference between mesh elements that need or need not
communication.

- Aggregate a mesh based on a metric for developing a multigrid method.

Release Contributions: This version introduces overlap regions ("halos") among distributed mesh par-
titions. These halos are specialized for discontinuous or continuous schemes, but generic with
respect to the (geometric) degree of the mesh cells. These halos allow to synchronize numerical data
defined on a set of entities of the distributed mesh. Numerical data is again generic with respect
to the degree of their polynomial approximation, the number and combinations of scalar/vector
fields, and the size of the vector spaces.

News of the Year: Contributions of this year are integrated in version v0.1. This version introduces
overlap regions ("halos") among distributed mesh partitions. These halos are specialized for
discontinuous or continuous schemes, but generic with respect to the (geometric) degree of the
mesh cells. These halos allow to synchronize numerical data defined on a set of entities of the
distributed mesh. Numerical data is again generic with respect to the degree of their polynomial
approximation, the number and combinations of scalar/vector fields, and the size of the vector
spaces. The continuous integration framework testes each commit on several 2D/3D hybrid meshes
on which parallel mesh distribution and halos construction is performed, for each geometric and
polynomial degree up to 4. Main classes are also covered by a set of unit tests.

Contact: Vincent Perrier

Participants: Vincent Perrier, Luca Cirrottola

7.1.3 UHAINA

Keywords: Simulation, Ocean waves, Unstructured meshes, Finite element modelling

Scientific Description: Operational platform for near shore coastal application based on the following

main elements:

- Fully-nonlinear wave propagation.

- Wave breaking handled by some mechanism allowing to mimic the energy dissipation in breakers.

- A high order finite element discretization combined with mesh and polynomial order adaptation
for optimal efficiency.

- An efficient parallel object oriented implementation based on a hierarchical view of all the data
management aspects cared for by middle-ware libraries developed at Inria within the finite element
platform Aerosol.

- A modular wrapping allowing for application tailored processing of all input/output data (includ-
ing mesh generation, and high order visualization).

- Spherical coordinates based on a local projection on a real 3D spherical map (as of 2021)

- Compilation with GUIX available (as of 2022)

- Homogenization and standardization of code outputs and hazard quatification (as of 2022)

- Correction of the management of dry/wet fronts in the presence of structures represented by a
single high point (as of 2022)

- Use of FES for the calculation of the tide directly in UHAINA through an API. New compilation
option for activation (as of 2022)

- Boundary conditions accounting tides from FES and corrected with the effect of the inverse
barometer, for the simulation of the tidal propagation and the surge on domains at the regional
scale (as of 2022)

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Inria Annual Report 2023

- Hydraulic connections (e.g. sewers) in the simulation of urban flooding (as of 2022)

- Mass source term, for the injection of the volume of water overtopping structures not accounted
in the elevation model during flooding episodes by sea surges (as of 2022)

Functional Description: Waves simulation

Contact: Mario Ricchiuto

Participants: Mario Ricchiuto, Philippe Bonneton, David Lannes, Fabien Marche

Partners: EPOC, IMAG, IMB

7.1.4 ECOGEN

Keyword: Numerical simulations

Functional Description: ECOGEN is a CFD platform dedicated to numerical simulation of compressible
multiphase flows. It has the vocation to share academic research in the multiphase flow field with
other academics but also with industrials and students.

Multi-models (single phase, multiphase with or without equilibrium). Multi-physics (thermal
transfers, viscosity, surface tension, mass transfers). Multi-meshes (Cartesian, unstructured, AMR).
HPC.

News of the Year: A new release, ECOGEN_v4.0, is available on GitHub. It includes new features and

fixes bugs.

Major points: - Removed the version numbers of the input file names (break compatibility with
previous version). - Possibility to use finite pressure relaxation on UEq model for more than two
phases. - Possibility to initialize an unstructured simulation with the result of a previous simulation
performed on a similar mesh and/or a different number of CPUs. This feature is particularly useful
to fasten steady state convergence on a fine mesh using coarse mesh results. - PUEq phase-change
model (handled through PTMu relaxation) does not require mass fraction threshold anymore to
trigger mass transfer. - Add Moving Reference Frame coupling of a rotating region with a static one.
- Renamed boundary condition names (break compatibility with previous version). - Immersed
boundaries can be added in a Cartesian mesh domain (physicalEntity = -1).

Minor points: - Option to record boundary quantities such as pressure forces and shear stress (use-
ful for aerodynamic coefficient computation). - Possibility to display cells’ reference length on XML
output with unstructured mesh. - Add a tutorial on mesh mapping and low-Mach preconditionning
options. - Add scripts related to droplet shock-induced cavitation. - Improve variable name style for
Gnuplot output. - Increase code coverage by nonreg. - Updated AMR refinement criteria to match
the different modelling. - Always a little more source code translation from French to English. - A
wall is now considered as a symmetry BC if viscosity is ignored. - Update of documentation.

Fixes: - Fix the getTemperature() and copyPhase() methods for multiphase models. - Fix restart
bug when using alphaNull on PUEq model. - Fix bug on simulation progress when using iteration
control mode. - Fix a MPI data type that caused a crash during MPI_Allreduce on some compilers. -
Minor fix for Euler-Korteweg model. - Correction on UEq BC for volume fraction flux, using sM
instead of uStar to respect transport equation. - Update non-regression scripts to make them
compatible with OS X. - Correction for phase change with a second-order method.

URL: https://code-mphi.github.io/ECOGEN/overview/

Contact: Kevin Schmidmayer

Participants: Kevin Schmidmayer, Fabien Petitpas, Joris Cazé, Sébastien Le Martelot, Éric Daniel, Bene-

dikt Dorschner, Solène Schropff, Adedotun Ade-Onojobi, Fatima Gadiri

Partners: CNES, ETHZ, California Institute of Technology

Project CAGIRE

7.2 Open data

13

• The ORACLES database [70]: this large experimental database of measurements on a dump-
stabilized turbulent premixed flame has been built-up by aggregating results obtained on the
ORACLES test facility [110] and is now available on the Zenodo website.

8 New results

8.1 Turbulence modelling

8.1.1 Improvement of the EB-RSM RANS model

Participants:

Rémi Manceau.

External collaborators: Gustave Sporschill (formerly CAGIRE, now Dassault), F. Billard
(Dassault), M. Mallet (Dassault), A. Colombié (ONERA), F. Chedevergne
(ONERA), E. Laroche (ONERA), S. Benhamadouche (EDF), J.-F. Wald
(EDF).

In order to accurately represent the complexity of the phenomena that govern the evolution of turbu-
lent flows, an important part of our research focuses on the development of Reynolds-stress RANS models
that take into account the wall/turbulence interaction by an original approach, elliptic blending [99, 102].
Although this approach, has been successfully applied to various configurations (for instance [63]), in
order to take into account more subtle effects, during the theses of A. Colombié and G. Sporschill, in col-
laboration with ONERA and Dassault Aviation, respectively, we identified the importance of introducing
a specific pressure diffusion model to correctly reproduce the dynamics of turbulence in impingement
regions and in boundary layers subject to adverse pressure gradients, paving the way towards a wider
application of the EB-RSM in aeronautics [119, 72, 120, 121, 122]. This activity is continued via the PhD
thesis of J. Mazaleyrat in collaboration with SAFRAN HE and ONERA in the framework of turbine blade
cooling by jet impingement.

8.1.2 Extension of RANS turbulence models to mixed and natural convection

Participants:

Rémi Manceau, Puneeth Bikkanahally.

External collaborators:

S.M. Saad Jameel (formerly Cagire, now Plastic Omnium), V. Herbert
(PSA-Stellantis), F. Dehoux (formerly Cagire, now Framatome), S. Ben-
hamadouche (EDF), S.K. Jena (formely Cagire, now TU Delft).

In the mixed and natural convection regimes, as presented in three invited lectures [100, 101, 20], the
interaction mechanisms between dynamic and thermal fluctuations are complex and very anisotropic
due to buoyancy effects, so that the natural turbulence modelling level to take them into account is
second-moment closure, i.e., Reynolds-stress models. When associating the EB-RSM and the EB-DFM,
several modifications had to be introduced in natural convection for the scrambling term, the length
scale of the elliptic blending, and especially by substituting a mixed time scale for the dynamic time scale
in the buoyancy production term of the dissipation equation, which has a drastic positive impact on the
predictions in the natural convection regime. This work, carried out in collaboration with EDF, leads
to the first linear Reynolds-stress model able to accurately represent the wall/turbulence interaction
in forced, mixed and natural convection regimes [76]. However, some industrial partners, in particular

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Inria Annual Report 2023

PSA Group (now Stellantis), who encounter natural convection flows in the underhood compartment of
vehicles, do not wish to use such sophisticated models, so we have developed an algebraic version of the
Reynolds stress equation which thus constitutes an extension of the eddy-viscosity models (buoyancy-
extended Boussinesq relation), within the framework of S. Jameel thesis [89, 91, 90], which can be easily
implemented into any industrial and/or commercial CFD code. The application of such models to various
configurations of differentially-heated cavities showed that, depending on the situation, such buoyancy
extensions can have an influence ranging from very significant to negligible [92].

8.1.3 HTLES: an original hybrid RANS/LES model

Participants:

Rémi Manceau, Puneeth Bikkanahally, Mahitosh Mehta, Martin David.

External collaborators:

Vladimir Duffal (formerly Cagire, now EDF), B. de Laage de Meux
(EDF), H. Afailal (formerly CAGIRE, now IFPEN), Ch. Angelberger
(IFPEN), A. Velghe (IFPEN).

Regarding hybrid RANS/LES, we have developed the HTLES (hybrid temporal LES) approach. The
wall/turbulence interaction being fundamental for the applications of interest to EDF, V. Duffal’s thesis
[78] focused on the precise control of the transition from RANS to LES when moving away from the
wall, through the improvement of the theoretical link between the turbulent scales and the form of the
model equations, as well as the introduction of two different shielding functions to avoid the classical
grid-induced separation and log-layer mismatch [80, 79, 18], i.e., the strong erroneous sensitivity of the
results to the near-wall mesh. A significant result is that the study of wall pressure fluctuations and their
spectra on periodic hills showed that the HTLES approach could reproduce these spectra as well as LES,
down to a lower cut-off frequency than in LES due to the coarser mesh and the presence of the RANS
zone [78], which suggests encouraging prospects for the prediction of mechanical and thermal fatigue. In
the framework of the ANR project Monaco_2025, the thesis of P. Bikkanahally is devoted to the extension
of the HTLES approach to natural convection. In differentially heated cavities, due to the coexistence
of turbulent boundary layers and a laminar region in the centre, the shielding function introduced by V.
Duffal causes a deterioration of the results. Good results are obtained by using instead a new shielding
function based on the resolution of an elliptic relaxation equation [65, 17]. Moreover, the thesis of H.
Afailal, in collaboration with IFPEN, was dedicated to the development of the HTLES for the non-reactive
internal aerodynamics of spark ignition engines. The aim was to adapt this approach to non-stationary,
cyclic flows with moving walls, for which the main challenge was to provide a reliable evaluation of the
mean turbulent energy, which is a crucial parameter for the control of the transition from RANS to LES,
and is obtained by explicitly applying a differential temporal filter during the simulation to separate the
time-dependent mean and turbulent components of the flow [58].

8.1.4 Towards embedded LES

Participants:

Rémi Manceau, Pascal Bruel, Puneeth Bikkanahally, Mahitosh Mehta,
Martin David.

External collaborators:

Fabien Dupuy (GD-Tech), Olivier Jegouzo (GD-Tech), Fabien Renard
(GD-Tech).

In the framework of hybrid RANS/LES, a particularly attractive approach is Embedded LES, which
consists in reserving the LES to a small area included in a global RANS domain, which is a particular

Project CAGIRE

15

strategy for using the zonal hybrid RANS/LES. However, the zonal approach is characterized by a pre-
division between RANS and LES zones and a discontinuous interface, which prohibits any evolution of
the scale of description of turbulence during the calculation, which would allow an adaptability of the
model according to physical criteria determined during the calculation. Our objective is therefore to
develop embedded LES in the context of continuous approaches (CELES, Continuous Embedded LES), in
which the interface between RANS and LES is now a diffuse interface. In these approaches, the domain is
not split into sub-domains, but the model evolves in a continuous manner so that it tends towards a RANS
model or towards a LES model. The diffuse interface (grey area) is the transition area in which the model
transitions from a RANS model to a LES model. It is then necessary, as in the zonal approach, to enrich
the RANS solution by adding synthetic turbulence to avoid the drastic decrease of the total turbulent
stress at the beginning of the LES zone which would strongly degrade the results. In the framework of the
hybrid RANS/LES approach developed by Cagire, HTLES, this aspect consists in developing a volume
enrichment approach based on a fluctuating force [106, 15]. The development of such a CELES approach
is the main purpose of the just started CELTIC project (post-doc of P. Bikkanahally), in collaboration with
the SME GD-Tech. An adaptive determination of the RANS and LES regions based on physical criteria is
the subject of the post-doc of M. David, in the framework of the Asturies project.

8.1.5 Turbulent premixed combustion in the flamelet regime: developing a closure model for the

time filtered reaction rate

Participants:

Pascal Bruel.

External collaborator:

S. Elaskar (Universidad Nacional de Córdoba, Argentina).

The long-term objective pursued here is to extend the approach of temporal large-eddy simulation
to turbulent reactive flows. As a first step towards this goal, the flamelet regime of isenthalpic turbulent
premixed combustion was first considered. In such a regime, the combustion process can be represented
through the evolution of a single progress variable whose time evolution resembles a bi-valued telegraph
signal. We first concentrate on the reaction rate, leaving aside for the moment the question of the closure
of the filtered scalar flux. In a RANS approach, corresponding to an infinite time filter width, many models
are available to close the mean reaction rate as a function of the mean progress variable. So the question
raised now is: what happens to the relation between the filtered reaction rate and the filtered variable
when the time filter width remains finite ? To guide our thinking, the development of the capacity of
generating and filtering synthetic telegraph signals was deemed necessary. After considering in [22]
the possibility of using the so-called "poor man Navier-Stokes" approach, we start developing a fortran
code aimed at directly generating synthetic telegraph signals satisfying some a priori constraints so as to
mimick real signals measured in such a combustion regime. With such a tool, we were able to recover
the behavior of the filtered reaction rate for quasi-infinite time filter widths e.g. the RANS behavior. Our
future activity will now concentrate on the numerical study of filtering the synthetic progress variable
signal with finite time filter widths.

8.2 High-order numerical methods and efficient algorithms

8.2.1 Efficient implementation of flux-reconstruction methods for combustion

Participants:

Vincent Perrier.

External collaborators:

Julien Bohbot, Julien Coatléven, Romaric Simo-Tamou, Quang
Huy Tran.

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Inria Annual Report 2023

In the framework of the PhD thesis of Romaric Simo-Tamou, flux-reconstruction methods were
implemented, first in AeroSol for the Navier-Stokes system, and then in the Converge CFD code for
high order computation of combustion and for benefiting of AMR in this code. For these schemes, new
analyses of their dissipation and dispersion properties were performed and disseminated in [36].

8.2.2 Development of high order numerical schemes for axisymmetric turbulent flows

Participants:

Anthony Bosco, Jonathan Jung, Vincent Perrier.

Part of the Asturies project aims at deriving high order numerical schemes for turbulent compressible

flows in axisymmetric geometry. This year, the work was focused on the three following points:

1. The derivation of conservative formulation for general advection-diffusion conservation laws
in axisymmetric coordinates. This led to a new high order discontinuous Galerkin method for
axisymmetric coordinates, which is optimal order and in which the source term are unambiguously
discretized and defined. This work was disseminated in [12] and in an extended version [37].

2. The wall boundary conditions for a large family of turbulent models including the k − ε models
can be seen as a double boundary condition on one of the variables (for example homogeneous
Neumann and homogeneous Dirichlet on k) and no boundary condition on ε. A simplified version
of this model with these boundary conditions can be seen as a mixed formulation for a bi-Laplacian
equation, on which these types of boundary conditions are natural. Inspired by theses ideas, a
new discontinuous Galerkin method was developed for this type of boundary condition on the
simplified linear model, and was disseminated in [28].

8.3 Compressible and multiphase flows

8.3.1 Low-Mach-number schemes

Participants:

Jonathan Jung, Vincent Perrier, Ibtissem Lannabi, Esteban Coiffier.

External collaborators:

Thomas Galié.

Unfortunately, the only fix we found in our previous work that is accurate for high order acoustics
computation is not Galilean invariant. The fix of [69] was extended from isentropic Euler system to full
Euler system in [13].

Unfortunately, this fix is not Galilean invariant. This led us to try to tackle the problem in a different
way from the numerical flux modification. We raised more fundamental questions on the connection
between the low Mach number spurious mode responsible for a low accuracy and the long time behaviour
of the wave system. In [14], we proved that on some finite domain configurations, the long time limit of
the wave system exists, and that a numerical flux is low Mach number accurate if and only if its low Mach
number acoustic development has a consistent long time behaviour. The spurious mode on the velocity
at low Mach number can therefore be identified using the long time limit of the asymptotic acoustic
system. Once this spurious mode is sharply identified, it can be filtered. This result is published in [93].
Still based on this filtering method, a spurious mode was identified in the velocity obtained by the low
Mach number fix which consists in centering the pressure gradient. This spurious mode may jeopardize
the mesh convergence of the velocity [25]. We also had the opportunity to disseminate our previous work
on low Mach number flows at different conferences [29, 25], included invited ones [19].

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8.3.2 Multi-scale multiphase flows

Participants:

Vincent Perrier, Kevin Schmidmayer.

As far as multiphase models are concerned, based on the ideas of [77], we have revisited the derivation
of Baer-and-Nunziato models [61]. Usually, models are derived by averaging the Euler system; then the
system of PDE on the mean values contains fluctuations which are modeled, often leading to relaxation
terms and interfacial velocity and pressure which should also be modeled. This can be achieved by
using physical arguments [116] or by ensuring mathematical properties [73]. In [111], we have followed
a slightly different path: we have supposed that the topology of the different phases follows an explicit
model: the sign of a Gaussian process. Some parameters of the Gaussian process (mean, gradient of the
mean) are linked with the averaged values of the flow (volume fraction), whereas others (auto-correlation
function) are linked with the subscale structure of the flow. The obtained system is closed provided the
parameters of the Gaussian process are known. Also, the system dissipates the phase entropies. Under
some hypotheses that can be interpreted physically, asymptotic models can be derived in the interface
flow limit or in the limit where the two fluids are strongly mixed. In these limits, different previously
proposed models are recovered [116, 83], which does not necessarily ensure the same phase entropy
dissipation properties. This work was disseminated this year in the conference [33].

8.3.3 Shock-induced cavitation within a droplet

Participants: Kevin Schmidmayer.

External collaborators:

L. Biasiori-Poulanges (ETH Zürich, Switzerland).

In [11] and [16], we investigated the shock-induced cavitation within a droplet which is highly
challenged by the multiphase nature of the mechanisms involved. Within the context of heterogeneous
nucleation, we introduced a thermodynamically well-posed multiphase numerical model accounting
for phase compression and expansion, which relies on a finite pressure-relaxation rate formulation.
We simulated (i) the spherical collapse of a bubble in a free field, (ii) the interaction of a cylindrical
water droplet with a planar shock wave, and (iii) the high-speed impact of a gelatin droplet onto a
solid surface. The determination of the finite pressure-relaxation rate was done by comparing the
numerical results with the Keller–Miksis model, and the corresponding experiments of Sembian et
al. and Field et al., respectively. For the latter two, the pressure-relaxation rate was found to be µ =
3.5 and µ = 0.5, respectively. Upon the validation of the determined pressure-relaxation rate, we ran
parametric simulations to elucidate the critical Mach number from which cavitation is likely to occur.
Complementing simulations with a geometrical acoustic model, we provided a phenomenological
description of the shock-induced cavitation within a droplet, as well as a discussion on the bubble-cloud
growth effect on the droplet flow field. The usual prediction of the bubble cloud center, given in the
literature, was eventually modified to account for the expansion wave magnitude.

8.3.4 Modelling of visco-elastic solids in multiphase flows

Participants: Kevin Schmidmayer.

External collaborators: N. Favrie (Aix-Marseille Université, France).

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Inria Annual Report 2023

As a work in progress, an extension of the model of diffuse solid–fluid interfaces [109, 81] is proposed
to deal with arbitrary complex materials such as porous materials in presence of plasticity and damage.
These are taken into account through Maxwell-type models and are cast in the standard generalized
materials. The specific energy of each solid is given in separable form: it is the sum of a hydrodynamic
part of the energy depending only on the density and the entropy, an elastic part of the energy which is
unaffected by the volume change, and a compaction part taking into account the compaction effects. It
allows us to naturally pass to the fluid description in the limit of vanishing shear modulus. In spite of a
large number of governing equations, the model has a simple mathematical structure. The model is well
posed both mathematically and thermodynamically, i.e. it is hyperbolic and compatible with both laws
of thermodynamics. The resulting model can be applied in situations involving an arbitrary number of
fluids and solids. In particular, we are showing the ability of the model to describe complex plasticity
(Gurson [86]) and damage (Mazars [105]) models.

8.4 Analysis and simulation of turbulent flows and heat transfer

8.4.1 Effusion cooling

Participants:

Rémi Manceau, Pascal Bruel.

External collaborators:

Ph. Reulet (ONERA), E. Laroche (ONERA), D. Donjat (ONERA),
F. Mastrippolito (formerly CAGIRE, now SAFRAN HE).

As regards wall cooling by effusion (multiple jets in crossflow), our MAVERIC experimental facility does
not allow us to carry out thermal measurements, so we approached ONERA Toulouse to collaborate on the
effects of gyration (angle of the jets with respect to the incident flow) on the heat transfer between the fluid
and the wall, within the framework of the European project SOPRANO. We then took up the challenge of
carrying out RANS simulations with the EB-RSM model on a configuration of unprecedented complexity
for us, consisting of 10 rows of 9 holes, in 90-degree gyration, representative of effusion cooling problems
in aeronautical combustion chambers. Comparisons between calculations and experiments have shown
the relevance of using the EB-RSM model and the importance of taking into account conjugate heat
transfer [113, 104]. In the framework of the Asturies project, the case, the database of a jet in crossflow
measured in the MAVERIC facility is currently under investigation with the adaptive strategy developed
by M. David, in order to serve as a demonstrator of this agile simulation method.

8.4.2 Thermocline energy storage

Participants:

Rémi Manceau, Alexis Ferré.

External collaborators:

S. Serra (LaTEP, UPPA), J. Pouvreau (CEA), A. Bruch (CEA).

A collaboration started at the end of 2020 with the CEA LITEN in Grenoble and the LaTEP of UPPA
on thermocline energy storage. An experimental facility is being developed at the CEA and RANS
simulations are underway to understand the dynamics of this type of flows, to determine the influence of
the turbulence generated by the filling of the tank on the quality of the thermocline, in order to optimize
the system and provide data to support the development of 1D models used in the optimization of
heat networks. A particular attention has been paid to the approximation used for variations of density
with temperature. Due to the wide range of temperatures, it was shown that the standard Boussinesq

Project CAGIRE

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approximation is not valid but a quadratic Boussinesq approximation was proposed, which gives results
very close to the more complex low-Mach number approximation, with a computational cost reduced by
a factor of two and an improved numerical stability [82, 23].

9 Bilateral contracts and grants with industry

Participants: Rémi Manceau, Vincent Perrier, Jonathan Jung, Pascal Bruel, An-
thony Bosco, Mahitosh Mehta, Martin David, Romaric Simo Tamou,
Alexis Ferré, Esteban Coiffier.

9.1 Bilateral contracts with industry

• CEA: “Agile simulation of turbulent internal flows”, contract in the framework of the Asturies project.

• CEA: “Collaboration contract for the PhD thesis of A. Ferré".

• CEA: “Collaboration contract for the PhD thesis of E. Coiffier".

• IFPEN: “Collaboration contract for the PhD thesis of Romaric Simo-Tamou".

9.2 Bilateral grants with industry

• CEA: “CFD and experimental study of a thermocline-type thermal storage for an optimized design
and data entry of component scale models in the framework of a multi-scale approach”, PhD
student Alexis Ferré.

• CEA: “Development of Fast, Robust and Accurate numerical methods for turbulence models on

Complex Meshes” (1/2 Grant), PhD student Anthony Bosco.

• CEA: “Analyse et simulation numériques de discrétisations décalées en thermohydraulique diphasique”,

PhD student Esteban Coiffier.

• IFPEN: "Développement de schémas d’ordre élevé pour un solveur cartésien / AMR pour la modél-

isation LES de la combustion.", PhD student Romaric Simo-Tamou.

10 Partnerships and cooperations

10.1 International research visitors

10.1.1 Visits of international scientists

Other international visits to the team

Sergio Elaskar

Status: Professor.

Institution of origin: National University of Córdoba.

Country: Argentina.

Dates: November 6 to November 18.

Context of the visit: Follow-up of the A17A07 Ecos Sud project.

Mobility program/type of mobility: CNRS funded research stay.

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Inria Annual Report 2023

10.2 National initiatives

10.2.1 ANR MONACO_2025

Participants:

Rémi Manceau, Puneeth Bikkanahally.

This project started in 2018 and ended in 2023. The ambition of the MONACO_2025 project, coordin-
ated by Rémi Manceau, was to join the efforts made in two different industrial sectors in order to tackle
the industrial simulation of transient, turbulent flows affected by buoyancy effects. It brings together two
academic partners, the project-team Cagire hosted by the university of Pau, and the institute Pprime of
the CNRS/ENSMA/university of Poitiers (PPRIME), and R&D departments of two industrial partners, the
PSA group and the EDF group, who are major players of the automobile and energy production sectors,
respectively.

• The main scientific objective of the project is to make a breakthrough in the unresolved issue of
the modelling of turbulence/buoyancy interactions in transient situations, within the continuous
hybrid RANS/LES paradigm, which consists in preserving a computational cost compatible with in-
dustrial needs by relying on statistical approaches where a fine-grained description of the turbulent
dynamics is not necessary. The transient cavity flow experiments acquired during MONACO_2025
will provide the partners and the scientific community with an unrivalled source of knowledge of
the physical mechanisms that must be accounted for in turbulence models.

• The main industrial objective is to make available computational methodologies to address di-
mensioning, reliability and security issues in buoyancy-affected transient flows. It is to be em-
phasized that such problems are not tackled using CFD at present in the industry. At the end of
MONACO_2025, a panel of methodologies, ranging from simple URANS to sophisticated hybrid
models based on improved RANS models, was evaluated in transient situations, against the dedic-
ated cavity flow experiments and a real car underhood configuration. This final benchmark exercise
will form a decision-making tool for the industrial partners, and will thus pave the way towards
high-performance design of low-emission vehicles and highly secure power plants. In particular,
the project is in line with the Full Digital 2025 ambition, e.g., the declared ambition of the PSA
group to migrate, within the next decade, to a design cycle of new vehicles nearly entirely based on
CAE (computer aided engineering), without recourse to expensive full-scale experiments.

10.2.2 ANR LAGOON

Participants:

Vincent Perrier.

The ANR project Lagoon was funded by ANR in 2021 within the section CE46 - Modèles numériques,

simulation, applications.

Coastal areas host around 10% of the world’s population and a huge amount of economic activities.
Climate change is expected to increase coastal flooding hazard in years to come. In this project, we
propose to develop a numerical tool for the stormsurges predictions.

For four years, a joint effort between the partners of this project among others has been done for
the development of a numerical tool able to tackle planetary computations with high resolution at the
coast: the Uhaina code, based on top of the AeroSol library. The scope of this project is to increase the
computational performance of our modelling platform, in order to upgrade it as an efficient and accurate
tool for storm-surge predictions in different future climate scenarios. To achieve this goal and producing
results which go beyond the state-of-the-art, our efforts will be focused on the following numerical and
informatics developments, devoted to decrease the run time of the model in operational conditions:

• Development of low-Froude accurate Implicit-Explicit (ImEx) time integration strategy.

Project CAGIRE

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• Development of scalable aggregation-based multigrid methods for addressing the efficiency of the
inversion of the (non)linear systems induced by implicit time stepping. For the data generation,
two stages IO, in-situ and in-transit data post-processing are strategies that will be evaluated with
existing technologies and will be implemented to improve the performance of the production code.

• The numerical tool will be validated on 1979-2014 sea level reanalysis, and be used for the genera-

tion of a database of sea level projections on future climate CMIP6 projections.

The code developed within this project will be freely distributed, with a strong effort put on reprodu-
cibility of results. Data generated for both the sea level reanalysis and the database of sea level projection
for future climate projections will be distributed towards the community.

10.2.3 ASTURIES

Participants: Rémi Manceau, Vincent Perrier, Jonathan Jung, Pascal Bruel, An-

thony Bosco, Mahitosh Mehta, Romaric Simo Tamou, Martin David.

Call: ISite E2S UPPA "Exploring new topics and facing new scientific challenges for Energy and

Environment Solutions"
Dates: 2020-2024
Partners: CEA CESTA ; IFPEN
In the context of internal turbulent flows, relevant to aeronautic and the automotive propulsion and
energy production sectors, ASTURIES aims at developing an innovative CFD methodology. The next gen-
eration of industrial CFD tools will be based on the only approach compatible with admissible CPU costs
in a foreseeable future, hybrid RANS/LES. However, state-of-the-art hybrid RANS/LES methods suffer
from a severe limitation: their results are strongly user-dependant, since the local level of description of
the turbulent flow is determined by the mesh designed by the user.

In order to lift this technological barrier, an agile methodology will be developed: the scale of de-
scription of turbulence will be locally and automatically adapted during the computation based on local
physical criteria independent of the grid step, and the mesh will be automatically refined in accordance.
Such an innovative approach requires the use of advanced near-wall turbulence closures, as well as
high-order numerical methods for complex geometries, since low-dissipative discretization is necessary
in LES regions. Morevover, the identification of relevant physical RANS-to-LES switchover criteria and
the refined validation of the method will strongly benefit from dedicated experiments.

The objectives of the project thus consist in:

• Proposing a robust and efficient implementation of elliptic relaxation/blending turbulence models

in the context of high-order Discontinuous Galerkine methods.

• Develop local physical criteria in order to get rid of the (explicit or implicit) dependence on the grid

step of the transition from RANS to LES.

• Develop an automatic remeshing strategy which ensures consistency with the self-adaptation of

the model.

• Validate the global methodology based on the 3 preceding points for configurations representative

of industrial internal turbulent flows.

The development of such a methodology, based on hybrid RANS/LES modelling, with low-dissipative
and robust numerical methods, independant of the initial design of a grid by the user, compatible with
unstructured meshes for complex industrial geometries, in the context of HPC, is thus the ambitious, but
reachable, objective of the project.

10.3 Regional initiatives

10.3.1 CELTIC

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Inria Annual Report 2023

Participants:

Rémi Manceau, Pascal Bruel, Puneeth Bikkanahally.

CELTIC (Continuous Embedded LES for Turbulent flows in Industrial Configurations) is a projet
accepted in the call ESR 2022 of the New-Aquitaine Region, in partnership with the local SME GDTech.
The project aims at proposing a new model of the forcing term allowing enrichment at the diffuse
interfaces between RANS and LES in continuous hybrid RANS/LES models for the simulation of turbulent
flows. This will make possible the development of an innovative simulation methodology, continuous
embedded LES (CELES), which consists in restricting the fine-grained model (LES) to regions where it is
necessary, surrounded by the rest of the domain using a statistical approach (RANS). The combination of
the fact that CELES will be based on hybrid RANS/Continuous LES approaches, easy to use in industrial
applications, and on a seeding by volume forcing applicable in all situations will make it a particularly
attractive method for the industry, which will bring to our industrial partner GDTech and its regional
customers (for example SAFRAN HE) a real value compared to the numerical simulation methods
available today.

11 Dissemination

Participants:

Rémi Manceau, Jonathan Jung, Vincent Perrier, Kevin Schmidmayer,
Pascal Bruel, Martin David, Mahitosh Mehta, Ibtissem Lannabi, An-
thony Bosco, Puneeth Bikkanahally Muni Reddy.

11.1 Promoting scientific activities

11.1.1 Scientific events: organisation

General chair, scientific chair

• R. Manceau organized the 17th ERCOFTAC SIG15 / MONACO_2025 workshop8. This workshop,
organized under the auspices of the SIG15 of the european ERCOFTAC network, which is also the
final workshop of the MONACO_2025 project, was held in Pau 19-20 January 2023.

Member of the organizing committees

• Member of the scientific committee of the International Symposium on Turbulence, Heat and Mass

Transfer since 2006 [R. Manceau]

11.1.2 Journals

Member of the editorial boards

• Advisory Board of International Journal of Heat and Fluid Flow [R. Manceau]

• Advisory Board of Flow, Turbulence and Combustion [R. Manceau]

Reviewer - reviewing activities

• Aerosp. Sci. Technol. [P. Bruel]

• Communications in Computational Physics (1) [V. Perrier]

• Computers and Fluids (3) [R. Manceau (2), J. Jung (1)]

• Computers and Mathematics with Applications 1) [ V. Perrier]

8https://project.inria.fr/monaco2025ercoftacsig15workshop/

Project CAGIRE

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• ESAIM Proceedings (1) [V. Perrier]

• Flow, Turbulence and Combustion (2) [R. Manceau]

• Int.J. Heat and Fluid Flow [R. Manceau]

• Int.J. Heat and Mass Transfer [P. Bruel]

• Int.J. Thermofluids (2) [R. Manceau]

• J. Computational Physics (4) [R. Manceau, V. Perrier (2), K. Schmidmayer]

• J. Fluid Mechanics (2) [R. Manceau, K. Schmidmayer]

• Physics of Fluids (2) [R. Manceau, K. Schmidmayer]

• Proceedings of the Royal Society A [K. Schmidmayer]

• Proceedings of FVCA10 conference [J. Jung]

11.1.3 Invited talks

[17] P. Bikkanahally and R. Manceau. ‘Modelling turbulent flows in the natural convection regime
using hybrid RANS-LES approaches’. In: 17th ERCOFTAC SIG15/MONACO2025 workshop: Tur-
bulent natural convection flows in differentially heated cavities. Pau, France, 19th Jan. 2023. URL:
https://inria.hal.science/hal-03970569

[18] V. Duffal, R. Manceau and B. de Laage de Meux.
‘Development and Validation of a new
formulation of Hybrid Temporal Large-Eddy Simulation’. In: 17th ERCOFTAC SIG15/MONACO2025
workshop: Turbulent natural convection flows in differentially heated cavities. Pau, France, 19th Jan.
2023. URL: https://inria.hal.science/hal-03972235

[19] J. Jung, I. Lannabi and V. Perrier.
‘On low Mach number fixes for Roe-type schemes’. In:
CEA-SMAI/GAMNI - 35ème Séminaire sur la mécanique des fluides numérique. Paris, France,
23rd Jan. 2023. URL: https://hal.science/hal-04224493

[20] R. Manceau. ‘Modélisation de la turbulence en convection naturelle (conférence introductive)’.
In: Journées thématiques de la SFT. Convection naturelle : aspects fondamentaux et applications.
Orsay, France, 3rd July 2023. URL: https://inria.hal.science/hal-04151728

11.1.4 Leadership within the scientific community

• R. Manceau has been a member of the Standing committee of the Special Interest Group Turbulence
modelling (SIG-15) of ERCOFTAC since 2005, together with 9 other committee members (S. Jakirli´c
[chairman], F. Menter, S. Wallin, D. von Terzi , B. Launder, K. Hanjali´c, W. Rodi, M. Leschziner, D.
Laurence). The main activities of the group is to organize international workshops and thematic
sessions in international congresses.

• Vincent Perrier coordinates the ANR Project LAGOON, a 4-year project started in 2022. The partners

are: the CARDAMOM project-team of Inria Bordeaux and the BRGM.

• Rémi Manceau coordinated the ANR Project MONACO_2025, a 4-year project started in 2018 and

ended in 2023. The partners were: the institute PPrime, PSA Group and EDF.

• Rémi Manceau coordinates the 4-year E2S-UPPA project ASTURIES, which involves CEA and

IFPEN.

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Inria Annual Report 2023

11.1.5 Research administration

• Member of the LMAP council [Rémi Manceau].

• Member of the CDT, in charge of the evaluation of software projects at the Inria Bordeaux center

[Vincent Perrier].

• Elected member of the Inria evaluation committee and member of the board [Vincent Perrier],

Until August 2023. 9. The report of our last four years is available in [38]

• Member of the CT3-Num committee of Pau University, in charge of managing the computing

resources and projects at Pau University [Vincent Perrier].

• Member of the comité des utilisateurs des moyens de calcul at INRIA [Vincent Perrier]

• Member of the scienfic board of INRIA (Since December 2023) [Vincent Perrier]

11.2 Teaching - Supervision - Juries

11.2.1 Teaching

(Legend: L1-L2-L3 corresponds to the 3 years of undergraduate studies, leading to the BSc degree; M1-M2
to the 2 years of graduate studies, leading to the MSc degree; E1-E2-E3 to the 3 years of engineering
school, equivalent to L3-M1-M2, leading to the engineer/MSc degree)

• L1 [J. Jung]: Research and innovation (lectures: 1.5h/year), Université de Pau et des Pays de l’Adour,

Pau, France.

• L1 [J. Jung]: Mathematical Algorithms 1 and Python (lectures: 9h/year) Mathematics, University of

Pau (UPPA).

• L2 [J. Jung]: Numerical analysis for vectorial problems (lectures: 10.5h/year), Mathematics, Uni-

versité de Pau et des Pays de l’Adour, Pau, France.

• L2 [J. Jung]: Scientific computing (labs: 58.5h/year), Informatics, University of Pau (UPPA).

• M1 [J. Jung]: Tools for scientific computing (lectures: 9.75/year, labs: 9h75/year), MMS, Université

de Pau et des Pays de l’Adour, Pau, France.

• M2 [R. Manceau]: Turbulence modelling (in English), 27h30/year, International Master program

Turbulence, ISAE-ENSMA/École centrale de Lille, France.

• E3 [R. Manceau]: Industrial codes for CFD (in English), 12h30/year, ISAE-ENSMA, Poitiers, France

[54].

• E3 [R. Manceau]: Advanced physics–Turbulence modelling for CFD, 16h/year, ENSGTI, France [56].

• E2 [K. Schmidmayer]: Coupled heat transfer, 20h/year, ENSGTI, Pau, France.

• E2 [K. Schmidmayer]: Convective transfer of heat and matter, 16h/year, ENSGTI, Pau, France.

• M1 [K. Schmidmayer]: Introduction to Python, 16h/year, Master MSID, Pau, France.

• L2 [K. Schmidmayer]: Documentary-Communication Project, 4h/year, Master CMI, Pau, France.

• E3 (M. David): Advanced physics (classes: 6h/year, labs: 5h/year) ENSGTI

• E3 (M. David): Modelling and simulation in fluid mechanics (lectures: 4h/year; classes: 16h/year).

ENSGTI.

9https://www.inria.fr/en/inria-evaluation-committee

Project CAGIRE

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• M2 (M. David): Modelling of energy systems CFD for industry using fluent (lectures: 10.5h/year;

classes: 30h/year). UPPA, Master SIMOS.

• L1 (I. Lannabi): Descriptive statistics (22.5h/year, labs), Mathematics & MIASHS. University of Pau

(UPPA).

• L1 (I. Lannabi) Mathematical Algorithms 1 and Python (49.5h/year, labs) Mathematics, University

of Pau (UPPA).

• L2 (A. Bosco) Scientific computing (18h/year labs), computer science, UPPA.

• L1 MIASHS/L2 Natural sciences (A. Bosco) Descriptive statistics (22.5h/year labs), UPPA.

11.2.2 Supervision

• PhD (defended Dec. 2023): Puneeth Bikkanahally Muni Reddy, “Modelling turbulent flows in
natural convection regimes using hybrid RANS-LES approaches”, UPPA, ANR project Monaco_2025,
Rémi Manceau.

• PhD (defended Nov. 2023): Mahitosh Mehta, “Development of an agile methodology for hybrid
RANS-LES computations of turbulent flows”, UPPA, E2S-UPPA Asturies project, Rémi Manceau

• PhD in progress: Romaric Simo Tamou, “Development of high-order methods in a Cartesian
AMR/Cutcell code. Application to LES modelling of combustion”, IFPEN, E2S-UPPA Asturies
project, Vincent Perrier.

• PhD in progress: Anthony Bosco, “Development of Fast, Robust and Accurate numerical methods
for turbulence models on Complex Meshes” CEA/E2S-UPPA, E2S-UPPA Asturies project, Vincent
Perrier and Jonathan Jung.

• PhD in progress: Alexis Ferré, “CFD and experimental study of a thermocline-type thermal storage
for an optimized design and data entry of component scale models in the framework of a multi-scale
approach”, CEA LITEN, Rémi Manceau.

• PhD in progress: Ibtissem Lannabi , “Discontinuous Galerkin methods for low Mach flows in
fluid mechanics”, EDENE project (H2020 Marie-Sklodowska-Curie COFUND), Jonathan Jung and
Vincent Perrier.

• PhD in progress: Esteban Coiffier, "Analyse et simulation numériques de discrétisations décalées

en thermohydraulique diphasique", CEA-Saclay, Vincent Perrier & Jonathan Jung.

• PhD in progress: Jules Mazaleyrat, "Modélisation numérique d’une turbine refroidie par impact
de jets : dérivation de modèles RANS adaptés sur la base d’une approche LES”, SAFRAN HE and
ONERA, Rémi Manceau.

• PhD in progress: Corina Sanz Souhait, “Industrialisation des modèles RANS avancés avec transferts

thermiques pour la convection forcée, mixte et naturelle”, EDF, Rémi Manceau.

11.2.3 Juries

• Reviewer of the PhD thesis of S. Meynet, Normandy university [R. Manceau]

• Reviewer of the PhD thesis of F. Uncu, Sorbonne university [R. Manceau]

• Reviewer of the PhD thesis of M. Djeddou, university of Lorraine [R. Manceau]

• Reviewer of the PhD thesis of P. Seize, Supaero [V. Perrier]

• Reviewer of the PhD thesis of M. Petrella, ETH Zürich [V. Perrier]

• Reviewer of the PhD thesis of J. Bussac, Nantes [V. Perrier]

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Inria Annual Report 2023

• Reviewer of the PhD thesis of G. Jomée, Marseille [V. Perrier]

• Member of the jury of the PhD thesis of M. Stuck, university of Toulouse [R. Manceau]

• Member of the jury of the PhD thesis of M. Mehta, university of Pau [R. Manceau]

• Member of the jury of the PhD thesis of P. Bikkanahally, university of Pau [R. Manceau]

• Member of the jury of the PhD thesis of P. Allegrini, University of Toulouse [V. Perrier]

11.3 Popularization

11.3.1 Education

• P. Bruel supervized a one-week stay of observation of J.-B. Laurouaa, middle school student from

Collège D. Argote (Orthez).

11.3.2 Interventions

[47] K. Schmidmayer. ‘L’accumulation de données, la face cachée de l’intelligence artificielle, vu par
Albert Kahn avec sa documentation du monde en 1920’. In: Journées Européennes du patrimoine
2023. Pau (FRA), France, 16th Sept. 2023. URL: https://hal.science/hal-04209499

[48] K. Schmidmayer. ‘Le double pendule, une représentation du chaos’. In: Villages des Sciences.
Pau, France, 14th Oct. 2023. URL: https://hal.science/hal-04245972

[50] K. Schmidmayer. ‘Modélisation de la mécanique des fluides’. In: 1 scientifique, 1 classe : Chiche
! Lycée Saint John Perse. Pau, France, 5th Dec. 2023. URL: https://hal.science/hal-04325167

[49] K. Schmidmayer. ‘Modélisation de la mécanique des fluides’. In: 1 scientifique, 1 classe :
Chiche ! Lycée Saint John Perse. Pau, France, 12th Dec. 2023. URL: https://hal.science/hal-0
4337844

[51] K. Schmidmayer and J. Cresson. ‘Une introduction aux systèmes chaotiques et bulles de
cavitation’. In: Mathematicum Séminaire de Mathématiques et leurs Applications. Pau, France,
25th Jan. 2023. URL: https://hal.science/hal-03960412

[52] K. Schmidmayer, R. Manceau and J. Jung. ‘Nos futurs : Jumeaux numériques et modèles de
langages’. In: Nuit Européenne des chercheurs. Pau, France, 29th Sept. 2023. URL: https://hal
.science/hal-04225207

• P. Bruel participated in the «Carrefour des Métiers» organized by "La ZAP des Gaves (Académie
de Bordeaux)" on March 30, 2023. He manned a booth during the all day with the objective of
explaining the activity of a researcher to a large audience of middle school students.

12 Scientific production

12.1 Major publications

[1] L. Biasiori-Poulanges and K. Schmidmayer. ‘A phenomenological analysis of droplet shock-
induced cavitation using a multiphase modelling approach’. In: Physics of Fluids 35 (6th Jan.
2023), p. 013312. DOI: 10.1063/5.0127105. URL: https://hal.archives-ouvertes.fr/hal-
03894523.

[2] P. Bruel, S. Delmas, J. Jung and V. Perrier. ‘A low Mach correction able to deal with low Mach
acoustics’. In: Journal of Computational Physics 378 (2019), pp. 723–759. URL: https://hal.inr
ia.fr/hal-01953424.

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[3] S. Dellacherie, J. Jung, P. Omnes and P.-A. Raviart. ‘Construction of modified Godunov type
schemes accurate at any Mach number for the compressible Euler system’. In: Mathematical
Models and Methods in Applied Sciences (Nov. 2016). DOI: 10.1142/S0218202516500603. URL:
https://hal.archives-ouvertes.fr/hal-00776629.

[4] V. Duffal, B. De Laage De Meux and R. Manceau. ‘Development and Validation of a new formu-
lation of Hybrid Temporal Large Eddy Simulation’. In: Flow, Turbulence and Combustion (2021).
DOI: 10.1007/s10494-021-00264-z. URL: https://hal.inria.fr/hal-03206747.

[5]

J.-L. Florenciano and P. Bruel. ‘LES fluid-solid coupled calculations for the assessment of heat
transfer coefficient correlations over multi-perforated walls’. In: Aerospace Science and Technology
53 (2016), p. 13. DOI: 10.1016/j.ast.2016.03.004. URL: https://hal.inria.fr/hal-0135
3952.

[6] E. Franquet and V. Perrier. ‘Runge-Kutta discontinuous Galerkin method for the approximation of
Baer and Nunziato type multiphase models’. In: Journal of Computational Physics 231.11 (Feb.
2012), pp. 4096–4141. DOI: 10.1016/j.jcp.2012.02.002. URL: https://hal.inria.fr/hal-
00684427.

[7]

J.-M. Hérard and J. Jung. ‘An interface condition to compute compressible flows in variable cross
section ducts’. In: Comptes Rendus Mathématiques (Feb. 2016). DOI: 10.1016/j.crma.2015.10
.026. URL: https://hal.inria.fr/hal-01233251.

[8] R. Manceau. ‘Recent progress in the development of the Elliptic Blending Reynolds-stress model’.
In: International Journal of Heat and Fluid Flow (2015), p. 32. DOI: 10.1016/j.ijheatfluidflo
w.2014.09.002. URL: https://inria.hal.science/hal-01092931.

[9] G. Mangeon, S. Benhamadouche, J.-F. Wald and R. Manceau. ‘Extension to various thermal
boundary conditions of the elliptic blending model for the turbulent heat flux and the temperature
variance’. In: Journal of Fluid Mechanics 905.A1 (Dec. 2020), pp. 1–34. DOI: 10.1017/jfm.2020
.683. URL: https://hal.inria.fr/hal-02974557.

[10] Y. Moguen, S. Delmas, V. Perrier, P. Bruel and E. Dick. ‘Godunov-type schemes with an inertia term
for unsteady full Mach number range flow calculations’. In: Journal of Computational Physics 281
(Jan. 2015), p. 35. DOI: 10.1016/j.jcp.2014.10.041. URL: https://hal.inria.fr/hal-010
96422.

12.2 Publications of the year

International journals

[11] L. Biasiori-Poulanges and K. Schmidmayer. ‘A phenomenological analysis of droplet shock-
induced cavitation using a multiphase modelling approach’. In: Physics of Fluids 35 (6th Jan.
2023), p. 013312. DOI: 10.1063/5.0127105. URL: https://hal.science/hal-03894523.

[12] A. Bosco and V. Perrier. ‘Discontinuous Galerkin methods for axisymmetric flows’. In: Computers
and Fluids 270 (15th Feb. 2024), p. 106139. DOI: 10.1016/j.compfluid.2023.106139. URL:
https://inria.hal.science/hal-04356856.

[13] T. Galié, J. Jung, I. Lannabi and V. Perrier. ‘Extension of an all-Mach Roe scheme able to deal with
low Mach acoustics to full Euler system’. In: ESAIM: Proceedings and Surveys (18th July 2023). URL:
https://univ-pau.hal.science/hal-04164990.

[14]

J. Jung and V. Perrier. ‘Long time behavior of finite volume discretization of symmetrizable linear
hyperbolic systems’. In: IMA Journal of Numerical Analysis 43.1 (Jan. 2023), pp. 326–356. DOI:
10.1093/imanum/drab092. URL: https://hal.science/hal-03503847.

[15] M. Mehta, R. Manceau, V. Duffal and B. de Laage de Meux. ‘An active hybrid Reynolds-Averaged
Navier-Stokes/Large Eddy Simulation approach for grey area mitigation’. In: Physics of Fluids 35
(2023). DOI: 10.1063/5.0174381. URL: https://inria.hal.science/hal-04287062.

[16] K. Schmidmayer and L. Biasiori-Poulanges. ‘Geometry effects on the droplet shock-induced
cavitation’. In: Physics of Fluids 35.6 (6th June 2023), p. 063315. DOI: 10.1063/5.0151404. URL:
https://hal.science/hal-04100852.

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Inria Annual Report 2023

Invited conferences

[17] P. Bikkanahally and R. Manceau. ‘Modelling turbulent flows in the natural convection regime using
hybrid RANS-LES approaches’. In: 17th ERCOFTAC SIG15/MONACO2025 workshop: Turbulent
natural convection flows in differentially heated cavities. Pau, France, 19th Jan. 2023. URL: https:
//inria.hal.science/hal-03970569.

[18] V. Duffal, R. Manceau and B. de Laage de Meux. ‘Development and Validation of a new formulation
of Hybrid Temporal Large-Eddy Simulation’. In: 17th ERCOFTAC SIG15/MONACO2025 workshop:
Turbulent natural convection flows in differentially heated cavities. Pau, France, 19th Jan. 2023.
URL: https://inria.hal.science/hal-03972235.

[19]

J. Jung, I. Lannabi and V. Perrier. ‘On low Mach number fixes for Roe-type schemes’. In: CEA-
SMAI/GAMNI - 35ème Séminaire sur la mécanique des fluides numérique. Paris, France, 23rd Jan.
2023. URL: https://hal.science/hal-04224493.

[20] R. Manceau. ‘Modélisation de la turbulence en convection naturelle (conférence introductive)’.
In: Journées thématiques de la SFT. Convection naturelle : aspects fondamentaux et applications.
Orsay, France, 3rd July 2023. URL: https://inria.hal.science/hal-04151728.

International peer-reviewed conferences

[21] M. David, M. Mehta and R. Manceau. ‘Towards self-adaptivity in hybrid RANS/LES based on
physical criteria’. In: THMT 2023 - 10th International Symposium on Turbulence, Heat and Mass
Transfer. Rome, Italy, 11th Sept. 2023. URL: https://hal.science/hal-04210071.

[22] S. Elaskar and P. Bruel. ‘Ecuaciones de Navier-Stokes de hombre pobre applicadas a llamas
premezcladas’. In: Matemática Aplicada, Computacional e Industrial (MACI, ISSN: 2314-3282).
MACI 2023 - IX Congreso de Matemática Aplicada, Computacional e Industrial. Vol. 9. Santa Fe,
Argentina, 8th May 2023. URL: https://inria.hal.science/hal-04186270.

[23] A. Ferre, J. Pouvreau, S. Serra, R. Manceau and A. Bruch. ‘CFD study of thermocline formation
in stratified water storage: Consideration of a second-order Boussinesq approximation to model
buoyancy effects and its application to assess the impact of operating conditions’. In: IHTC-17 |
ID: 435. Proceedings of the 17th International Heat Transfer Conference, IHTC-17 14 – 18 August
2023, Cape Town, South Africa. Cape Town, South Africa, 14th Aug. 2023. URL: https://hal.sci
ence/hal-04145083.

[24] M. Grioni, S. Elaskar, P. Bruel and A. Mirasso. ‘Analysis of the Reynolds stress tensor for unsteady
flows in URANS models’. In: Matemática Aplicada, Computacional e Industrial (MACI, ISSN:
2314-3282). MACI 2023 - IX Congreso de Matemática Aplicada, Computacional e Industrial. Vol. 9
(à paraitre, to appear). Santa Fe, Argentina, 8th May 2023. URL: https://inria.hal.science/h
al-04186964.

[25]

J. Jung, I. Lannabi and V. Perrier. ‘On the convergence of Godunov scheme with a centered
discretization of the pressure gradient’. In: FVCA X 2023 - Finite Volumes for Complex Applications
X. Strasbourg, France, 13th Oct. 2023. URL: https://hal.science/hal-04260535.

[26] M. Mehta and R. Manceau. ‘Grey area mitigation in hybrid RANS/LES by means of volume forcing’.
In: Proc. 10th Int. Symp. Turbulence, Heat and Mass Transfer. THMT 2023 - 10th International
Symposium on Turbulence, Heat and Mass Transfer. Rome, Italy, 11th Sept. 2023. URL: https:
//inria.hal.science/hal-04192339.

[27]

J.-F. Wald, G. Mangeon, S. Benhamadouche, R. Manceau and C. Flageul. ‘Conjugate heat transfer
with different fluid-solid physical properties: a differential flux model based on elliptic blending’.
In: THMT 2023 - 10th International Symposium on Turbulence, Heat and Mass Transfer. Rome,
Italy, 11th Sept. 2023. URL: https://inria.hal.science/hal-04203590.

Conferences without proceedings

[28] A. Bosco, V. Perrier and J. Jung. ‘Variational Formulation of Wall Boundary Conditions of RANS
Models in a Discontinuous Galerkin Framework’. In: CFC 2023 - 22nd Computational Fluids
Conference. Cannes, France, 25th Apr. 2023. URL: https://hal.science/hal-04095353.

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[29]

J. Jung, I. Lannabi and V. Perrier. ‘Link between the low Mach number accuracy problem and the
solution of a wave system’. In: NUMHYP 2023 - Numerical Methods for Hyperbolic Problems.
Bordeaux, France, 26th June 2023. URL: https://hal.science/hal-04224511.

[30] R. Manceau. ‘Comparison of turbulence models for the case of a differentially heated square
cavity’. In: 17th ERCOFTAC SIG15/MONACO2025 workshop: Turbulent natural convection flows
in differentially heated cavities. Pau, France, 19th Jan. 2023. URL: https://inria.hal.science
/hal-03970025.

[31] R. Manceau. ‘Cubic cavity with centrally placed partially heated inner obstacle: evaluation of
the turbulence models’. In: 17th ERCOFTAC SIG15/MONACO2025 workshop: Turbulent natural
convection flows in differentially heated cavities. Pau, France, 19th Jan. 2023. URL: https://inri
a.hal.science/hal-03970046.

[32] R. Manceau. ‘MONACO_2025: Modelling natural convection: A Challenge for the Full Digital 2025
Ambition’. In: 17th ERCOFTAC SIG15/MONACO_2025 workshop: Turbulent natural convection
flows in differentially heated cavities. Pau, France, 19th Jan. 2023. URL: https://inria.hal.sci
ence/hal-03969991.

[33] V. Perrier. ‘Derivation of fully closed two-phase models of Baer-and-Nunziato type’. In: The 11th
International Conference on Multiphase Flow. Kobe, Japan, 2nd Apr. 2023. URL: https://inria
.hal.science/hal-04356823.

[34] K. Schmidmayer. ‘Droplet shock-induced cavitation using a multiphase modelling approach’. In:
LMAP seminar. Pau, France, 5th Jan. 2023. URL: https://hal.science/hal-03924694.

[35] K. Schmidmayer and L. Biasiori-Poulanges. ‘On bubble cloud growth in shock-droplet interaction’.
In: ICMF 2023 - 11th International Conference on Multiphase Flow. Kobe, Japan, 2nd Apr. 2023.
URL: https://hal.science/hal-04086409.

[36] R. Simo-Tamou, J. Bohbot, J. Coatléven, V. Perrier and Q. H. Tran. ‘High order Flux Reconstruction
schemes for turbulent flows and spectral analysis’. In: 10th International Congress on Industrial
and Applied Mathematics (ICIAM 2023). Tokyo, Japan, 20th Aug. 2023. URL: https://hal.scien
ce/hal-04396800.

Reports & preprints

[37] A. Bosco and V. Perrier. Discontinuous Galerkin methods for axisymmetric flows: extended version.
RR-9524. INRIA, 10th Oct. 2023, p. 49. URL: https://inria.hal.science/hal-04236220.

[38] A. Canteaut, M. Serrano, C. Grandmont, G. Pallez, V. Perrier, X. Rival and E. Thomé. Bilan de la
mandature 2019-2023 de la Commission d’Évaluation Inria. Inria, 31st Aug. 2023. URL: https://i
nria.hal.science/hal-04193082.

[39] M. David, M. Mehta and R. Manceau. A self-adaptive strategy for hybrid RANS/LES based on

physical criteria. 16th Jan. 2024. URL: https://hal.science/hal-04396836.

Other scientific publications

[40] E. Coiffier and M. Ndjinga. ‘On a discontinuity capturing Finite Volume method that can solve
fully incompressible flows’. In: Groupe de Travail Mathématiques pour le Nucléaire (GdR MaNu)
2023. Le Croisic, France, 23rd Oct. 2023. URL: https://inria.hal.science/hal-04397889.

[41] E. Coiffier and M. Ndjinga. ‘On a discontinuity capturing Finite Volume method that can solve
fully incompressible flows’. In: SMAI 2023 - Congrès de la Société des Mathématiques Appliquées
et Industrielles. Le Gosier, Guadeloupe, France, 22nd May 2023. URL: https://inria.hal.scie
nce/hal-04397820.

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Inria Annual Report 2023

12.3 Other

Scientific popularization

[42]

[43]

[44]

[45]

[46]

I. Lannabi and J. Cresson. Campus des enfants. 3rd July 2023. URL: https://univ-pau.hal.sci
ence/hal-04397687.

I. Lannabi and J. Cresson. Fête de la science - village des sciences. 14th Oct. 2023. URL: https://un
iv-pau.hal.science/hal-04397717.

I. Lannabi and J. Cresson. Maths en jeans. 31st Mar. 2023. URL: https://univ-pau.hal.scienc
e/hal-04397651.

I. Lannabi and I. Greff. Journée Filles, maths et informatique. 14th Dec. 2023. URL: https://univ-
pau.hal.science/hal-04397753.

I. Lannabi, J. Jung and V. Perrier. ‘Behavior of the compressible Euler equations in the low Mach
number limit’. In: Journées Doctorales de la Fédération MARGAUx 2023. Poitiers (Université de
Poitiers), France, 22nd May 2023. URL: https://univ-pau.hal.science/hal-04397584.

[47] K. Schmidmayer. ‘L’accumulation de données, la face cachée de l’intelligence artificielle, vu par
Albert Kahn avec sa documentation du monde en 1920’. In: Journées Européennes du patrimoine
2023. Pau (FRA), France, 16th Sept. 2023. URL: https://hal.science/hal-04209499.

[48] K. Schmidmayer. ‘Le double pendule, une représentation du chaos’. In: Villages des Sciences. Pau,

France, 14th Oct. 2023. URL: https://hal.science/hal-04245972.

[49] K. Schmidmayer. ‘Modélisation de la mécanique des fluides’. In: 1 scientifique, 1 classe : Chiche !
Lycée Saint John Perse. Pau, France, 12th Dec. 2023. URL: https://hal.science/hal-0433784
4.

[50] K. Schmidmayer. ‘Modélisation de la mécanique des fluides’. In: 1 scientifique, 1 classe : Chiche !
Lycée Saint John Perse. Pau, France, 5th Dec. 2023. URL: https://hal.science/hal-04325167.

[51] K. Schmidmayer and J. Cresson. ‘Une introduction aux systèmes chaotiques et bulles de cavitation’.
In: Mathematicum Séminaire de Mathématiques et leurs Applications. Pau, France, 25th Jan. 2023.
URL: https://hal.science/hal-03960412.

[52] K. Schmidmayer, R. Manceau and J. Jung. ‘Nos futurs : Jumeaux numériques et modèles de
langages’. In: Nuit Européenne des chercheurs. Pau, France, 29th Sept. 2023. URL: https://hal
.science/hal-04225207.

Educational activities

[53] R. Manceau. ‘Codes de calcul industriels pour la simulation des écoulements turbulents’. Master.

France, 5th Feb. 2024. URL: https://inria.hal.science/hal-03207435.

[54] R. Manceau. ‘Industrial codes for CFD’. Master. France, 5th Feb. 2024. URL: https://inria.hal

.science/hal-03207431.

[55] R. Manceau. ‘Modelisation de la turbulence pour la CFD’. Master. France, 19th Oct. 2023. URL:

https://inria.hal.science/hal-03207437.

[56] R. Manceau. ‘Turbulence modelling for CFD’. Master. France, 19th Oct. 2023. URL: https://inr

ia.hal.science/hal-03207433.

12.4 Cited publications

[57] A. Abbà, M. Germano and M. Nini. ‘A RANS assisted LES approach’. In: Direct and Large-Eddy
Simulation XI. Ed. by M. Salvetti, V. Armenio, J. Fröhlich, B. Geurts and H. Kuerten. Vol. 25.
ERCOFTAC Series. Springer, Cham, 2019, pp. 159–165.

[58] A. H. Afailal. ‘Numerical simulation of non-reactive aerodynamics in Internal Combustion Engines
using a hybrid RANS/LES approach’. Theses. Université de Pau et des Pays de l’Adour, Dec. 2020.
URL: https://tel.archives-ouvertes.fr/tel-03140392.

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[59] A. H. Afailal, J. Galpin, A. Velghe and R. Manceau. ‘Development and validation of a hybrid
temporal LES model in the perspective of applications to internal combustion engines’. In: Oil &
Gas Science and Technology - Revue d’IFP Energies nouvelles 74 (2019), p. 56. DOI: 10.2516/ogst
/2019031. URL: https://hal-ifp.archives-ouvertes.fr/hal-02162596.

[60]

J.-A. Bäckar and L. Davidson. ‘Evaluation of numerical wall functions on the axisymmetric
impinging jet using OpenFOAM’. In: Int. J. Heat Fluid Fl. 67 (2017), pp. 27–42.

[61] M. R. Baer and J. W. Nunziato. ‘A two-phase mixture theory for the deflagration-to-detonation
transition (DDT) in reactive granular materials’. In: International journal of multiphase flow 12.6
(1986), pp. 861–889.

[62]

[63]

S. Benhamadouche, R. Howard and R. Manceau, eds. Proc. 15th ERCOFTAC (SIG-15)/IAHR Work-
shop on Refined Turbulence Modelling. EDF Chatou, France. 2011.

S. Benhamadouche, I. Afgan and R. Manceau. ‘Numerical simulations of flow and heat transfer in
a wall-bounded pin matrix’. In: Flow, Turbulence and Combustion 104.1 (2020), pp. 19–44. DOI: 10
.1007/s10494-019-00046-8. URL: https://hal.archives-ouvertes.fr/hal-02179021.

[64] L. Biasiori-Poulanges, C. Bourquard, B. Lukic, L. Broche and O. Supponen. ‘HIFU-induced cavita-
tion bubble cloud dynamics and its role in model kidney stone erosion’. In: Bulletin Am. Phis. Soc.
(2022).

[65] P. Bikkanahally, R. Manceau and F. Mastrippolito. ‘Development of a hybrid RANS-LES model
based on temporal filtering for natural convection flows’. In: WCCM - 14th World Congress in
Computational Mechanics, ECCOMAS Congress 2020. Virtual, France, Jan. 2021. URL: https://ha
l.inria.fr/hal-03114394.

[66] R. Bourguet, M. Braza, G. Harran and R. El Akoury. ‘Anisotropic Organised Eddy Simulation for
the prediction of non-equilibrium turbulent flows around bodies’. In: J. Fluid Struct. 24.8 (2008),
pp. 1240–1251.

[67] C. E. Brennen. ‘Cavitation in medicine’. In: Interface Focus 5.5 (2015), p. 20150022.

[68] D. Bresch and M. Hillairet. ‘A compressible multifluid system with new physical relaxation terms’.

In: Annales Scientifiques de l’École Normale Supérieure 52.2 (2019), pp. 255–295.

[69] P. Bruel, S. Delmas, J. Jung and V. Perrier. ‘A low Mach correction able to deal with low Mach
acoustics’. In: Journal of Computational Physics 378 (Feb. 2019), pp. 723–759. DOI: 10.1016/j.jc
p.2018.11.020. URL: https://hal.inria.fr/hal-01953424.

[70] P. Bruel and P.-D. Nguyen. The ORACLES database. This experimental database hosted by Zenodo
gives access to both the processed and the raw (instantaneous) velocity data measured by 2-
component laser Doppler velocimetry (1-point and 2-point measurements) on the ORACLES test
facility. Aug. 2022. DOI: 10.5281/zenodo.7029888. URL: https://inria.hal.science/hal-
04186197.

[71] B. Chaouat and R. Schiestel. ‘A new partially integrated transport model for subgrid-scale stresses
and dissipation rate for turbulent developing flows’. In: Phys. Fluids 17.065106 (2005), pp. 1–19.

[72] A. Colombié, E. Laroche, F. Chedevergne, R. Manceau, F. Duchaine and L. Gicquel. ‘Large-eddy-
simulation-based analysis of Reynolds-stress budgets for a round impinging jet’. In: Physics of
Fluids 33.11 (Nov. 2021), p. 115109. DOI: 10.1063/5.0064009. URL: https://hal-univ-pau.a
rchives-ouvertes.fr/hal-03423068.

[73] F. Coquel, T. Gallouët, J.-M. Hérard and N. Seguin. ‘Closure laws for a two-fluid two-pressure

model’. In: Comptes Rendus Mathematique 334.10 (2002), pp. 927–932.

[74]

S. Deck. ‘Recent improvements in the Zonal Detached Eddy Simulation (ZDES) formulation’. In:
Theor. Comput. Fluid Dyn. 26.6 (2012), pp. 523–550.

[75] P. Degond and M. Tang. ‘All speed scheme for the low Mach number limit of the isentropic Euler

equations’. In: Communications in Computational Physics 10.1 (2011), pp. 1–31.

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Inria Annual Report 2023

[76] F. Dehoux, S. Benhamadouche and R. Manceau. ‘An elliptic blending differential flux model for
natural, mixed and forced convection’. In: International Journal of Heat and Fluid Flow 63 (2017),
p. 15. DOI: 10.1016/j.ijheatfluidflow.2016.09.003. URL: https://hal.inria.fr/hal-
01391900.

[77] D. A. Drew and S. L. Passman. Theory of multicomponent fluids. Vol. 135. Springer Science &

Business Media, 2006.

[78] V. Duffal. ‘Development of a hybrid RANS-LES model for the prediction of unsteady loads at the
wall’. Theses. Université de Pau et des Pays de l’Adour, Nov. 2020. URL: https://tel.archives-
ouvertes.fr/tel-03038837.

[79] V. Duffal, B. de Laage de Meux and R. Manceau. ‘A new formulation of hybrid temporal large-
eddy simulation’. In: ETMM 2021 - 13th International ERCOFTAC symposium on engineering,
turbulence, modelling and measurements. Rhodes / Virtua, Greece, Sept. 2021. URL: https://hal
.inria.fr/hal-03366796.

[80] V. Duffal, B. de Laage de Meux and R. Manceau. ‘Development and Validation of a new formulation
of Hybrid Temporal Large Eddy Simulation’. In: Flow, Turbulence and Combustion 108 (2022), p. 42.
DOI: 10.1007/s10494-021-00264-z. URL: https://inria.hal.science/hal-03206747.

[81] N. Favrie, K. Schmidmayer and J. Massoni. ‘A multiphase irreversible-compaction model for

granular-porous materials’. In: Continuum Mech. Thermodyn. 34.1 (2022), pp. 217–241.

[82] A. Ferré, R. Manceau, S. Serra, J. Pouvreau and A. Bruch. ‘Etude CFD de l’impact des conditions
d’injection pour un stockage thermocline en eau’. In: SFT 2022 - 30ème Congrès de la Société
Française Thermique SFT. Valenciennes, France, May 2022. URL: https://hal.science/hal-0
3692645.

[83] E. Franquet and V. Perrier. ‘Runge–Kutta discontinuous Galerkin method for the approximation of
Baer and Nunziato type multiphase models’. In: Journal of Computational Physics 231.11 (2012),
pp. 4096–4141.

[84] M. Germano. ‘Properties of the hybrid RANS/LES filter’. In: Theor. Comput. Fluid Dyn. 17.4 (2004),

pp. 225–231.

[85] H. Guillard and C. Viozat. ‘On the behaviour of upwind schemes in the low Mach number limit’.

In: Computers & fluids 28.1 (1999), pp. 63–86.

[86] A. L. Gurson. ‘Continuum theory of ductile rupture by void nucleation and growth: Part I–Yield
criteria and flow rules for porous ductile media’. In: J. Eng. Mater. Technol. 99.1 (1977), pp. 2–15.

[87] M. Hantke, S. Müller and L. Grabowsky. ‘News on Baer–Nunziato-type model at pressure equilib-

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S. M. S. Jameel, R. Manceau and V. Herbert. ‘A buoyancy extension for eddy-viscosity models for
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[91] S. M. S. Jameel, R. Manceau and V. Herbert. ‘Sensitization of eddy-viscosity models to buoyancy
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S. K. Jena, P. Bikkanahally and R. Manceau. ‘Numerical simulation of a turbulent natural convec-
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[94] V. A. Khokhlova, J. B. Fowlkes, W. W. Roberts, G. R. Schade, Z. Xu, T. D. Khokhlova, T. L. Hall, A. D.
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[95] L. E. Kidder, S. E. Field, F. Foucart, E. Schnetter, S. A. Teukolsky, A. Bohn, N. Deppe, P. Diener,
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[96] R. Manceau. ‘Contra-rotating jets: wake/mixing layer interaction’. In: Proc. 10th ERCOFTAC
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[97] R. Manceau. ‘Progress in Hybrid Temporal LES (invited keynote paper)’. In: Papers contributed
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[99] R. Manceau and K. Hanjali´c. ‘Elliptic Blending Model: A New Near-Wall Reynolds-Stress Tur-
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[100] R. Manceau. ‘Modélisation des transferts thermiques turbulents (conférence plénière)’. In: 26e
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[101] R. Manceau. ‘Modelling of turbulent natural convection (keynote lecture)’. In: 16th ERCOFTAC
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[103] G. Mangeon, S. Benhamadouche, J.-F. Wald and R. Manceau. ‘Extension to various thermal
boundary conditions of the elliptic blending model for the turbulent heat flux and the temperature
variance’. In: Journal of Fluid Mechanics 905.A1 (Dec. 2020), pp. 1–34. DOI: 10.1017/jfm.2020
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[104] F. Mastrippolito, R. Manceau and P. Bruel. ‘Modélisation des effets de giration pour les jets en
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J. Mazars and G. Pijaudier-Cabot. ‘Continuum damage theory-application to concrete’. In: J. eng.
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[106] M. Mehta, R. Manceau, V. Duffal and B. de Laage de Meux. ‘An active hybrid RANS/LES approach
for grey area mitigation’. In: DLES13 - Direct and Large Eddy Simulation. Udine, Italy, Oct. 2022.
URL: https://inria.hal.science/hal-03832703.

[107] Y. Moguen, T. Kousksou, P. Bruel, J. Vierendeels and E. Dick. ‘Pressure–velocity coupling allowing
acoustic calculation in low Mach number flow’. In: Journal of Computational Physics 231.16 (2012),
pp. 5522–5541.

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[108] C. Moussaed, S. Wornom, B. Koobus, A. Dervieux, T. Deloze, R. El Akoury, D. Szubert, Y. Hoarau
and M. Braza. ‘VMS and OES-based hybrid simulations of bluff body flows’. In: Notes on Numerical
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S. Ndanou, N. Favrie and S. Gavrilyuk. ‘Multi-solid and multi-fluid diffuse interface model: Applic-
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[110] P. Nguyen, P. Bruel and S. Reichstadt. ‘An experimental database for benchmarking simulations
of turbulent premixed reacting flows: lean extinction limits and velocity field measurements
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[111] V. Perrier and E. Gutiérrez. ‘Derivation and Closure of Baer and Nunziato Type Multiphase Models
by Averaging a Simple Stochastic Model’. In: Multiscale Modeling and Simulation: A SIAM Inter-
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[112] Y. A. Pishchalnikov, W. M. Behnke-Parks, K. Schmidmayer, K. Maeda, T. Colonius, T. W. Kenny and
D. J. Laser. ‘High-speed video microscopy and numerical modeling of bubble dynamics near a
surface of urinary stone’. In: J. Acoust. Soc. Am. 146 (2019), pp. 516–531.

[113] P. Reulet, E. Laroche, D. Donjat, F. Mastrippolito, R. Manceau and P. Bruel. Parametric study of the
effect of gyration on the flow and heat transfer of multiperforated plates. SOPRANO : Soot processes
and radiation in aeronautical innovative combustors. H2020 european project (D3.1). 2021.

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J.-K. Shin, J.-K. Byun and Y.-D. Choi. ‘A low Reynolds number dissipation rate equation model
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[119] G. Sporschill. ‘Improved Reynolds-Stress Modeling for Adverse-Pressure-Gradient Turbulent
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[120] G. Sporschill, F. Billard, M. Mallet and R. Manceau. ‘Reynolds stress RANS models for industrial
aeronautical applications’. In: WCCM-ECCOMAS Congress - 14th World Congress in Computational
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[121] G. Sporschill, F. Billard, M. Mallet and R. Manceau. ‘Turbulence modelling improvements for APG
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<scratchpad>
- Main topic: Research Centre CAGIRE
- Key points:
  - CAGIRE is an interdisciplinary project focused on numerical simulation of turbulent flows
  - The project aims to develop, validate, and promote original and effective approaches for modeling and simulating generic flows
  - Key research areas include turbulence modeling, high-order numerical methods, compressible and multiphase flows, and analysis and simulation of turbulent flows and heat transfer
  - The project has collaborations with various industrial partners and research institutions
- Structure: The document is divided into sections, including project overview, research program, application domains, social and environmental responsibility, new software and platforms, open data, new results, partnerships and cooperations, dissemination, scientific production, and more
- Potential artifacts to ignore: web-related elements, such as links, HTML tags, and unnecessary text
</scratchpad>

<final_summary>
The CAGIRE research centre is an interdisciplinary project focused on numerical simulation of turbulent flows, with a goal of developing, validating, and promoting original and effective approaches for modeling and simulating generic flows. The project has key research areas in turbulence modeling, high-order numerical methods, compressible and multiphase flows, and analysis and simulation of turbulent flows and heat transfer. CAGIRE has collaborations with various industrial partners and research institutions, including CNRS, Université de Pau et des Pays de l'Adour, and EDF. The project aims to improve the reliability of industrial numerical simulations, reduce environmental impact, and enhance safety. Key research areas include turbulence modeling, high-order numerical methods, compressible and multiphase flows, and analysis and simulation of turbulent flows and heat transfer.
The CAGIRE research centre is an interdisciplinary project focused on numerical simulation of turbulent flows, with a goal of developing, validating, and promoting original and effective approaches for modeling and simulating generic flows. The project has key research areas in turbulence modeling, high-order numerical methods, compressible and multiphase flows, and analysis and simulation of turbulent flows and heat transfer. CAGIRE has collaborations with various industrial partners and research institutions, including CNRS, Université de Pau et des Pays de l'Adour, and EDF. The project aims to improve the reliability of industrial numerical simulations, reduce environmental impact, and enhance safety. Key research areas include turbulence modeling, high-order numerical methods, compressible and multiphase flows, and analysis and simulation of turbulent flows and heat transfer.