Recent results – CAGIRE project-team

Publications HAL du labo/EPI cagire

titre: An operational discontinuous Galerkin shallow water model for coastal flood assessment
auteur: Andrea Gilberto Filippini, Luca Arpaia, Vincent Perrier, Rodrigo Pedreros, Philippe Bonneton, D. Lannes, Françoise Marche, Sebastien de Brye, Simon Delmas, Sophie Lecacheux, Faïza Boulahya, Mario Ricchiuto
article: Ocean Modelling, 2024, 192, pp.102447. ⟨10.1016/j.ocemod.2024.102447⟩
resume: Hydrodynamic modeling for coastal flooding risk assessment is a highly relevant topic. Many operational tools available for this purpose use numerical techniques and implementation paradigms that reach their limits when confronted with modern requirements in terms of resolution and performances. In this work, we present a novel operational tool for coastal hazards predictions, currently employed by the BRGM agency (the French Geological Survey) to carry out its flooding hazard exposure studies and coastal risk prevention plans on International and French territories. The model, called UHAINA (wave in the Basque language), is based on an arbitrary high-order discontinuous Galerkin discretization of the nonlinear shallow water equations with SSP Runge–Kutta time stepping on unstructured triangular grids. It is built upon the finite element library AeroSol, which provides a modern C++ software architecture and high scalability, making it suitable for HPC applications. The paper provides a detailed development of the mathematical and numerical framework of the model, focusing on two key-ingredients : (i) a pragmatic treatment of the solution in partially dry cells which guarantees efficiently well-balancedness, positivity and mass conservation at any polynomial order; (ii) an artificial viscosity method based on the physical dissipation of the system of equations providing nonlinear stability for non-smooth solutions. A set of numerical validations on academic benchmarks is performed to highlight the efficiency of these approaches. Finally, UHAINA is applied on a real operational case of study, demonstrating very satisfactory results.
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titre: Modélisation hybride RANS/LES : du formalisme aux applications
auteur: Remi Manceau
article: Atelier sur la représentation des fines échelles océaniques dans les simulations numériques, Oct 2024, Plouzané, France
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titre: Investigating cavitation activity and damage evolution in kidney stone fragmentation through X-ray high-speed imaging and microtomography
auteur: Armand Sieber, Gazendra Shakya, Bratislav Lukić, Guillaume Thomas Bokman, Markus Belau, Moritz Schlötter, Arvid Kühl, Kevin Schmidmayer, Outi Supponen
article: 1st European Fluid Dynamics Conference, EFDC1, Sep 2024, Aachen, Germany
resume: Extracorporeal shock wave lithotripsy (ESWL) is a non-invasive medical procedure used to break up kidney stones into smaller fragments that can then be excreted naturally by the body. The shock wave interaction with the stone is usually followed by the growth of cavitation bubbles around the stone, as illustrated in Figure 1. The collapse of these bubbles is an important mechanism that contributes to the fragmentation of the stone, in addition to the mechanical effects resulting from the shock wave-stone interaction1. However, since the cavitation activity is triggered by the shock wave, it is challenging to isolate the role of the cavitation bubbles or the shock waves in the fragmentation of the stone. Such a distinction could nevertheless be achieved by bridging fluid dynamics and solid mechanics, which would allow a deeper understanding of the mechanisms of stone fragmentation. To achieve this, we performed in-situ (ultra-)high-speed X-ray and visible light imaging of shock wave-stone interactions at the ID19 beamline of the European Synchrotron Radiation Facility, using a medical lithotripter to generate the shock waves. These visualizations were complemented by high-resolution post-impact microtomography to assess the location and progression of damage in 3D. We herein report on the propagation of such damages in both phantoms and real kidney stones, with the aim to relate fracture patterns to the different mechanisms of stone fragmentation.
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titre: Random Telegraphic Signals with Fractal-like Probability Transition Rates
auteur: Sergio Elaskar, Pascal Bruel, Luis Gutiérrez Marcantoni
article: Symmetry, 2024, 16 (9), pp.1175. ⟨10.3390/sym16091175⟩
resume: Many physical processes feature random telegraph signals, e.g., a time signal c(t) that randomly switches between two values over time. The present study focuses on the class of telegraphic processes for which the transition rates are formulated by using fractal-like expressions. By considering various restrictive hypotheses regarding the statistics of the waiting times, the present analysis provides the corresponding expressions of the unconditional and conditional probabilities, the mean waiting times, the mean phase duration, the autocorrelation function and the associated integral time scale, the spectral density, and the mean switching frequency. To assess the relevance of the various hypotheses, synthetically generated signals were constructed and used as references to evaluate the predictive quality of the theoretically derived expressions. The best predictions were obtained by considering that the waiting times probability density functions were Dirac peaks centered on the corresponding mean values.
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titre: Generation of turbulent structures for CELES (continuous embedded LES)
auteur: Remi Manceau, Mahitosh Mehta, Martin David, Puneeth Bikkanahally
article: A turbulence day in celebration of the career of Jean-Paul Bonnet, Institute PPrime, Jun 2024, Poitiers, France
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titre: Discovering the contribution of cavitation damage in kidney stone ablation through X-ray high-speed imaging and microtomography
auteur: Armand Sieber, Gazendra Shakya, Guillaume Thomas Bokman, Markus Belau, Moritz Schlötter, Arvid Kühl, Bratislav Lukić, Kevin Schmidmayer, Outi Supponen
article: 12th International Cavitation Symposium, CAV2024, Jun 2024, Chania Crete, Greece
resume: Extracorporeal shock wave lithotripsy (ESWL) is a non-invasive clinical procedure that is used to break up kidney stones into small fragments that the body can then excrete. When the stone is exposed to the tensile portion of the shock wave, cavitation bubbles form around it. In addition to the impact of the high-amplitude shock wave onto the stone, it is believed that the growth and violent collapse of these bubbles is one of the main mechanisms responsible for the fragmentation of the stone. However, since the onset of cavitation is caused by the shock wave, it is difficult to separate the effects of these two mechanisms in the comminution of kidney stones, and there is still no clear consensus on the exact role of cavitation in this regard. Nevertheless, this separation could be resolved by linking the fluid mechanics of the cavitation activity to the solid mechanics of the stone fragmentation. We propose to accomplish this by in-situ high-speed X-ray imaging of shock wave-stone interactions, complemented by post-impact microtomography of the stone to assess the location and evolution of damages. This paper highlights the challenges associated with this topic, presents the design of an experimental protocol to perform the measurements described above using a medical lithotripter at the European Synchrotron Radiation Facility in February 2024, and shows preliminary results.
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titre: A curl preserving finite volume scheme by space velocity enrichment. Application to the low Mach number accuracy problem
auteur: Jonathan Jung, Vincent Perrier
article: Journal of Computational Physics, 2024, 515, pp.113252. ⟨10.1016/j.jcp.2024.113252⟩
resume: In this article, we address the problem of accuracy of finite volume schemes in the low Mach number limit. It has been known for years that collocated finite volume schemes are naturally correctly behaving in this limit on triangular meshes [20, 21, 15], but fail in general on other types of mesh. We are first interested in the general problem of the conservation of vorticity for the wave system. By enriching the approximation space for vectors, we prove that the Hodge-Helmholtz context developed for triangular meshes in [15] can be recovered in the quadrangular mesh case. This leads to a numerical scheme for the wave system that naturally preserves the vorticity under mild assumption on the numerical flux. The new approximation space is then used with the barotropic Euler system. Numerical tests show that the new numerical scheme is accurate for both steady and acoustic problems at low Mach number.
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titre: Discontinuous Galerkin methods for axisymmetric flows
auteur: Anthony Bosco, Vincent Perrier
article: Computers and Fluids, 2024, 270, pp.106139. ⟨10.1016/j.compfluid.2023.106139⟩
resume: In this article, high order discontinuous Galerkin methods for axisymmetric flows are developed. A first work is performed to put the equations in a so called canonical form to gather terms of similar nature, and also for ensuring the three dimensional conservativity. Then the numerical scheme is developed. Instead of relying on the strong axisymmetric formulation, we rely on the -averaged form of the standard three-dimensional discontinuous Galerkin method for the Navier–Stokes system. This allows to derive a numerical scheme without ambiguity on the source terms. The numerical scheme is new and makes link between different formulations previously proposed. A wide and progressive set of test cases, especially designed for axisymmetric problems is proposed. The numerical scheme is tested using these cases and the optimal order of accuracy is obtained.
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titre: Behavior of the Discontinuous Galerkin Method for Compressible Flows at Low Mach Number on Triangles and Tetrahedrons
auteur: Jonathan Jung, Vincent Perrier
article: SIAM Journal on Scientific Computing, 2024, 46 (1), pp.A452-A482. ⟨10.1137/23M154755X⟩
resume: In this article, we are interested in the behavior of discontinuous Galerkin schemes for compressible flows in the low Mach number limit. We prove that for any numerical flux conserving exactly contacts (e.g., exact Godunov, Roe, HLLC), the numerical scheme is accurate at low Mach number flows on simplicial meshes, which is an extension to higher order of the result proven in [H. Guillard, Comput. Fluids, 38 (2009), pp. 1969–1972]. When the mesh is not simplicial, or when the mesh is simplicial but the numerical flux does not conserve contacts (e.g., Lax-Friedrich, HLL), the scheme is numerically proven to be less accurate in the low Mach number limit.
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titre: Numerical Simulation of Turbulent Flows using the SST-SAS Model
auteur: Mauro Grioni, Sergio Elaskar, Pascal Bruel, Anibal Mirasso
article: WSEAS Transactions on Fluid Mechanics, 2024, 19, pp.24 – 39. ⟨10.37394/232013.2024.19.3⟩
resume: Turbulent flows play a crucial role in various engineering and scientific applications, and the accurate prediction of these flows remains a challenging task. This review explores the application of the Shear Stress Transport Scale-Adaptive Simulation (SST-SAS) turbulence model for solving incompressible turbulent flows, with a specific focus on unsteady wakes behind bluff bodies. Providing a concise overview of the model’s formulation and its advantages, this article highlights the efficacy of the SST-SAS model in simulating the intricate dynamics in different configurations of circular cylinders. The present study affirms that the SST-SAS model can be considered a highly viable alternative for simulating unsteady flows around bluff bodies due to the good predictive quality of the resulting simulations.
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titre: Extension of an all-Mach Roe scheme able to deal with low Mach acoustics to full Euler system
auteur: Thomas Galié, Jonathan Jung, Ibtissem Lannabi, Vincent Perrier
article: ESAIM: Proceedings and Surveys, 2024, 76, pp.35-51. ⟨10.1051/proc/202476035⟩
resume: We propose to extend the fix of Roe’s approximate Riemann solver developed for the Barotropic Euler equations in [2] to the full Euler equations. This scheme is built mainly to handle low Mach acoustic waves. Moreover, compared to pressure-centered type schemes, this numerical fix has the advantage of improving the numerical solution in the sense that the oscillating modes are reduced. The theoretical study is based on a two-time scales asymptotic analysis. It is proved that the Euler system equipped with a general equation of state is consistent with a first-order wave system in a low Mach number regime. Similar analysis is performed at the discrete level on the Roe scheme to derive the new fix. Numerical tests confirm the results obtained for the Barotropic case about the ability of this fix to deal with both steady and low Mach acoustic computations also in the case of full Euler equations.
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titre: On the feasibility of a self-adaptive strategy for hybrid RANS/LES based on physical criteria and its inital testing on low Reynolds number backward-facing step flow
auteur: Martin David, Mahitosh Mehta, Remi Manceau
article: Flow, Turbulence and Combustion, In press
resume: Hybrid RANS/LES methods can produce more reliable results than RANS with a reasonable computational cost. Thus, they have the potential to become the next workhorse in the industry. However, in continuous approaches, whether or not they depend on the grid step explicitly, the ability of the model to switch to a well-resolved LES depends on the mesh generated by the user, such that the results are user-dependent. The present paper proposes a self-adaptive strategy, in which the RANS and LES zones are determined using physical criteria, in order to mitigate the user influence. Starting from an initial RANS computation, successive HTLES are carried out and the mesh is refined according to the criteria. To demonstrate the feasibility of this strategy, the method is applied to the backward-facing step case with the Hybrid Temporal Large Eddy Simulation (HTLES) approach, but is suitable for any other hybrid approach. The results obtained show that the method reaches a fixed point after only a few simulations and significantly improves the predictions when compared to RANS, with no intervention from the user. Even though the process is still a long way from being applicable to a wide range of turbulent flows, this paper is a demonstrator of the applicability of this self-adaptive strategy.
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titre: Dynamics of turbulent natural convection in a cubic cavity with centrally placed partially heated inner obstacle
auteur: Sofen Kumar Jena, Remi Manceau
article: Physics of Fluids, 2024, 38 (8), ⟨10.1063/5.0222258⟩
resume: Natural convection in a cavity with a partially heated obstacle at the centre at the Rayleigh number Ra = 1.46 × 10 9 is investigated using large-eddy simulation (LES). The standard and dynamic Smagorinsky models, as well as the Wall adapting local eddy-viscosity (WALE) model, are used for the sub-grid scales, and the flow statistics are compared with recent experiments. The LES results obtained with different meshes show overall good agreement with the experiments as concerns the flow and heat transfer. Simulation with a non-ideal wall at the adiabatic side of the obstacle is also performed to explain the residual discrepancies observed in the unheated channel. Additional simulations performed with periodic conditions in the spanwise direction are very different from the full three-dimensional (3D) simulations, which demonstrates the significance of 3D effects in the cavity. In particular, periodic simulations show Tollmien-Schlichting kind waves in the transitional region, while the 3D cavity shows an early cross-flow transition to turbulence.
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titre: On the convergence of Godunov scheme with a centered discretization of the pressure gradient
auteur: Jonathan Jung, Ibtissem Lannabi, Vincent Perrier
article: FVCA X 2023 – Finite Volumes for Complex Applications X, Oct 2023, Strasbourg, France
resume: This paper deals with the numerical resolution of a linear wave system using the Godunov scheme with a centered discretization of the pressure gradient. The interest in such schemes is motivated by the low Mach number accuracy problem. We have shown that for both steady and unsteady flows, an oscillatory mode appears in the numerical solution. This can be explained by the loss of the Total Variation Diminishing property on the characteristic variables. Moreover, we have illustrated numerically that the long time numerical solution does not converge to the expected steady state. In addition, the existence of the oscillatory mode in the numerical solution jeopardizes the mesh convergence rate of the scheme.
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titre: Conjugate heat transfer with different fluid-solid physical properties: a differential flux model based on elliptic blending
auteur: Jean-François Wald, Gaëtan Mangeon, Sofiane Benhamadouche, Remi Manceau, Cédric Flageul
article: THMT 2023 – 10th International Symposium on Turbulence, Heat and Mass Transfer, Sep 2023, Rome, Italy. ⟨10.1615/thmt-23.1050⟩
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titre: Towards self-adaptivity in hybrid RANS/LES based on physical criteria
auteur: Martin David, Mahitosh Mehta, Remi Manceau
article: THMT 2023 – 10th International Symposium on Turbulence, Heat and Mass Transfer, ICHMT, Sep 2023, Rome, Italy. ⟨10.1615/thmt-23.520⟩
resume: Hybrid RANS/LES methods can produce more reliable results than RANS with a reasonable computational cost. Thus, they have the potential to become the next workhorse in the industry. However, in continuous approaches, the location of the switching between the RANS and LES modes is based on the mesh and have a significant impact on the results. The present paper aims at developing a self-adaptive strategy based on physical criteria to mitigate the influence of the user’s meshing choices on the results. The method is applied to the backward-facing step with the Hybrid Temporal LES (HTLES) model, but is applicable to any other hybrid approach. Starting from a RANS computation for initialization, successive HTLES are carried out and the mesh is refined according to the criteria. The results obtained show that the method converges and significantly improves the results when compared to RANS, with no intervention from the user. The comparison of the results with the DNS is very encouraging.
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titre: Grey area mitigation in hybrid RANS/LES by means of volume forcing
auteur: Mahitosh Mehta, Remi Manceau
article: THMT 2023 – 10th International Symposium on Turbulence, Heat and Mass Transfer, Sep 2023, Rome, Italy. ⟨10.1615/ichmt.thmt-23.510⟩
resume: The modeled-stress depletion is observed when the fluid flows from a RANS to a LES zone in hybrid modeling due to the dramatic decrease of the modeled stresses and the too slow increase of the resolved stresses. With the aim of developing a general remedy, independent of the type of flow, the present work develops an active approach, which consists in injecting energy in the resolved part to compensate for the loss of energy in the modelled part. Very encouraging results are obtained for channel and periodic hill flows.
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titre: High order Flux Reconstruction schemes for turbulent flows and spectral analysis
auteur: Romaric Simo-Tamou, Julien Bohbot, Julien Coatléven, Vincent Perrier, Quang Huy Tran
article: ICIAM 2023 – 10th International Congress on Industrial and Applied Mathematics, Aug 2023, Tokyo, Japan
resume: This study focuses on evaluating Flux Reconstruction schemes for turbulent flows. For these schemes, we perform new analyses of their dissipation and dispersion properties, and we find consistent results with the classical analysis. Ultimately, we evaluate the effect of the high order and correction functions on the DNS of Taylor-Green vortex. This work provides valuable insights into the performance of FR schemes for turbulent flows and presents a promising new approach for analyzing their stability.
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titre: 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
auteur: Alexis Ferre, Jérôme Pouvreau, Sylvain Serra, Remi Manceau, Arnaud Bruch
article: Proceedings of the 17th International Heat Transfer Conference, IHTC-17 14 – 18 August 2023, Cape Town, South Africa, Aug 2023, Cape Town, South Africa
resume: Thermal storages are components used in energy systems, such as district heating networks or thermal power plants, in order to decouple the supply of heat from its use. Usage rate of monophasic thermocline storages is highly dependent on the thermal gradient zone inside the fluid, also named thermocline. While thermal stratification results of a formation phase followed by a degradation phase, the early stages of thermocline establishment is primarily responsible for its thickness. CFD allow to consider the multiple physical phenomena involved during the thermocline formation, in particular the buoyancy effects. These effects are usually considered by selecting either a variable density with respect to the temperature or a constant one by using the commonly used (first-order) Boussinesq approximation. However, the former approach implies an increased computational cost, and the latter is only valid for an unclear validity range of temperature difference. Hence, this article suggests the use of a second-order Boussinesq approximation, coupled with a RANS turbulence approach, to better account for buoyancy effects in a turbulent water flow submitted to a large temperature differences. CFD results obtained with a quadratic Boussinesq approximation are similar to the one obtained with a variable density but with a computation time reduced by half. This approach is applied to the issue of reducing the thermocline thickness during its creation and the impact of linear flow rate ramps is assessed on both a uniform and initially stratified storage. On an initially cold tank, results show that the longer the ramp time, the thinner the thermocline. In contrast, on the initially stratified tank tested, a gradual injection shows no significant reduction of the thermocline thickness. This can be relevant when performing storage management enhancement.
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titre: Modélisation de la turbulence en convection naturelle (conférence introductive)
auteur: Remi Manceau
article: Journées thématiques de la SFT. Convection naturelle : aspects fondamentaux et applications, Jul 2023, Orsay, France
resume: La modélisation de la turbulence en convection naturelle est un problème à la fois difficile et important au regard des enjeux industriels et environnementaux. La flottabilité couple fortement la dynamique et la thermique et a une influence sur la plupart des termes à modéliser qui est souvent mal connue ou comprise expérimentalement. Si la modélisation au second ordre permet de prendre en compte en partie la subtilité des interactions complexes en jeu, de nombreuses questions restent ouvertes sur les échelles de temps ou la dissipation, par exemple. De nombreuses applications industrielles se basent sur des modèles à viscosité turbulente et corrigent les modèles artificiellement en diminuant le nombre de Prandtl turbulent. Une manière plus physique de procéder consiste à prendre en compte la production par la flottabilité dans la loi de comportement. Ce type de modifications, applicables aux modèles RANS et hybride RANS/LES, permettent d’améliorer la représentation de la physique dans certaines configurations non-stratifiées, mais leur influence reste marginale dans d’autre configurations. Un des problèmes non-résolus est la cohabitation de régions laminaires et turbulentes, la transition dans les couches limites en convection naturelle restant globalement un sujet complètement ouvert en modélisation.
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titre: Link between the low Mach number accuracy problem and the solution of a wave system
auteur: Jonathan Jung, Ibtissem Lannabi, Vincent Perrier
article: NUMHYP 2023 – Numerical Methods for Hyperbolic Problems, Jun 2023, Bordeaux, France
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titre: Geometry effects on the droplet shock-induced cavitation
auteur: Kevin Schmidmayer, Luc Biasiori-Poulanges
article: Physics of Fluids, 2023, 35 (6), pp.063315. ⟨10.1063/5.0151404⟩
resume: Assessment of geometry effects affecting shock-induced cavitation within a droplet is investigated for the first time. To do this, we use a thermodynamically well-posed multiphase numerical model accounting for phase compression and expansion, which relies on a finite pressure-relaxation rate formulation and which allow for heterogeneous nucleation. These geometry effects include the shape of the transmitted wave front, which is related to the shock speed to droplet sound speed ratio, and the droplet geometry (cylindrical versus spherical). Phenomenological differences between the column and the droplet configurations are presented. In addition, the critical Mach number for cavitation appearance is determined for both cases: between M = 1.8 and M = 2 for the column, and between M = 2 and M = 2.2 for the droplet. Based on the transmitted wavefront geometry, with Mach number varying from 1.6 to 6, two cavitation regimes have been identified and the transition has been characterised: an exponentially (M < 4.38) and a linearly (M > 4.38) increasing bubble-cloud volume. On more applied aspects, we also investigate the influence of the bubble cloud on the interface disruption and compare the results against the pure liquid droplet test case. A parallel with the technique of effervescent atomization is eventually presented.
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titre: Analysis of the Reynolds stress tensor for unsteady flows in URANS models
auteur: Mauro Grioni, Sergio Elaskar, Pascal Bruel, Anibal Mirasso
article: MACI 2023 – IX Congreso de Matemática Aplicada, Computacional e Industrial, IMAL; CIMEC; Sinc(i); Dpto. de Matemática, UNL.; AR-SIAM; ASAMACI, May 2023, Santa Fe, Argentina
resume: The present work analyzes the Reynolds stress tensor for unsteady URANS models through the use of the triple decomposition of the instantaneous velocity field. To that end, we assessed the performance of two turbulence models, the SST and SST-SAS, in the turbulent flow over a 3D tube bundle as a test case. Our simulation results are compared with available results using RSM models taken from the literature. It was found that a substantial amount of the resolved motion contributes to the total velocity correlations. The SST-SAS model featured a remarkably greater contribution of the resolved part over the modeled part in comparison with the other URANS models.
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titre: Ecuaciones de Navier-Stokes de hombre pobre applicadas a llamas premezcladas
auteur: Sergio Elaskar, Pascal Bruel
article: MACI 2023 – IX Congreso de Matemática Aplicada, Computacional e Industrial, IMAL; CIMEC; Sinc(i); Dpto. de Matematica, UNL.; AR-SIAM; ASAMACI, May 2023, Santa Fe, Argentina
resume: Se deducen las ecuaciones de Navier-Stokes de hombre pobre para llamas premezcladas usando un modelo fisico basado en las ecuaciones de conservacion de masa, cantidad de movimiento y de una variable que mide el progreso de la combustion. Para obtener estas ecuaciones, se asume una representacion de Fourier de las variables y luego se implementa el procedimiento de Galerkin. El resultado es un sistema dinamico discreto en 4D.
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titre: Variational Formulation of Wall Boundary Conditions of RANS Models in a Discontinuous Galerkin Framework
auteur: Anthony Bosco, Vincent Perrier, Jonathan Jung
article: CFC 2023 – 22nd Computational Fluids Conference, IACM, Apr 2023, Cannes, France
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titre: Derivation of fully closed two-phase models of Baer-and-Nunziato type
auteur: Vincent Perrier
article: The 11th International Conference on Multiphase Flow, Apr 2023, Kobe, Japan
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titre: On bubble cloud growth in shock-droplet interaction
auteur: Kevin Schmidmayer, Luc Biasiori-Poulanges
article: ICMF 2023 – 11th International Conference on Multiphase Flow, Apr 2023, Kobe, Japan
resume: Investigations of shock-induced cavitation is highly challenged by the multiphase nature of the mechanisms involved. Thermodynamically well-posed multiphase numerical models accouting for phase compression and expansion however allow to elucidate the underlying physics. A description of the bubble cloud growth and its effects on the early droplet dynamics is proposed, as well as a critical discussion on the analytical predictions of the cavitation event previously reported.
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titre: On low Mach number fixes for Roe-type schemes
auteur: Jonathan Jung, Ibtissem Lannabi, Vincent Perrier
article: CEA-SMAI/GAMNI – 35ème Séminaire sur la mécanique des fluides numérique, Jan 2023, Paris, France
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titre: Comparison of turbulence models for the case of a differentially heated square cavity
auteur: Remi Manceau
article: 17th ERCOFTAC SIG15/MONACO2025 workshop: Turbulent natural convection flows in differentially heated cavities, Jan 2023, Pau, France
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titre: Modelling turbulent flows in the natural convection regime using hybrid RANS-LES approaches
auteur: Puneeth Bikkanahally, Remi Manceau
article: 17th ERCOFTAC SIG15/MONACO2025 workshop: Turbulent natural convection flows in differentially heated cavities, Jan 2023, Pau, France
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titre: Development and Validation of a new formulation of Hybrid Temporal Large-Eddy Simulation
auteur: Vladimir Duffal, Remi Manceau, Benoit de Laage de Meux
article: 17th ERCOFTAC SIG15/MONACO2025 workshop: Turbulent natural convection flows in differentially heated cavities, Jan 2023, Pau, France
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titre: MONACO_2025: Modelling natural convection: A Challenge for the Full Digital 2025 Ambition
auteur: Remi Manceau
article: 17th ERCOFTAC SIG15/MONACO_2025 workshop: Turbulent natural convection flows in differentially heated cavities, Jan 2023, Pau, France
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titre: Cubic cavity with centrally placed partially heated inner obstacle: evaluation of the turbulence models
auteur: Remi Manceau
article: 17th ERCOFTAC SIG15/MONACO2025 workshop: Turbulent natural convection flows in differentially heated cavities, Jan 2023, Pau, France
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titre: A phenomenological analysis of droplet shock-induced cavitation using a multiphase modelling approach
auteur: Luc Biasiori-Poulanges, Kevin Schmidmayer
article: Physics of Fluids, 2023, 35, pp.013312. ⟨10.1063/5.0127105⟩
resume: Investigations of shock-induced cavitation within a droplet is highly challenged by the multiphase nature of the mechanisms involved. Within the context of heterogeneous nucleation, we introduce a thermodynamically well-posed multiphase numerical model accounting for phase compression and expansion, which relies on a finite pressure-relaxation rate formulation. We simulate (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 is done by comparing the numerical results with the Keller-Miksis model, and the corresponding experiments of Sembian et al. and Field, Dear, and Ogren, respectively. For the latter two, the pressure-relaxation rate is found to be µ = 3.5 and µ = 0.5, respectively. Upon validation of the determined pressure-relaxation rate, we run parametric simulations to elucidate the critical Mach number from which cavitation is likely to occur. Complementing simulations with a geometrical acoustic model, we provide 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, is eventually modified to account for the expansion wave magnitude.
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titre: Droplet shock-induced cavitation using a multiphase modelling approach
auteur: Kevin Schmidmayer
article: LMAP seminar, Jan 2023, Pau, France
resume: Investigations of shock-induced cavitation within a droplet is highly challenged by the multiphase nature of the mechanisms involved. Within the context of heterogeneous nucleation, we introduce a thermodynamically well-posed multiphase numerical model accounting for phase compression and expansion, which relies on a finite pressure-relaxation rate formulation. We simulate the interaction of a cylindrical water droplet with a planar shock wave, and the high-speed impact of a gelatin droplet onto a solid surface. The determination of the finite pressure-relaxation rate is done by comparing the numerical results with the corresponding experiments of Sembian et al. (2016) and Field et al. (1989), respectively. Upon validation of the determined pressure-relaxation rate, we run parametric simulations to elucidate the critical Mach number from which cavitation is likely to occur. Complementing simulations with a geometrical acoustic model, we provide a phenomenological description of the shockinduced cavitation within a droplet, as well as a discussion on the bubble-cloud growth effect on the droplet flow field. The modelling used is implemented in the open-source software ECOGEN which will be briefly presented.
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titre: Long time behavior of finite volume discretization of symmetrizable linear hyperbolic systems
auteur: Jonathan Jung, Vincent Perrier
article: IMA Journal of Numerical Analysis, 2023, 43 (1), pp.326-356. ⟨10.1093/imanum/drab092⟩
resume: This article is dedicated to the long time behavior of a finite volume approximation of general symmetrizable linear hyperbolic system on a bounded domain. In the continuous case this problem is very difficult, and the $\omega $–limit set (namely the set of all the possible long time limits) may be large and complicated to depict if no dissipation is introduced. In this article we prove that in general, with a stable finite volume scheme, the discrete solution converges to a steady state when the time goes to infinity. This property is a direct consequence of the numerical dissipation mechanisms used for stabilizing the discretization. We apply this result for determining the long time limit for several stabilizations of the wave system, and perform a formal link with the low Mach number problem of the nonlinear Euler system. Numerical experiments with the wave system are performed for confirming the theoretical results obtained.
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titre: An active hybrid Reynolds-Averaged Navier-Stokes/Large Eddy Simulation approach for grey area mitigation
auteur: Mahitosh Mehta, Remi Manceau, Vladimir Duffal, Benoit de Laage de Meux
article: Physics of Fluids, 2023, 35, ⟨10.1063/5.0174381⟩
resume: During the transition from the RANS (Reynolds-Averaged Navier-Stokes) mode to the LES (Large Eddy Simulation) mode, i.e., in the so-called grey area, continuous hybrid RANS/LES approaches suffer from the well-known problem of excessively slow generation of resolved structures. Indeed, when the mesh is refined in the direction of the flow, the model is designed to reduce the modeled energy, but there is no mechanism to transfer the equivalent amount of energy into the resolved motion. Hence, the total turbulent energy and turbulent stresses are underestimated, which strongly affects the prediction of the mean flow. This also constitutes a violation of the conservation of mechanical energy, which can only be corrected by an active approach, i.e., an approach that allows the injection of resolved energy. The aim of this work is to develop such an active approach based on the introduction of a fluctuating volume force into the resolved momentum equation, similar to the anisotropic linear forcing (ALF) method proposed previously. The major difference with ALF is that the new method does not require target statistics obtained by a RANS computation, but is based on a simple analysis of the rate of energy transfer related to variations in resolution, enabling the forcing to be extended to continuous hybrid RANS/LES. Application of the new method to the cases of a channel with or without periodic constriction shows a drastic improvement over the case without forcing. Although the method is applied herein to a particular hybrid RANS/LES approach (HTLES, hybrid temporal LES), it can easily be extended to any other approach, as long as a parameter identifies variations in resolution, and thus offers vast application prospects.
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titre: Droplet shock-induced cavitation using a multiphase modelling approach
auteur: Kevin Schmidmayer
article: Sorbonne University Seminar, Pierre and Marie Curie Campus, Institut Jean le Rond d’Alembert, Dec 2022, Paris, France
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titre: Méthodes numérique d’ordre élevé pour la turbulence.
auteur: Anthony Bosco, Vincent Perrier
article: Journée du LRC Anabase avec MARGAUx, Dec 2022, Talence, France
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titre: Numerical simulation of a turbulent natural convection flow in a cubic cavity with centrally placed partially heated inner obstacle
auteur: Sofen Kumar Jena, Puneeth Bikkanahally, Remi Manceau
article: 3rd high-fidelity industrial LES/DNS symp. (HiFiLeD), Dec 2022, Brussels, Belgium
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titre: An active hybrid RANS/LES approach for grey area mitigation
auteur: Mahitosh Mehta, Remi Manceau, Vladimir Duffal, Benoit de Laage de Meux
article: DLES13 – Direct and Large Eddy Simulation, Oct 2022, Udine, Italy
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titre: Modélisation des effets de giration pour les jets en écoulement transverse
auteur: Franck Mastrippolito, Remi Manceau, Pascal Bruel
article: Journée thématique SFT : Aérothermique des systèmes propulsifs pour l’aéronautique, Oct 2022, Paris, France
resume: Représenter l’influence de l’angle de giration entre les jets débouchant et la couche limite incidente est un défi pour la modélisation RANS de la turbulence. Le développement de méthodes basées sur la modélisation au second ordre (EB-RSM) est présenté et les résultats comparés aux données expérimentales. Des résultats préliminaires utilisant une méthode hybride RANS/LES (HTLES) sont également présentés.
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titre: Comparación de algoritmos de acoplamiento velocidad-presión para problemás no estacionarios del flujo alrededor de un cilindro circular
auteur: Mauro Grioni, Sergio Elaskar, Pascal Bruel, Anibal Mirasso
article: ARGENCON 2022 – IEEE Biennial Congress of Argentina, Sep 2022, San Juan, Argentina. pp.1-8, ⟨10.1109/ARGENCON55245.2022.9939984⟩
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titre: Modeling and simulation of bubble dynamics in the diffuse-interface framework
auteur: Kevin Schmidmayer
article: ETH Zürich seminar, Aug 2022, Zürich, Switzerland
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titre: Modelling interactions of waves with diffused interfaces
auteur: Kevin Schmidmayer, Joris Cazé, Fabien Petitpas, Eric Daniel, Nicolas Favrie
article: MultiMat 2022 – 10th International Conference on Numerical Methods for Multi-Material Fluid Flow, Aug 2022, Zürich, Switzerland
resume: When simulating multiphase compressible flows using the diffuse-interface methods, the test cases presented in the literature to validate the modellings with regard to interface problems are always textbook cases: interfaces are sharp and the simulations therefore easily converge to the exact solutions. In real problems, it is rather different because the waves encounter moving interfaces which consequently have already undergone the effects of numerical diffusion. Numerical solutions resulting from the interactions of waves with diffused interfaces have never been precisely investigated and for good reasons, the results obtained are extremely dependent on the model used. Precisely, well-posed models, such as the model of Kapila et al. [1], present similar and important issues when such an interaction occurs, coming from the appearance of a wave-trapping phenomenon. To circumvent those issues, we propose to use a thermodynamically-consistent pressure-disequilibrium model [2] with finite, instead of infinite, pressure-relaxation rate to overcome the difficulties inherent in the computation of these interactions. Because the original method to solve this model only enables infinite relaxation, we propose a new numerical method allowing infinite as well as finite relaxation rates. Solutions of the new modelling are examined and compared to literature, in particular we propose the study of a shock on a water-air interface, but also for problems of helium-air and water-air shock tubes, spherical and non-spherical bubble collapses.
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titre: A multiscale numerical scheme for the simulation of dispersed multiphase flows
auteur: Vincent Perrier, Kevin Schmidmayer
article: MultiMat 2022 – 10th International Conference on Numerical Methods for Multi-Material Fluid Flow, Aug 2022, Zürich, Switzerland
resume: The aim of this talk is to derive both a model and a numerical scheme for the approximation of multiphase models of Baer & Nunziato types[2, 7]. Such models are averaged models, able to both model interface flows and well mixed flows. They can be obtained by averaging Euler models following ideas developed in [3]. A new averaging method was developed in [5], based on an explicit stochastic model. We will show that the multiscale model obtained contains several known models in some limits (e.g. nonconservative and relaxation terms of [7, 5]), and also that it ensures in general all phasic entropy inequalities. Then, we will also show that the same method can be applied at the discrete level for deriving a numerical scheme, based on the ideas of [1, 4]. This numerical scheme will be proven to ensure also positivity and all the entropy inequalities under CFL conditions that can be explicitly derived. As the model, the numerical scheme is multiscale in the sense that it depends on a parameter modeling the local topology of the flow. Last, a simple model for the topological parameter will be discretized, and numerical results with this micro-macro model will be presented.
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titre: Steady low Mach number flows: identification of the spurious mode and filtering method
auteur: Jonathan Jung, Vincent Perrier
article: Journal of Computational Physics, 2022, pp.111462. ⟨10.1016/j.jcp.2022.111462⟩
resume: The aim of this article is to thoroughly identify the spurious mode that jeopardizes the convergence of usual upwind numerical schemes for compressible flows when the Mach number goes to 0. We show that this spurious mode is the long time limit of a wave system whose properties and discretization depend on the scheme used for the compressible system. Once this spurious mode is identified, a filtering method is developed for removing it from the solution of stationary low Mach number compressible flow. Numerical results confirm that at the price of the computation of a long time solution of the wave system, the accuracy of an inaccurate solution of a low Mach number compressible flow can be greatly improved by this filtering method
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titre: On low Mach number fixes for Roe-type schemes
auteur: Jonathan Jung, Vincent Perrier, Ibtissem Lannabi
article: Rencontres de la thermohydraulique numérique du CEA/STMF, Jun 2022, Saint-Rémy-lès-Chevreuse, France
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titre: Relations between the low Mach number problem and the long time limit of the wave system
auteur: Jonathan Jung, Vincent Perrier
article: Rencontres de la thermohydraulique numérique du CEA/STMF, Jun 2022, Saint-Rémy-lès-Chevreuse, France
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titre: Design And Analysis Of Task-based Parallelization Of A Discontinuous Galerkin Euler Flow Solver On Heterogeneous Architectures
auteur: Sangeeth Simon, Vincent Perrier, Jonathan Jung, Matthieu Haefele
article: ECCOMAS 2022 – 8th European Congress on Computational Methods in Applied Sciences and Engineering, Jun 2022, Oslo, Norway
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titre: Discontinuous Galerkin method for the computation of axisymmetric flows
auteur: Anthony Bosco, Vincent Perrier, Jonathan Jung
article: ECCOMAS 2022 – 8th European Congress on Computational Methods in Applied Sciences and Engineering, Jun 2022, Oslo, Norway
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titre: Derivation of models and numerical methods for homogenized multiphase flows based on stochastic ideas
auteur: Vincent Perrier
article: ECCOMAS 2022 – 8th European Congress on Computational Methods in Applied Sciences and Engineering, Jun 2022, Oslo, Norway
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titre: Etude CFD de l’impact des conditions d’injection pour un stockage thermocline en eau
auteur: Alexis Ferré, Remi Manceau, Sylvain Serra, Jérôme Pouvreau, Arnaud Bruch
article: SFT 2022 – 30ème Congrès de la Société Française Thermique SFT, May 2022, Valenciennes, France. ⟨10.25855/T2022-046⟩
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titre: Modeling and simulation of bubble dynamics in the diffuse-interface framework
auteur: Kevin Schmidmayer
article: Workshop on Cavitation, bubble dynamics and mass transfer, May 2022, Strasbourg, France
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titre: A task-based parallelization of a finite volume code for hyperbolic conservation law
auteur: Sangeeth Simon, Vincent Perrier, Jonathan Jung, Matthieu Haefele
article: ParCFD 2022 – 33rd parallel CFD International conference, May 2022, Alba, Italy
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titre: Discontinuous Galerkin method for the simulation of axisymmetric compressible flows
auteur: Anthony Bosco, Vincent Perrier
article: HONOM 2022 – European Workshop on High order nonlinear numerical methods for evolutionary PDEs: Theory and Applications, Apr 2022, Braga, Portugal
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titre: Relations between the low Mach number problem and the long time limit of the wave system
auteur: Jonathan Jung, Vincent Perrier
article: HONOM 2022 – European Workshop on High order nonlinear numerical methods for evolutionary PDEs: Theory and Applications, Apr 2022, Braga, Portugal
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titre: Stochastic derivation of models and numerical methods for multiphase compressible flows
auteur: Vincent Perrier
article: 34ème Séminaire sur la mécanique des fluides numérique, Jan 2022, Paris, France
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titre: An application of the scale-adapted simulation to the unsteady flow across a tube bundle
auteur: Mauro Grioni, Pascal Bruel, Sergio A Elaskar, Anibal E Mirasso
article: International Journal of Heat and Fluid Flow, 2022, 96, pp.109007. ⟨10.1016/j.ijheatfluidflow.2022.109007⟩
resume: In the last decades, one of the main objectives pursued in the field of computational fluid dynamics has been the development of turbulent flow models and simulations techniques capable of generating predictions of flow patterns accurate enough to many industrial applications in a reasonable wall-clock time and at an acceptable cost. Very often, a trade-off has to be sought between the engineer’s expectations regarding the accuracy of the model and the limited computational resources available. In that framework, the present contribution aims at demonstrating the capabilities of the SST-SAS approach which is considered as an intermediate model with respect to accuracy and computational requirements. To that end, the turbulent flow through a tube bundle was selected as test case. Preliminary sensitivity analyses were carried out to properly choose the residuals tolerance level, duration of the physical time integration, mesh size and time step value. The SST-SAS results are compared with available experimental data as well as with different simulations results taken from the literature. A quantitative scoring criterion was defined to sort out the different models results: the SST-SAS ranked first.
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titre: Assessment of Reynolds-Stress models for aeronautical applications
auteur: Gustave Sporschill, Flavien Billard, Michel Mallet, Remi Manceau, Hervé Bézard
article: International Journal of Heat and Fluid Flow, 2022, 96, ⟨10.1016/j.ijheatfluidflow.2022.108955⟩
resume: Three Reynolds-Stress Models (RSMs) have been benchmarked on industrial configurations with aeronautical applications. The models are first compared on a zero-pressure-gradient boundary layer, which highlights the differences in the near-wall approaches of the models. Results are then analyzed for the Skåre & Krogstad adverse-pressure-gradient boundary layer and the Common Research Model (CRM) aircraft for two Reynolds numbers. Both cases display improvements in using RSMs over the eddy-viscosity Spalart-Allmaras model. Two of the considered second-moment closures better predict the boundary layer growth and its shape factor in the Skåre & Krogstad test case, and all noticeably improve the drag-due-to-lift in the CRM case.
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titre: Development and Validation of a new formulation of Hybrid Temporal Large Eddy Simulation
auteur: Vladimir Duffal, Benoît de Laage de Meux, Remi Manceau
article: Flow, Turbulence and Combustion, 2022, 108, pp.42. ⟨10.1007/s10494-021-00264-z⟩
resume: Hybrid RANS-LES approaches have aroused interest for years since they provide unsteady information at a reduced numerical cost compared to LES. In the hybrid context, the use of temporal filtering, to control the energy partition between resolved and modeled scales, ensures a consistent bridging between RANS and LES models. In this regard, a new formulation of Hybrid Temporal Large Eddy Simulation (HTLES) is developed, aiming at improving the theoretical foundation of the model associated with an eddy-viscosity closure. The analytical development is performed, applying the Hybrid-Equivalence criterion, and the model is calibrated in decaying isotropic turbulence. In addition, an upgraded version of the approach is proposed to improve the behavior of the model in near-wall regions, introducing a two-fold shielding function and an internal consistency constraint to provide a suitable control of the RANS-to-LES transition. Applying HTLES to the k-w-SST model, the validation process is carried out on channel and periodic-hill flows, over a range of grids and Reynolds numbers. The predictive accuracy and the robustness to grid coarsening are assessed in these cases, ensuring that HTLES offers a cost-saving alternative to LES.
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