About
132
Publications
13,876
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
2,292
Citations
Introduction
Current institution
Additional affiliations
October 1988 - July 1989
October 1989 - present
Publications
Publications (132)
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 statistic...
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 un...
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 a...
Resumen: Se deducen las ecuaciones de Navier-Stokes de hombre pobre para llamas premezcladas usando un modelo físico basado en las ecuaciones de conservación de masa, cantidad de movimiento y de una variable que mide el progreso de la combustión. Para obtener estas ecuaciones, se asume una representación de Fourier de las variables y luego se imple...
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...
Palabras clave: ondas de choque, Sedov, OpenFOAM, explosión.
Resumen. La rápida liberación de energía asociada a procesos explosivos produce ondas de choque in-tensas (blast waves). En este trabajo se explora las capacidades del software de libre distribución Open-FOAM, mediante el solver rhoCentralFoam, para el modelado de dichos procesos usando...
Palabras clave: RANS, CFD, tanques, viento. Resumen. Uno de los problemas estructurales detectados en tanques de almacenamiento de combustible es la falla por pandeo debido a cargas de viento. La adecuada estimación de estas cargas es importante para la evaluación de la integridad estructural de los mismos. En este contexto, se presenta un estudio...
This study focuses on the numerical simulations of the flow around two tandem cylinders placed near a wall. The cylinders are immersed in a flow with a boundary layer profile at a subcritical Reynolds number (Re=10000). The three-dimensional transient turbulent flow around the cylinders is simulated numerically using the Scale-Adaptive Simulation (...
The interaction of a 3D supersonic turbulent gas flow with a transverse sonic jet injected from the wall has been studied in detail both numerically and experimentally. However, the main drawback of such studies is the lack of detailed description of formation and propagation of vortex structures for moderate and large parameters n (ratio of pressu...
Un algorithme de correction de pression pour les écoulements compressibles est présenté. Il est approprié pour la simulation d’écoulements à tous niveaux du nombre de Mach, pour des solutions présentant des variations régulières ou non, en assurant une représentation précise du transport convectif et de la
propagation acoustique. La discrétisation...
A pressure-correction algorithm is presented for compressible fluid flow regimes. It is well-suited to simulate flows at all levels of Mach number with smooth and discontinuous flow field changes, by providing a precise representation of convective transport and acoustic propagation. The co-located finite volume space discretization is used with th...
The interaction of the spatial supersonic turbulent gas flow with a sound jet injected perpendicularly was widely studied both numerically and experimentally. However, there are only a few studies of the detail analysis of the formation and distribution of vortex structures from moderate till high pressure ratio (the ratio of pressure in the jet to...
This article deals with acoustic computations in low Mach number flows with density based solvers. For ensuring a good resolution of the low Mach number base flow, a scheme able to deal with stationary low Mach number flows is necessary. Previously proposed low Mach number fixes are tested with acoustic computations. Numerical results prove that th...
The integration of phase change materials (PCMs) in buildings especially in their walls is the subject of more than a decade of growing interest due to their potentialities for energy saving and enhancement of thermal comfort. The present investigation concerns the applications related to thermal insulation. The idealized composite wall considered...
The present study is devoted to the assessment of several heat transfer coefficient correlations applied to multi-perforated walls used in aeronautical combustors. The conjugate heat-transfer problem was solved through the coupling of the thermal code AVTP for the solid wall and the large-eddy simulation solver AVBP for the flow evolution. This num...
A three-dimensional supersonic turbulent flow with symmetric normal injection of circularjets from the channel walls is numerically simulated. The initial Favre-averaged Navier–Stokesequations closed by the k–ω turbulence model are solved by an algorithm based on an ENO scheme.The mechanism of the formation of vortical structures due to the interac...
Nous nous intéressons à l'hydrodynamique d'une nappe liquide verticale qui se forme à la sortie d'un convergent de section rectangulaire. L'application visée concerne le procédé d'encollage de feuilles de papier ou de bois employées pour la fabrication de panneaux composites. Afin d'obtenir un encollage régulier et uniforme, il est en effet nécessa...
Momentum interpolation methods allow to properly calculate continuous acoustic waves in low Mach number flows. However, they may fail for acoustic signals with jumps, even if, at high Mach number, their capability is demonstrated for steady flows with shocks and rarefaction fans and for flows with moving shocks, rarefaction waves and contact discon...
The integration of phase change materials (PCMs) in buildings especially in the walls is the subject of more than a decade of growing interest due to their potentialities for energy saving and enhancement of thermal comfort. The present investigation concerns the applications related to thermal insulation. The composite wall studied here by numeric...
Abstract When dealing with high-pressure releases, be it needed by some operating conditions or due to an emergency protocol or even to the occurrence of an accident, one has to consider the relevant risks associated to this leakage. Indeed, in addition to the mechanical and blast effects, the dispersion of the released fluid is of primary importan...
This paper presents a review of the available technologies to provide cooling from solar energy for both thermal and photovoltaic ways. Several multi-criteria performance indicators figuring in the literature are presented followed by a pros and cons analysis of the different solar thermal cooling processes. A market study is also carried out to ev...
An inertia term is introduced in the AUSM + -up scheme. The resulting scheme, called AUSM-IT (IT for Inertia Term), is designed as an extension of the AUSM + -up scheme allowing for full Mach number range calculations of unsteady flows including acoustic features. In line with the continuous asymptotic analysis, the AUSM-IT scheme satisfies the con...
A Rhie-Chow based algorithm for quasi 1-D sound propagation in a low Mach
number mean flow is described. It is shown that the proposed Rhie-Chow interpolation method
preserves the linear wave equation at first order, giving confidence in its ability to properly
simulate flows that feature simultaneously acoustic waves and low Mach number convection...
Inertia term is introduced in a Godunov-type scheme such as to mimic its presence in the Rhie-Chow-like momentum interpolation scheme. The resulting scheme, termed AUSM-IT, is defined as an extension of the AUSM+ -up scheme by [Liou, J. Comput. Phys., 2006], which is retrieved when the Mach number is larger than unity. Thus, the AUSM-IT scheme inhe...
L'intégration de matériaux à changement de phase (MCP) dans les bâtiments en particulier au niveau de leurs murs fait l'objet depuis plus d'une dizaine d'années d'un intérêt croissant et d'un nombre important de travaux. La présente étude concerne les applications liées à l'isolation thermique et à l'augmentation de l'inertie thermique des parois l...
For the unsteady simulation of compressible subsonic flows (Large Eddy Simulation or Direct Numerical Simulation), the proper handling of the inlet boundary is a challenging task. Indeed, inflow generation through imposition of the velocity may lead to a non-physical reflection of the upstream acoustic waves. In the present contribution, a method t...
In this paper, an updated review of the state of technology and installations of several energy storage technologies were presented, and their various characteristics were analyzed. The analyses included their storage properties, current state in the industry and feasibility for future installation. The paper includes also the main characteristics...
The heat transfer characteristics during melting of the (phase change material) PCM dispersed inside an emulsion are investigated theoretically and experimentally by using (differential scanning calorimeter) DSC. Genetic algorithm is used to determine the unknown parameters in the physical model. The dispersed PCMs are hexadecane, heptadecane and o...
For low Mach number flow calculation, when acoustic waves have to be captured, semi-
implicit methods allow to avoid the time-step limitation that arises when explicit schemes
are used. A method is suggested to solve the boundary equations so that the semi-
implicitness of the algorithm is maintained, as well as its pressure–velocity coupling. This...
test facility featuring jet(s) in cross flow con-figuration is presented. The peculiarity of the rig stems from the presence of an acoustic forcing sys-tem that introduces planar acoustic waves in the cross flow. Microphones, PIV and LDV measure-ments have been conducted in forced and unforced configurations. The experimental database built so far...
The proper scaling of the pressure–velocity coupling that arises from the momentum interpolation approach for unsteady calculation in low Mach number flow is first identified. Then, it is used to suggest a modification of the AUSM+-up scheme that allows acoustic simulations in low Mach number flow.
The present study is devoted to the analysis of the behaviour of the flow through an effusion-cooled aeronautical combustor
model. High-fidelity calculations are performed on an experimental model of a combustion chamber multi-perforated wall and
compared to experimental measurements. The effect of combustion instability on the effusion-cooling sys...
For low Mach number flow calculation, when acoustic waves have to be captured, semi-implicit methods allow to avoid the time-step limitation that arises when explicit schemes are used. A method is suggested to solve the boundary equations so that the semi-implicitness of the algorithm is maintained, as well as its pressure-velocity coupling. This m...
Heat transfer characteristic during crystallization of the phase change material (PCM) dispersed inside an emulsion is investigated theoretically and experimentally by using Differential Scanning Calorimeter (DSC) technique. The dispersed PCMs are hexadecane, octadecane and water. Nucleation laws are used to simulate the supercooling phenomenon. Th...
Low Mach number flow computation in co-located grid arrangement requires pressure–velocity coupling in order to prevent the checkerboard phenomenon. Two broad categories of pressure–velocity coupling methods for unsteady flows can be distinguished based on the time-step dependency of the coupling coefficient in the definition of the transporting ve...
The present numerical study is concerned with the use of phase change materials (PCMs) in solar-based domestic hot water (DHW) systems. During the last decade, the majority of the studies related to that issue concluded that the recourse to PCMs-based storage units was quite promising in order to enhance the overall performances of solar-based DHW...
L'étude thermo-acoustique de chambres de combustion aéronautiques requiert l'implémentation de conditions aux limites pertinentes. Ceci passe en particulier, par la modélisation approprié de l'impédance acoustique associé aux parois multiperforées. La présente étude établit un panorama d'ensemble des approches théoriques et des modèles d'impédance...
The present study aims at providing a complete picture of the various propagation scenarios that a statistically stationary turbulent premixed flame may possibly undergo. By explicitly splitting the scalar turbulent flux between its gradient and counter-gradient contributions, the scalar governing equation is rewritten as an ordinary differential e...
Low Mach number flow computation in co-located grid arrangement requires pressure-velocity coupling in order to prevent the
checkerboard phenomenon. A Rhie-Chow interpolation technique can be formulated with such a coupling involving an explicit
time step dependence, suitable for unsteady computations. Following this approach, it is observed that u...
Numerical dissipation is necessary in low Mach number flow compu-
tations on co-located grids to avoid checkerboard decoupling, which corresponds
to non-physical pressure oscillations. A commonly used technique to cancel out
checkerboard decoupling consists in introducing a relation between the mass flux
and the pressure difference on cell faces, w...
The interaction of a planar supersonic air flow with the hydrogen jet injected perpendicularly across the slot from the duct
walls is studied numerically. An algorithm is constructed for solving the Favre-averaged Navier — Stokes equations for the
flow of a thermally perfect multicomponent gas based on the ENO scheme. The influence of the jet Mach...
The objective of this work is to investigate numerically a storage system formed by a cylindrical tank which is randomly packed with spheres having uniform sizes and encapsulating paraffin as phase change material (PCM). The packed bed is tested for various complex input temperature signals of the working fluid as well as for different internal lay...
The combination of nonreflective boundary conditions with SIMPLE-type algo-rithms is not straightforward, due to the time staggered treatment of the physical variables in these algorithms. First, a model algorithm is described, such as to bring together classi-cal features of SIMPLE-type approaches for compressible flows. As we focus on low Mach nu...
In this paper, the asymptotic behavior of a thermal latent-energy storage system undergoing periodic charge/discharge cycles is numerically investigated. The system consists of a cylindrical tank, which is randomly packed with spheres having uniform sizes and encapsulating paraffin as phase change material. The working fluid flowing through the bed...
This contribution is aimed at drawing the attention of the computational fluid dynamics community on the availability of an
experimental database regarding turbulent lean premixed prevaporised (LPP) reacting flows stabilised behind a double symmetric,
plane sudden expansion fed by two fully developed turbulent channel flows of air plus propane. Thi...
This work aims at developing/combining numerical tools adapted to the simulation of the near field of highly underexpanded jets. An overview of the challenging numerical problems related to the complex shock/expansion structure encountered in these flows is given and an efficient and low-cost numerical strategy is proposed to overcome these, even o...
Abstract In 1995, ONERA initiated a research,program,on,ramjet developments,with,the,support,of the,French,“Délégation,Générale,de l’Armement” (DGA/SPNuM, Ministry of Defense).,The,targeted,final objective,of,this,program,was,to improve,the,ramjet,combustion chamber,design,by,using,both experiments,and,validated,CFD codes. Among,the,various,mechani...
On présente un modèle pour simuler le mélange turbulent et la réaction chimique. L'approche utilise des particules fluides élémentaires (PFE) où la concentration est homogène. Ces particules sont regroupées au sein de macro-particules fluides (MPF). Par une méthode de type Monte-Carlo, l'évolution temporelle des concentrations est simulée par diffé...
Le mélange joue un rôle important dans le développement et le maintien d'une flamme. Ce rôle est encore plus important dans le cas où la combustion se développe au sein de petits volumes (< 1 cm3) et se caractérise alors par les faibles valeurs du nombre de Reynolds associé. Cette configuration se retrouve en particulier au sein des micro-turbines...
A preconditioning approach based on the artificial compressibility formulation is extended to solve the governing equations for unsteady turbulent reactive flows with heat release, at low Mach numbers, on an unstructured hybrid grid context. Premixed reactants are considered and a flamelet approach for combustion modelling is adopted using a contin...
A pseudo-compressibility method for zero Mach number turbulent reactive flows with heat release is combined with an unstructured finite volume hybrid grid scheme. The spatial discretization is based on an overlapped cell vertex approach. An infinite freely planar flame propagating into a turbulent medium of premixed reactants is considered as a tes...
A preconditioning approach based on the artificial compressibility formulation is extended to solve the governing equations for unsteady turbulent reactive flows with heat release, at low Mach numbers, on an unstructured hybrid grid context. Premixed reactants are considered and a flamelet approach for combustion modeling is adopted using a continu...
The present work is devoted to an experimental determination of the influence of an inlet equivalence ratio difference on the contribution of the coherent and stochastic motions to the flow motion in a turbulent premixed propane-air flame stabilised behind a double symmetrical, plane sudden expansion. The flow under investigation is fed by two full...
In this study, it is shown that derivation of the propagation properties of the mean reaction zone by analyzing the characteristic equations in the vicinity of the reactant side only is, in general, not sufficient. When countergradient diffusion (CGD) is present, the products side may also impose some constraint on the propagation velocity spectrum...
An experimental study of inert and combusting flows developing over a plane-symmetric expansion is presented. The Row under investigation consists of two fully developed turbulent channel Rows of air (inert flows) or air plus propane (combusting flows) that are emerging just ahead of the sudden expansion. Such a flow geometry has been chosen to tes...
A numerical study of a turbulent premixed flame stabilized by a stagnation flow is presented. Such a geometry has been chosen because it features most of the phenomena that are encountered in systems of practical interest such as the interaction between the flame and a solid wall and the presence of important streamlines curvature. This study is ba...
The artificial compressibility method is extended to the case of unsteady turbulent reacting flows at low Mach number. The resulting scheme is applied to the calculation of a propagating one-dimensional (1D) planar turbulent flame with a realistic heat release parameter. An eddy break-up-like approach, with a conventional gradient expression for th...
