Academic literature on the topic 'LBM (Méthode de Lattice Boltzmann)'
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Journal articles on the topic "LBM (Méthode de Lattice Boltzmann)":
1
Zhou, Jian Guo. "Macroscopic Lattice Boltzmann Method." Water 13, no. 1 (December 30, 2020): 61. http://dx.doi.org/10.3390/w13010061.
Abstract:
The lattice Boltzmann method (LBM) is a highly simplified model for fluid flows using a few limited fictitious particles. It has been developed into a very efficient and flexible alternative numerical method in computational physics, demonstrating its great power and potential for resolving more and more challenging physical problems in science and engineering covering a wide range of disciplines such as physics, chemistry, biology, material science and image analysis. The LBM is implemented through the two routine steps of streaming and collision using the three parameters of the lattice size, particle speed and collision operator. A fundamental question is if the two steps are integral to the method or if the three parameters can be reduced to one for a minimal lattice Boltzmann method. In this paper, it is shown that the collision step can be removed and the standard LBM can be reformulated into a simple macroscopic lattice Boltzmann method (MacLAB). This model relies on macroscopic physical variables only and is completely defined by one basic parameter of the lattice size δx, bringing the LBM into a precise “lattice” Boltzmann method. The viscous effect on flows is naturally embedded through the particle speed, making it an ideal automatic simulator for fluid flows. Three additional advantages compared to the existing LBMs are that: (i) physical variables can directly be retained as the boundary conditions; (ii) much less computational memory is required; and (iii) the model is unconditionally stable. The findings are demonstrated and confirmed with numerical tests including flows that are independent of and dependent on fluid viscosity, 2D and 3D cavity flows and an unsteady Taylor–Green vortex flow. This provides an efficient and powerful model for resolving physical problems in various disciplines of science and engineering.
2
Maier, Robert S., and Robert S. Bernard. "Accuracy of the Lattice-Boltzmann Method." International Journal of Modern Physics C 08, no. 04 (August 1997): 747–52. http://dx.doi.org/10.1142/s0129183197000631.
Abstract:
The accuracy of the lattice-Boltzmann method (LBM) is moderated by several factors, including Mach number, spatial resolution, boundary conditions, and the lattice mean free path. Results obtained with 3D lattices suggest that the accuracy of certain two-dimensional (2D) flows, such as Poiseuille and Couette flow, persist even when the mean free path between collisions is large, but that of the 3D duct flow deteriorates markedly when the mean free path exceeds the lattice spacing. Accuracy in general decreases with Knudsen number and Mach number, and the product of these two quantities is a useful index for the applicability of LBM to 3D low-Reynolds-number flow. The influence of boundary representations on LBM accuracy is captured by the proposed index, when the accuracy of the prescribed boundary conditions is consistent with that of LBM.
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Parise, G., A. Cianchi, A. Del Dotto, F. Guglietta, A. R. Rossi, and M. Sbragaglia. "Lattice Boltzmann simulations of plasma wakefield acceleration." Physics of Plasmas 29, no. 4 (April 2022): 043903. http://dx.doi.org/10.1063/5.0085192.
Abstract:
We explore a novel simulation route for Plasma Wakefield Acceleration (PWFA) by using the computational method known as the Lattice Boltzmann Method (LBM). LBM is based on a discretization of the continuum kinetic theory while assuring the convergence toward hydrodynamics for coarse-grained fields (i.e., density, velocity, etc.). LBM is an established numerical analysis tool in computational fluid dynamics, able to efficiently bridge between kinetic theory and hydrodynamics, but its application in the context of PWFA has never been investigated so far. This paper takes a step forward to fill this gap. Results of LBM simulations for PWFA are discussed and compared with those of a code (Architect) implementing a Cold Fluid (CF) model for the plasma. In the hydrodynamic framework, we discuss the importance of regularization effects related to diffusion properties intrinsic of the LBM, allowing to go beyond the CF approximations. Issues on computational efficiency are also addressed.
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Parise, G., A. Cianchi, A. Del Dotto, F. Guglietta, A. R. Rossi, and M. Sbragaglia. "Lattice Boltzmann simulations of plasma wakefield acceleration." Physics of Plasmas 29, no. 4 (April 2022): 043903. http://dx.doi.org/10.1063/5.0085192.
Abstract:
We explore a novel simulation route for Plasma Wakefield Acceleration (PWFA) by using the computational method known as the Lattice Boltzmann Method (LBM). LBM is based on a discretization of the continuum kinetic theory while assuring the convergence toward hydrodynamics for coarse-grained fields (i.e., density, velocity, etc.). LBM is an established numerical analysis tool in computational fluid dynamics, able to efficiently bridge between kinetic theory and hydrodynamics, but its application in the context of PWFA has never been investigated so far. This paper takes a step forward to fill this gap. Results of LBM simulations for PWFA are discussed and compared with those of a code (Architect) implementing a Cold Fluid (CF) model for the plasma. In the hydrodynamic framework, we discuss the importance of regularization effects related to diffusion properties intrinsic of the LBM, allowing to go beyond the CF approximations. Issues on computational efficiency are also addressed.
5
Li, Yanbing, and Xiaowen Shan. "Lattice Boltzmann method for adiabatic acoustics." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 369, no. 1944 (June 13, 2011): 2371–80. http://dx.doi.org/10.1098/rsta.2011.0109.
Abstract:
The lattice Boltzmann method (LBM) has been proved to be a useful tool in many areas of computational fluid dynamics, including computational aero-acoustics (CAA). However, for historical reasons, its applications in CAA have been largely restricted to simulations of isothermal (Newtonian) sound waves. As the recent kinetic theory-based reformulation establishes a theoretical framework in which LBM can be extended to recover the full Navier–Stokes–Fourier (NS) equations and beyond, in this paper, we show that, at least at the low-frequency limit (sound frequency much less than molecular collision frequency), adiabatic sound waves can be accurately simulated by the LBM provided that the lattice and the distribution function ensure adequate recovery of the full NS equations.
6
Mendl, Christian B. "Matrix-valued quantum lattice Boltzmann method." International Journal of Modern Physics C 26, no. 10 (June 24, 2015): 1550113. http://dx.doi.org/10.1142/s0129183115501132.
Abstract:
We devise a lattice Boltzmann method (LBM) for a matrix-valued quantum Boltzmann equation, with the classical Maxwell distribution replaced by Fermi–Dirac functions. To accommodate the spin density matrix, the distribution functions become 2 × 2 matrix-valued. From an analytic perspective, the efficient, commonly used BGK approximation of the collision operator is valid in the present setting. The numerical scheme could leverage the principles of LBM for simulating complex spin systems, with applications to spintronics.
7
Wen, Mengke, Weidong Li, and Zhangyan Zhao. "A hybrid scheme coupling lattice Boltzmann method and finite-volume lattice Boltzmann method for steady incompressible flows." Physics of Fluids 34, no. 3 (March 2022): 037114. http://dx.doi.org/10.1063/5.0085370.
Abstract:
We present a new hybrid method coupling the adaptive mesh refinement lattice Boltzmann method (AMRLBM) and the finite-volume lattice Boltzmann method (FVLBM) to improve both the simulation efficiency and adaptivity for steady incompressible flows with complex geometries. The present method makes use of the domain decomposition, in which the FVLBM sub-domain is applied to the region adjacent to the walls, and is coupled to the lattice Boltzmann method (LBM) sub-domain in the rest of the flow field to enhance the ability of the LBM to deal with irregular geometries without sacrificing the high efficiency and accuracy property of the LBM. In the LBM sub-domain, a cell-centered lattice structure-based AMRLBM is used and, in the FVLBM sub-domain, the gas-kinetic Bhatnagar–Gross–Krook (BGK) scheme-based FVLBM is adopted to reduce the numerical dissipation and enhance the efficiency of FVLBM. Moreover, not like the conventional LBM and Navier–Stokes equation solver-based hybrid schemes, the present hybrid scheme combines two kinds of lattice Boltzmann equation solvers, that is, AMRLBM and FVLBM, which makes the present scheme much simpler and better consistency than the conventional hybrid schemes. To assess the accuracy and efficacy of the proposed method, various benchmark studies, including the Kovasznay flow, the lid-driven cavity flow with Reynolds number [Formula: see text], 400, and 1000, and the steady flow past a cylinder with [Formula: see text] and 40, are also conducted. The numerical results show that the present scheme can be an efficient and reliable method for steady incompressible flows.
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Tubbs, Kevin R., and Frank T. C. Tsai. "MRT-Lattice Boltzmann Model for Multilayer Shallow Water Flow." Water 11, no. 8 (August 6, 2019): 1623. http://dx.doi.org/10.3390/w11081623.
Abstract:
The objectives of this study are to introduce a multiple-relaxation-time (MRT) lattice Boltzmann model (LBM) to simulate multilayer shallow water flows and to introduce graphics processing unit (GPU) computing to accelerate the lattice Boltzmann model. Using multiple relaxation times in the lattice Boltzmann model has an advantage of handling very low kinematic viscosity without causing a stability problem in the shallow water equations. This study develops a multilayer MRT-LBM to solve the multilayer Saint-Venant equations to obtain horizontal flow velocities in various depths. In the multilayer MRT-LBM, vertical kinematic viscosity forcing is the key term to couple adjacent layers. We implemented the multilayer MRT-LBM to a GPU-based high-performance computing (HPC) architecture. The multilayer MRT-LBM was verified by analytical solutions for cases of wind-driven, density-driven, and combined circulations with non-uniform bathymetry. The results show good speedup and scalability for large problems. Numerical solutions compared well to the analytical solutions. The multilayer MRT-LBM is promising for simulating lateral and vertical distributions of the horizontal velocities in shallow water flow.
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Falcucci, Giacomo, Stefano Ubertini, Gino Bella, and Sauro Succi. "Lattice Boltzmann Simulation of Cavitating Flows." Communications in Computational Physics 13, no. 3 (March 2013): 685–95. http://dx.doi.org/10.4208/cicp.291011.270112s.
Abstract:
AbstractThe onset of cavitating conditions inside the nozzle of liquid injectors is known to play a major role on spray characteristics, especially on jet penetration and break-up. In this work, we present a Direct Numerical Simulation (DNS) based on the Lattice Boltzmann Method (LBM) to study the fluid dynamic field inside the nozzle of a cavitating injector. The formation of the cavitating region is determined via a multi-phase approach based on the Shan-Chen equation of state. The results obtained by the LBM simulation show satisfactory agreement with both numerical and experimental data. In addition, numerical evidence of bubble break-up, following upon flow-induced cavitation, is also reported.
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SHET, ANIRUDDHA G., K. SIDDHARTH, SHAHAJHAN H. SORATHIYA, ANAND M. DESHPANDE, SUNIL D. SHERLEKAR, BHARAT KAUL, and SANTOSH ANSUMALI. "ON VECTORIZATION FOR LATTICE BASED SIMULATIONS." International Journal of Modern Physics C 24, no. 12 (November 13, 2013): 1340011. http://dx.doi.org/10.1142/s0129183113400111.
Abstract:
We present a vector-friendly blocked computing strategy for the lattice Boltzmann method (LBM). This strategy, along with a recently developed data structure, Structure of Arrays of Structures (SoAoS), is implemented for multi-relaxation type lattice Boltzmann (LB). The proposed methodology enables optimal memory bandwidth utilization in the advection step and high compute efficiency in the collision step of LB implementation. In a dense computing environment, current performance optimization framework for LBM is able to achieve high single-core efficiency.
Dissertations / Theses on the topic "LBM (Méthode de Lattice Boltzmann)":
1
Wissocq, Gauthier. "Investigation of lattice Boltzmann methods for turbomachinery secondary air system simulations." Thesis, Aix-Marseille, 2019. http://www.theses.fr/2019AIXM0635.
Abstract:
Ce manuscrit présente une étude du potentiel des méthodes lattice Boltzmann pour traiter des écoulements circulant dans les systèmes de refroidissement des turbomachines. La combinaison de phénomènes physiques complexes donne naissance à des structures instationnaires, non-axisymmétriques et de période a priori inconnue. Leur bonne modélisation représente un défi pour la simulation numérique en mécanique des fluides. Ce travail peut être divisé en trois sous-parties. Une étude physique des instabilités à l'origine des structures tourbillonnaires est d'abord effectuée par analyse de stabilité linéaire des écoulements. Ensuite, les méthodes lattice Boltzmann sont introduites et leurs problèmes de stabilités numériques sont étudiés via des analyses basées sur l'approche de von Neumann. Enfin, la méthode est évaluée sur des simulations académiques de complexité croissante représentatives des systèmes d'air secondaire, nécessitant des simulations à flux de chaleur conjuguésThis thesis provides an investigation on the use of lattice Boltzmann methods to treat turbomachinery secondary cooling systel flows. The combination of complex physical phenomena (rotating environment with high temperature fluctuations) gives rise to unsteady, non-axisymmetric structures with a priori unknown periodicity. Their modelling, required for a correct heat transfer prediction, represents a challenge for numerical simulations in fluid mechanics. This work can be divided into three sub-sections. A physical study of the instabilities at the origin of unsteady structures is first carried out by analyzing the linear stability of the flows. Lattice Boltzmann methods are then introduced and their numerical stability issues are studied through analyses based on the von Neumann approach. Finally, the method is assessed on academic simulations of increasing complexity representative of secondary air systems, requiring conjugate heat transfer simulations
2
Cheylan, Isabelle. "Optimisation de forme avec la méthode adjointe appliquée aux équations de Lattice-Boltzmann en aérodynamique." Thesis, Aix-Marseille, 2019. http://www.theses.fr/2019AIXM0119.
Abstract:
Cette thèse a pour objectif le développement d’un solveur adjoint dans ProLB, le logiciel d’aérodynamique basé sur la méthode de Lattice-Boltzmann utilisé chez Renault. Ce solveur adjoint permet de calculer les sensibilités surfaciques des efforts aérodynamiques sur un obstacle, typiquement un véhicule, par rapport à la forme de celui-ci. L’objectif final est de le déformer, par des techniques de morphing basées sur une méthode de descente du gradient à pas constant, afin de réduire sa traînée aérodynamique. Dans un premier temps, l’étude de cas 2D laminaires permet de détailler le développement du solveur adjoint étape par étape. Le choix de la formulation de la force de traînée est un point important. Une étude a montré qu’il est plus judicieux de calculer cette force dans le sillage de l’objet plutôt que sur l’objet lui-même. L’objectif étant de minimiser la force de traînée moyenne, il a été montré que le meilleur compromis entre l’effort de calcul et la précision des gradients est obtenu en moyennant en temps le champ direct instationnaire. Dans un second temps, l’étude de cas 3D turbulents à grandes échelles a permis de montrer que les algorithmes fonctionnant sur des cas 2D laminaires ne sont pas suffisamment stables pour être utilisés dans ce contexte beaucoup plus complexe. Des modifications ont donc été apportées au solveur adjoint afin de pouvoir l’utiliser dans un contexte industriel. Il permet d’obtenir une cartographie des sensibilités sur tout le véhicule dans un écoulement à Reynolds élevé. Une boucle d’optimisation complète a été réalisée, avec une étape de lissage des sensibilités, et a permis de réduire la force de traînée de 5%This work aims at developing an adjoint solver in ProLB, the aerodynamic software based on the Lattice-Boltzmann method used by Renault. The adjoint solver makes it possible to calculate the surface sensitivities of the aerodynamic forces acting on an obstacle, such as a vehicle, with respect to its shape. The final purpose is to deform it, using morphing techniques based on a fixed step gradient descent method, in order to reduce its drag. First, the step by step development process of the adjoint solver is shown through 2D laminar test cases. The choice of the drag force expression is important because it has an impact on the complexity of the adjoint equations and on the gradient calculation. It is shown that calculating the drag force in the wake of the obstacle is more adequate than calculating it on the obstacle directly. The aim being to minimize the time-averaged drag force, it is demonstrated that the best trade-off between the gradients accuracy and the computation cost is obtained by time-averaging the unsteady direct field. Then, the study of 3D large-scale turbulent cases shows that the algorithms used for the 2D laminar cases are not stable enough to be used in this more complicated context. Changes have therefore been brought to the adjoint solver, in order to use it in an industrial context. Every assumption used for the development of the adjoint solver is justified and referenced. The adjoint solver is finally applied to an industrial test case. It gives a sensitivity map on a vehicle in a high Reynolds number flow. A complete optimization loop is performed, using a smoothing step on the sensitivities, and gives a 5% reduction of the drag force
3
Walther, Édouard. "Contribution de la Lattice Boltzmann Method à l’étude de l’enveloppe du bâtiment." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLN004/document.
Abstract:
Les enjeux de réduction des consommations d’énergie, d’estimation de la durabilité ainsi que l’évolution des pratiques constructives et réglementaires génèrent une augmentation significative du niveau de détail exigé dans la simulation des phénomènes physiques du Génie Civil pour une prédiction fiable du comportement des ouvrages. Le bâtiment est le siège de phénomènes couplés multi-échelles, entre le microscopique (voire le nanoscopique) et le macroscopique, impliquant des études de couplages complexes entre matériaux, à l’instar des phénomènes de sorption-désorption qui influent sur la résistance mécanique, les transferts de masse, la conductivité, le stockage d’énergie ou la durabilité d’un ouvrage. Les méthodes numériques appliquées permettent de résoudre certains de ces problèmes en ayant recours aux techniques de calcul multi-grilles, de couplage multi-échelles ou de parallélisation massive afin de réduire substantiellement les temps de calcul. Dans le présent travail, qui traite de plusieurs simulations ayant trait à la physique du bâtiment, nous nous intéressons à la pertinence d’utilisation de la méthode "Lattice Boltzmann". Il s’agit d’une méthode numérique construite sur une grille – d’où l’appellation de lattice – dite "mésoscopique" qui, à partir d’un raisonnement de thermodynamique statistique sur le comportement d’un groupes de particules microscopiques de fluide, permet d’obtenir une extrapolation consistante vers son comportement macroscopique. Après une étude les avantages comparés de la méthode et sur le comportement oscillatoire qu'elle exhibe dans certaines configurations, on présente :- une application au calcul des propriétés diffusives homogénéisée des matériaux cimentaires en cours d'hydratation, par résolution sur le cluster du LMT.- une application à l'énergétique du bâtiment avec la comportement d'une paroi solaire dynamique, dont le calcul a été porté sur carte graphique afin d'en évaluer le potentielReducing building energy consumption and estimating the durability of structures are ongoing challenges in the current regulatory framework and construction practice. They suppose a significant increase of the level of detail for simulating the physical phenomena of Civil Engineering to achieve a reliable prediction of structures.Building is the centre of multi-scale, coupled phenomena ranging from the micro (or even nano) to the macro-scale, thus implying complex couplings between materials such as sorption-desorption process which influences the intrinsic properties of matter such as mechanical resistance, mass transfer, thermal conductivity, energy storage or durability.Applied numerical methods allow for the resolution of some of these problems by using multi-grid computing, multi-scale coupling or massive parallelisation in order to substantially reduce the computing time.The present work is intended to evaluate the suitability of the “lattice Boltzmann method” applied to several applications in building physics. This numerical method, said to be “mesoscopic”, starts from the thermodynamic statistical behaviour of a group of fluid particles, mimicking the macroscopic behaviour thanks to a consistent extrapolation across the scales.After having studied the comparative advantages of the method and the oscillatory behaviour it displays under some circumstances, we present - An application to the diffusive properties of cementitious materials during hydration via numerical homogenization and cluster-computing numerical campaign - An application to building energy with the modeling of a solar active wall in forced convection simulated on a graphical processing unit
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Rehhali, Khaoula. "Simulations de la convection naturelle couplée au rayonnement surfacique par la méthode de Boltzmann sur réseau : cas des chauffages variable et discret." Electronic Thesis or Diss., Amiens, 2019. http://www.theses.fr/2019AMIE0001.
Abstract:
Cette thèse s'inscrit dans le cadre d'une étude numérique visant à étudier les phénomènes de couplage de la convection naturelle et du rayonnement surfacique dans des cavités carrées dont les parois sont soumises à des chauffages discrets ou non-uniformes. En effet, la première étude réalisée s'intéresse à un problème de couplage convection-rayonnement dans une cavité carrée inclinée et remplie d'air, ayant d'un côté une paroi chauffée à une température constante et du côté opposé, une paroi chauffée linéairement. Les parois restantes sont considérées adiabatiques. Dans la seconde étude, la cavité a des parois verticales partiellement chauffées (symétriquement et asymétriquement), une paroi supérieure refroidie et une paroi inférieure adiabatique. L'objectif de ces études numériques réside dans l'analyse de l'effet du rayonnement surfacique et des différents paramètres gouvernants (mode de chauffage, nombre de Rayleigh, angle d'inclinaison, différence de température) sur la structure d'écoulement et le transfert de chaleur. Le second objectif de cette thèse consiste à tester la performance du schéma à temps de relaxation multiple (MRT) de la méthode Lattice Boltzmann (LBM) en présence du couplage convection-rayonnement. Les résultats de ce travail ont révélé que les paramètres de contrôle considérés ont un effet important sur la structure de l'écoulement et le transfert de chaleur à travers la cavitéIn this thesis, a numerical study is carried out on the coupling phenomena between natural convection and surface radiation in square cavities whose walls are subjected to discrete or non-uniform temperatures. Indeed, the first study carried out is concerned with a problem of convection-radiation coupling in a square cavity inclined and filled with air, having on one side a wall heated at a constant temperature and on the opposite side, a wall heated linearly. The remaining walls are considered adiabatic. In the second study, the cavity has partially heated vertical walls (symmetrically and asymmetrically), a cooled upper wall and an adiabatic bottom wall. The objective of these numerical studies is to analyze the effect of surface radiation and the different governing parameters (heating mode, Rayleigh number, angle of inclination, temperature difference) on the flow structure and the heat transfer. The second objective of this thesis is to test the performance of the multiple relaxation time (MRT) scheme of the Lattice-Boltzmann method (LBM) in the presence of convection radiation coupling. The results of this study revealed that the considered governing parameters have a significant effect on the flow structure and heat transfer through the cavity
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Cao, Weijin. "Investigation of the applicability of the lattice Boltzmann method to free-surface hydrodynamic problems in marine engineering." Thesis, Ecole centrale de Nantes, 2019. http://www.theses.fr/2019ECDN0011/document.
Abstract:
La simulation numérique des écoulements à surface libre pour les applications du génie maritime est un problème qui présente de grands défis dans le domaine de la dynamique des fluides numérique (CFD). On propose dans cette thèse une solution, qui consiste à utiliser la méthode de Boltzmann sur réseau régularisée (RLBM) avec un modèle de surface libre basé sur le volume-de-fluide (VOF), et on étudie sa faisabilité et sa fiabilité. Les connaissances théoriques de la méthode de Boltzmann sur réseau (LBM) sont présentées dans un premier temps, sur la base d'un développement polynomial d'Hermite et d'une analyse de Chapman-Enskog. De cette perspective, l’idée de la RLBM se résume comme étant la régularisation d'Hermite des fonctions de distribution. Dans les cas tests suivants du vortex de Taylor-Green et de la cavité entraînée, il est vérifié que la RLBM posse possède une précision de second ordre et une stabilité améliorée. On a alors ensuite implémenté le modèle de surface libre dans la RLBM. Sur la simulation d'une onde de gravité visqueuse stationnaire et d'un écoulement de dambreak, il est montré que la régularisation stabilise fortement le calcul en réduisant les oscillations de pression, ce qui est très bénéfique pour obtenir des écoulements à surface libre précis, et que la RLBM n'introduit pas non plus de dissipation numérique supplémentaire. De plus, une nouvelle méthode de reconstruction des fonctions de distribution à la surface libre est proposée. Le modèle proposé est ainsi plus consistent avec la RLBM, ce qui offre un moyen efficace pour simuler des écoulements à surface libre à un grand nombre de Reynolds en génie maritimeThe numerical simulation of the freesurface flows for marine engineering applications is a very challenging issue in the field of computational fluid dynamics (CFD). In this thesis, we propose a solution, which is to use the regularized lattice Boltzmann method (RLBM) with a volume-of-fluid (VOF) based single-phase free-surface lattice Boltzmann (LB) model, and we investigate its feasibility and its reliability. The theoretical insights of the lattice Boltzmann method (LBM) are given at first, through the Hermite expansion and the Chapman-Enskog analysis. From this perspective, the idea of the RLBM is summarized as the Hermite regularization of the distribution functions. On the test-cases of the Taylor-Green vortex and the lid-driven cavity flow, the RLBM is verified to have a 2nd-order accuracy and an improved stability. The adopted free-surface model is then implemented into the RLBM and validated through simulating a viscous standing wave and a dambreak flow problems. It is shown that the regularization not only strongly stabilizes the calculation by reducing spurious pressure oscillations, which is very beneficial for obtaining accurate free-surface motions, but also does not introduce any extra numerical dissipation. Furthermore, a new reconstruction method for the distribution functions at the free-surface is proposed. The present model is more consistent with the RLBM, which provides an effective way for simulating high-Reynoldsnumber free-surface flows in marine engineering
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Abassi, Wafik. "Investigations expérimentales et modélisations numériques par la méthode de Lattice Boltzmann (LBM) pour l'étude des transferts dans les écoulements tourbillonnaires." Nantes, 2014. https://archive.bu.univ-nantes.fr/pollux/show/show?id=caaf67b3-c66e-4925-a786-000eb6287dea.
Abstract:
Ce travail numérique et expérimental, porte sur l’étude des instabilités et sur les transferts dans deux configurations d’écoulements tourbillonnaires : Le sillage derrière un obstacle et l’écoulement de Couette-Taylor. Une simulation numérique, basée sur la méthode de « Lattice Boltzmann » (LBM), a été développée pour étudier la dynamique de l’écoulement confiné autour d’un obstacle dans une configuration géométrique 2D et 3D. Une extension de ce code a été effectuée pour simuler le transfert de masse pariétal. Par la suite, des investigations expérimentales sur les mécanismes de transferts dans le sillage d’un obstacle et dans un écoulement de Couette-Taylor ont été réalisées. Les résultats obtenus ont été comparés à ceux de la simulation numérique, validant ainsi notre code développé et mettant en valeur la performance de la méthode LBM. Des résultats expérimentaux qualitatifs (visualisations) et quantitatifs (PIV et polarographie) ont été mis en place pour caractériser les écoulements tourbillonnaires étudiés. Un posttraitement des mesures réalisées par PIV, utilisant des critères de détection et la POD, a été développé. La méthode polarographique, au moyen de sondes simples et une tri-segmentée, a été utilisée pour la détermination du gradient pariétal de vitesse. Une synchronisation entre les mesures obtenues par PIV et celles déterminées par la polarographie, a permis de mieux comprendre les interactions spatiotemporelles entre les tourbillons et les paroisThe numerical and experimental work focuses on the study of instabilities and transfers in two configurations of vortex flows: The wake behind an obstacle and Taylor-Couette flow. A numerical simulation based on the method of "Lattice Boltzmann" (LBM) has been developed to study the dynamics of the confined flow around an obstacle in a 2D and 3D geometry. An extension of this code was performed to enable the wall shear stress simulations (mass transfer). Thereafter, experimental investigations of the mass transfer mechanisms in the wake of an obstacle and in a Taylor-Couette flow were initiated. The results were compared to that obtained by simulation (LBM). The main objective is to check the validity of the developed code and to highlight the LBM performances. Experimental results, qualitative (visualizations) and quantitative (PIV and polarography) were performed to characterize the vortex flows studied. A post-processing of PIV measurements, using vortex detection criteria and POD method were has developed. The polarographic technique, through single probes and one tri-segmented sensor, has contributed to the determination of the wall shear stress. Synchronization between PIV measurements and polarography method, was carried out to understand the spatiotemporal interactions between vortices and the walls
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Stockinger, Claudius. "Study and analysis οf Sοοt Filter Regeneratiοn by using the Lattice Bοltzmann Μethοd." Electronic Thesis or Diss., Normandie, 2024. http://www.theses.fr/2024NORMIR07.
Abstract:
La maîtrise des émissions de noir de carbone est une tâche importante dans de nombreux domaines d'application, le secteur des transports étant l'un des domaines les plus importants. Les moteurs diesel, encore largement utilisés dans le monde entier, sont l'une des principales sources d'émissions anthropiques de noir de carbone. Afin de contrer l'effet néfaste du noir de carbone sur la santé humaine, le traitement des gaz d'échappement est au centre de la recherche depuis de nombreuses décennies. Les filtres à suie de pointe utilisent une structure en nid d'abeille en céramique, agissant comme des filtres à flux mur. Ces filtres nécessitent une régénération périodique une fois qu'une contre-pression de filtre critique est atteinte. La régénération est effectuée soit sous forme de régénération active à des températures élevées (>600 °C), soit en continu, sous forme de régénération passive à des températures à partir de 300 °C. La température nécessaire des gaz d'échappement pour la régénération active entraîne une pénalité en carburant, rendant le contrôle précis du processus de régénération impératif. Des travaux antérieurs ont suggéré que la morphologie mésoscopique de la suie et son évolution pendant la combustion de la suie influencent la réactivité, affectant ainsi le processus de régénération. Par conséquent, le contrôle du système de régénération nécessite une connaissance précise des phénomènes physiques et chimiques en jeu, nécessitant des simulations du processus de régénération. Dans cette thèse, un cadre de simulation pour modéliser l'écoulement de gaz, composé des différentes espèces réactives, en tenant compte des interactions solide-gaz, est créé. De plus, le transfert de chaleur conjugué, les réactions hétérogènes et la libération de chaleur de réaction à l'interface entre les phases solide et gazeuse sont traités. À cette fin, la méthode de Boltzmann sur réseau (LBM), en raison de sa nature mésoscopique, est choisie comme un excellent outil pour modéliser la combustion hétérogène à l'échelle des pores. Dans cette thèse, un cadre LBM est créé et des méthodes appropriées pour modéliser la combustion de la suie sont choisies et largement validées. Une procédure d'utilisation des données de microscopie électronique à balayage par faisceau ionique focalisé (FIB-SEM) de véritables échantillons de suie pour la simulation de combustion est mise en œuvre. De plus, les régimes de combustion sont analysés en fonction de la variation du nombre de Péclet, du nombre de Damköhler et de la fraction molaire d'oxygène dans le flux gazeux d'entrée. Des simulations avec des géométries de suie réalistes sont réalisées et les résultats sont comparés avec des résultats expérimentaux. Il est constaté que l'évolution de la surface réactive spécifique, telle que reçue des simulations LBM, n'est pas comparable aux résultats expérimentaux. L'analyse par microscopie électronique à transmission (TEM) et les spectres Raman de la suie avant et après les expériences de combustion ont révélé que la combustion affecte les particules primaires à l'échelle nanométrique. Pour cette raison, un modèle séparé pour décrire les particules primaires hétérogènes et leur combustion a été créé. Ensuite, les premières simulations avec couplage d'échelle ont été menées, en reliant les simulations LBM mésoscopiques avec la conception des particules primaires à l'échelle nanométrique. Il est démontré qu'une augmentation plus réaliste de la surface spécifique peut être obtenue dans les simulations en couplant le modèle LBM mésoscopique avec un modèle de particules primaires à l'échelle nanométriqueThe control of the emission of carbon black is an important task in many fields of application, with the transport sector being one of the most important domains. Diesel engines, still being extensively used worldwide, are one of the main contributors to the anthropogenic emission of carbon black. In order to counteract the detrimental effect of carbon black on human health, exhaust gas treatment has been the focal point of research for many decades.State of the art soot filters use a ceramic honey-comb structure, acting as wall flow filters. These filters require periodic regeneration once a critical filter back-pressure is reached. Regeneration is conduced either as active regeneration at elevated temperatures (>600 °C) or continuously, as passive regeneration at temperatures starting from 300 °C. The necessary exhaust gas temperature of active regeneration results in a fuel penalty, making the precise control of the regeneration process imperative. Previous works suggested that the mesoscopic morphology of soot and its evolution during soot combustion influence the reactivity, thus affecting the regeneration process. Hence, the control of the regeneration system requires precise knowledge of the physical and chemical phenomena at hand, necessitating simulations of the regeneration process.In this thesis, a simulation framework to model gas flow, consisting of the different reactive species, taking into account solid-gas interactions, is created. Furthermore, conjugate heat transfer, heterogeneous reactions and the release of reaction heat at the interface between the solid and gas phases is treated. For this purpose, the lattice Boltzmann method (LBM), due to its mesoscopic nature, is chosen as an excellent tool to model the heterogeneous combustion on the pore scale. Within this thesis, a LBM framework is created and appropriate methods to model soot combustion are chosen and extensively validated. A procedure to use focused ion beam scanning electron microscopy (FIB-SEM) data of realistic soot samples for the combustion simulation is implemented. Furthermore, the combustion regimes are analysed based on variation of Péclet number, Damköhler number, and oxygen mass fraction in the inlet gas stream. Simulations with realistic soot geometries are performed and the results are compared with experimental results. It is found that the evolution of the specific reactive surface, as received from LBM simulations, is not comparable to the experimental results. Transmission electron microscopy (TEM) analysis and Raman spectra of the soot before and after combustion experiments revealed that combustion affects the primary particles on the nano-scale. For this reason, a separate model to describe the heterogeneous primary particles and their combustion was created. Subsequently, first simulations with scale-coupling were conducted, by connecting the mesoscopic LBM simulations with the primary particle design on the nano-scale. It is shown that a more realistic increase in specific surface could be achieved in simulations by coupling the mesoscopic LBM model with a nano-scale primary particle model
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Tran, Duc Kien. "Modélisation numérique discrète de l'érosion interne par renard hydraulique dans les barrages ou digues en terre." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSEC055/document.
Abstract:
Le travail présenté dans ce mémoire de thèse porte sur la modélisation discrète de l’évolution régressive du front d’un conduit d’érosion qui peut se produire dans les barrages ou digues en remblai. Des outils numériques ont été développés en se basant sur le couplage entre la méthode des éléments discrets (DEM) et la méthode de Boltzmann sur réseau (LBM) pour la description, respectivement, des phases solide et fluide. L’implémentation de la méthode DEM suit une approche standard de type dynamique moléculaire (DM) et les interactions intergranulaires sont modélisées par des contacts unilatéraux visco-élastiques frottants ou bilatéraux (ponts solides) viscoélastiques, afin de permettre la modélisation d’un sol légèrement cohésif. La méthode LBM est implémentée ici avec des temps de relaxation multiples (MRT) et une condition de rebondissement interpolée pour les frontières solides en mouvement, afin d’améliorer la stabilité numérique des calculs. Le schéma du couplage entre les deux méthodes, ainsi que les critères pour le choix des paramètres numériques des deux méthodes. Pour étudier le phénomène visé, un échantillon représentatif de sol granulaire situé au front d’un conduit d’érosion est d’abord assemblé par une procédure de préparation “à sec”, puis testé dans des conditions saturées sous un chargement hydraulique monotone croissant. L’érosion régressive se produit par amas de grains au niveau du front d’érosion ayant subi au préalable une dégradation due à de nombreuses ruptures de ponts solides en traction. L’autre phénomène important observé est la présence d’arcs associés a` des chaines de forces en compression qui parviennent à maintenir parfois totalement, parfois partiellement l’intégrité du matériau non érodéThe work reported in this thesis consists in a discrete modelling of the backward front propagation of an erosion pipe, as can take place in embankment dams or dikes. Some numerical tools have been developed to this end, based on the coupling between the Discrete Element Method (DEM) and the Lattice Boltzmann Method (LBM) for the representation of the solid and uid phases, respectively. The implementation of DEM follows a standard molecular dynamics approach and the interaction among grains are regulated by unilteral frictional visco-elastic and breakable visco-elastic bonds, in order to take into account a slightly cohesive soil behaviour. The LBM was implemented according to the Multiple Relaxation Time (MRT) scheme along with an interpolated non-slip conditions for moving boundaries, in order to improve the numerical stability of the calculations. The coupling scheme is described along with the criteria for the numerical parameters of the two methods. A representative specimen of a granular soil located at the front of an erosion pipe is first assembled by a \dry" preparation precedure and then tested under fully-saturated conditions and increasing hydraulic load over time. Backward erosion is takes place in the form of clusters of grain being eroded at the erosion front after a degradation of the material due to the breakage of tensile bonds. The other interesting feature that was observed is the creation of arches of compressive force chains. These arches enabled the specimen to maintain a stable or metastable configuration under the increasing hydraulic load
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Gendre, Félix. "Développement de méthodes de Boltzmann sur réseau en maillages non-uniformes pour l'aéroacoustique automobile." Thesis, Aix-Marseille, 2018. http://www.theses.fr/2018AIXM0196/document.
Abstract:
L’objectif de ce travail est d’étudier les capacités de la méthode de Boltzmann sur réseau (LBM) dans un cadre numériquement contraignant : celui de la simulation aéroacoustique en maillage non-uniforme, à très haut nombre de Reynolds et à nombre de Mach non négligeable (Ma > 0.1), appliquée à l’automobile. La problématique industrielle est celle du calcul du bruit intérieur d’origine aérodynamique, dont le calcul du champ de pression pariétal instationnaire sur le vitrage conducteur est la première étape décisive. Il a été constaté qu’un manque de précision sur la faible part acoustique du champ de pression total sur le vitrage, provenant très probablement d’erreurs au niveau des transitions de résolution du maillage, était la cause d’une surestimation du bruit intérieur. Nous présentons d’abord une construction cohérente et unifiée de la méthode de Boltzmann sur réseau à partir de l’équation de Boltzmann, dans un cadre athermal faiblement compressible. Nous étudions ensuite en détail les propriétés aéroacoustiques de la LBM, en parcourant toutes les grandes familles d’opérateurs de collision de la littérature. Une variante de modèle à temps de relaxation multiples, utilisable pour l’aéroacoustique, est présentée et testée. Un modèle alternatif simplifié de filtrage sélectif, rapide et compact, est développé et validé. La problématique des maillages non-uniformes est abordée. Un recensement exhaustif des études LBM menées dans ce cadre dans la littérature montre qu’aucune ne correspond à nos contraintes. Des algorithmes alternatifs aux transitions sont développés. Enfin, des applications industrielles sont réalisées à l’aide des modèles développés dans le mémoireThe main goal of this work is to study the capacities of the Lattice Boltzmann Method in a constrained numerical framework : that of numerical simulation in automotive aeroacoustics with non-uniform meshes, at high Reynolds number and non egligible Mach number (Ma > 0.1). The industrial problem is the computation of the interior aerodynamic noise, which includes as its first decisive step the computation of the unsteady wall pressure field on the car windows. It was observed that a lack of precision on the weak acoustic part of the total pressure field on the driver-side window, which is most probably due to errors at mesh refinement interfaces, caused an overestimation of the interior noise. We first present a coherent and unified construction of the Lattice BoltzmannMethod from the Boltzmann equation, in an athermal weakly compressible framework. Then, we study in details the aeroacoustic properties of the LBM by reviewingall the main families of collisional operators that exist in the literature. A variant of multiple relaxation time operator that can be used for aeroacoustics is presented and tested. A simplified alternative selective filter, fast and compact, is developped and numerically validated. The problem of non-uniform meshes is discussed. An exhaustive review of the LBM studies that have been carried out within that framework shows that none of them corresponds to our constraints. Alternative transition nodes algorithms are developed. Finally, all the developed models of this work are applied to industrial cases
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Maquignon, Nicolas. "Vers un modèle multiphases et multicomposants (MPMC) de type Lattice Boltzmann Method (LBM) pour la simulation dynamique d'un fluide cyogénique dans l'eau." Thesis, Littoral, 2015. http://www.theses.fr/2015DUNK0426/document.
Abstract:
Au cours de cette thèse, un modèle LBM MPMC avec échanges thermiques est développé. Des tests d'assimilation de données et des mesures par flot optique sont réalisés en vue d'une validation. Le cadre d'application de cette thèse est celui du mélange d'un fluide cryogénique avec l'eau. Dans une première partie, un travail bibliographique rappelant l'équation de Boltzmann, ses diverses hypothèses et simplifications, ainsi que l'aspect algorithmique de la LBM sont exposés. Une comparaison entre opérateur de collision SRT et MRT est réalisée, et une simulation de phénomènes turbulents à différents nombres de Reynolds est étudiée, notamment avec le benchmark de l'instabilité de Von Karman. Dans une seconde partie, le modèle MPMC de Shan & Cehn est rappelé puis étendu au cas où les échanges thermiques entre composants sont présents. Des validations quantitatives sont faites, notamment avec le benchmark du fluide de Couette à deux phases ou à deux composants, du test de cohérence vis-à-vis de la loi de Laplace, ou encore par rapport à un benchmark faisant intervenir la conduction thermique. Des tests qualitatifs de condensation en milieu multicomposants sont proposés pour valider l'aspect des échanges thermiques entre composants en présence d'une transition de phase. Dans la troisième partie de cette thèse, une méthode de validation par assimilation de données est introduite, avec le filtrage de Kalman d'ensemble. Un test d'estimation d'état d'un fluide di-phasique est réalisé, et la compatibilité du filtrage de Kalman d'ensemble par rapport au modèle LBMMPMC est évaluée. Pour la validation du comportement du modèle d'un point de vue de la présence de deux composants, un fluide de substitution (non-cryogénique) au GNL, le butane, a été choisi pour permettre des observations dans des conditions expérimentales accessibles. Puis, une plateforme expérimentale d'injection de butane liquide dans une colonne d'eau sous pression est présentée. Des images d'ombroscopie issues d'expériences de remontée de butane liquide dans de l'eau sont exposées et un algorithme de calcul de flot optique est appliqué à ces images. Une évaluation qualitative des champs de vitesses obtenus par application de cet algorithme est réaliséeIn this thesis, a LBM MPMC model with heat exchange is developed. Data assimilation tests and optical flow measurements are made in order to validate the model. The application context of this thesis is the mixture of a cryogenic fluid with water. In the first part, a bibliographical work reminding the Boltzmann equation and its various assumptions and simplifications, as well as the algorithmic aspect of the LBM are exposed. A comparison between SRT and MRT collision operator is performed, and a simulation of turbulent phenomena at different Reynolds numbers is studied, especially with the benchmark of the instability from Von Karman. In the second part, the MPMC model from Shan & Chen is reminded and extended to the case of the inter-component heat exchanges. Quantitative validations are made, especially with the benchmark of a two-phase or two-component Couette fluid. Consistency is tested against Laplace's law rule, or against a benchmark involving heat conduction. Qualitative testing of condensations in a multi-component medium are proposed to validate the heat exchange between components in the presence of a phase transition. In the third part of this thesis, a validation method for data assimilation is introduced, with the ensemble Kalman filter. A state estimation test of a bi-phase fluid is realized, and compatibility of the ensemble Kalman filtering to the LBM MPMC model is assessed. For validation of the behavior of the model for a two-component case, a substitution fluid (non-cryogenic) for LNG, butane, was selected to permit observations in experimental conditions which are accessible. Then, an experimental platform of injection of liquid butane in a pressurised water column is presented. Shadowgraph images from liquid butane experiments in water are exposed and an optical flow calculation algorithm is applied to these images. A qualitative assessment of the velocity field obtaines by application of this algorithm is performed
Book chapters on the topic "LBM (Méthode de Lattice Boltzmann)":
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Zhang, Junfeng, and Daniel Y. Kwok. "Lattice Boltzmann Method (LBM)." In Encyclopedia of Microfluidics and Nanofluidics, 1598–604. New York, NY: Springer New York, 2015. http://dx.doi.org/10.1007/978-1-4614-5491-5_800.
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Zhang, Junfeng, and Daniel Y. Kwok. "Lattice Boltzmann Method (LBM)." In Encyclopedia of Microfluidics and Nanofluidics, 1–8. Boston, MA: Springer US, 2013. http://dx.doi.org/10.1007/978-3-642-27758-0_800-4.
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Zhang, Fengshou, Branko Damjanac, and Jason Furtney. "DEM Coupled with Lattice-Boltzmann Method (LBM)." In Coupled Thermo-Hydro-Mechanical Processes in Fractured Rock Masses, 133–59. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-25787-2_5.
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Farhat, Hassan, Joon Sang Lee, and Sasidhar Kondaraju. "Hybrid LBM for Surfactant-Covered Droplets." In Accelerated Lattice Boltzmann Model for Colloidal Suspensions, 69–97. Boston, MA: Springer US, 2014. http://dx.doi.org/10.1007/978-1-4899-7402-0_4.
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Farhat, Hassan, Joon Sang Lee, and Sasidhar Kondaraju. "Nonuniform Interfacial Tension LBM for RBC Modeling." In Accelerated Lattice Boltzmann Model for Colloidal Suspensions, 123–36. Boston, MA: Springer US, 2014. http://dx.doi.org/10.1007/978-1-4899-7402-0_6.
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Farhat, Hassan, Joon Sang Lee, and Sasidhar Kondaraju. "Suppressing the Coalescence in the LBM: Colloids Rheology." In Accelerated Lattice Boltzmann Model for Colloidal Suspensions, 99–121. Boston, MA: Springer US, 2014. http://dx.doi.org/10.1007/978-1-4899-7402-0_5.
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Han, Mengtao, and Ryozo Ooka. "Turbulence Models and LBM-Based Large-Eddy Simulation (LBM-LES)." In Large-Eddy Simulation Based on the Lattice Boltzmann Method for Built Environment Problems, 101–13. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-99-1264-3_5.
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Han, Mengtao, and Ryozo Ooka. "From LBE to LBM: Using the LBM to Solve Built Environment Problems." In Large-Eddy Simulation Based on the Lattice Boltzmann Method for Built Environment Problems, 115–27. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-99-1264-3_6.
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Han, Mengtao, and Ryozo Ooka. "LBM-LES in an Isothermal Indoor Flow Problem." In Large-Eddy Simulation Based on the Lattice Boltzmann Method for Built Environment Problems, 145–71. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-99-1264-3_8.
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Han, Mengtao, and Ryozo Ooka. "LBM-LES in Ideal 3D Lid-Driven Cavity Flow Problems." In Large-Eddy Simulation Based on the Lattice Boltzmann Method for Built Environment Problems, 131–43. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-99-1264-3_7.
Conference papers on the topic "LBM (Méthode de Lattice Boltzmann)":
1
Premnath, Kannan N., Jean-Christophe Nave, and Sanjoy Banerjee. "Computation of Multiphase Flows With Lattice Boltzmann Methods." In ASME 2005 International Mechanical Engineering Congress and Exposition. ASMEDC, 2005. http://dx.doi.org/10.1115/imece2005-80459.
Abstract:
Lattice Boltzmann methods (LBM) have several features that make them attractive for computation of large fluid mechanics problems in complex geometries. For example, in comparison with the conventional projection methods that are widely used in computational fluid dynamics, LBM does not require solution of a pressure Poisson equation which usually accounts for ~ 80% of the computational time required per time step, and it is also local, making parallelization straightforward, and run time on distributed memory architectures linearly scalable. LBM has therefore been considered for direct simulation of multiphase flows, but its application has been limited because of instabililties that arise when the viscosities become small and/or the density mismatch between the fluids is large. Current approaches to computation of multiphase systems using LBM are reviewed, and new approaches based on multiple relaxation times and a regularization procedure which maintain stability at low viscosities are discussed and a technique using time-splitting, that alleviates the density ratio constraint, is proposed. Applications of the LBM to magnetohydrodynamic (MHD) multiphase flows will be discussed.
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Falcucci, Giacomo, Elio Jannelli, Stefano Ubertini, Gino Bella, Alessandro De Maio, and Silvia Palpacelli. "Lattice Boltzmann Simulation of Diesel Injection." In ASME 2012 Heat Transfer Summer Conference collocated with the ASME 2012 Fluids Engineering Division Summer Meeting and the ASME 2012 10th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/ht2012-58175.
Abstract:
The evaluation and improvement of internal combustion engine performance is a challenge of major importance and it has been the object of research efforts over the last centuries. Phenomena like fuel cavitation inside diesel injector nozzles, the formation of spray and its break-up in the combustion chamber as well as the impingement of fuel droplets on engine walls are known to have a great influence on energy release during combustion and on pollutant formation and emissions, as well. In this work, a methodology based on the Lattice Boltzmann Method (LBM) is used to directly simulate phenomena affecting diesel injection. LBM is a numerical method based on Boltzmann’s Kinetic Equation, which has been successfully employed in recent years for the simulation of phenomena of technical interest. The results of LB simulations are displayed and compared to experimental data from literature, proving the accuracy of the proposed investigation method.
3
Sajjadi, H., M. Salmanzadeh, and G. Ahmadi. "Indoor Airflow Simulation Using Lattice Boltzmann Method." In ASME 2014 4th Joint US-European Fluids Engineering Division Summer Meeting collocated with the ASME 2014 12th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/fedsm2014-21618.
Abstract:
Indoor air quality (IAQ) is very important to human health and comfort as increasingly people spent most of their time in indoor environment. Numerical simulation of indoor airflows has become a significant tool for investigation of the indoor air quality. Cost effective computational methods with reasonable accuracy have the advantage of being more accessible to designers compared to more precise but expensive DNS methods. Recently developed Lattice-Boltzmann Method (LBM) has proved to be a powerful numerical technique for simulating fluid flows in various applications. In comparison with the conventional CFD methods, the advantages of LBM are: simple calculation procedure, simple and efficient implementation for parallel computation, and easy and robust handling of complex geometries. The indoor airflow is typically in turbulent flow regimes. Due to the high costs of more accurate direct numerical simulation (DNS) and large eddy simulation (LES), in this study the Reynolds Averaged Navier-Stokes (RANS) method was used for analyzing the turbulent flow conditions. The RANS governing equations, and in particular, the k-ε turbulence model was incorporated into the Lattice-Boltzmann computational method. The simulation results showed that the combined LBM-RANS provide a reasonably accurate description of the airflow behavior in the room at modest computational cost.
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Seta, Takeshi. "Particulate Flow Simulation by the Immersed Boundary Lattice Boltzmann Method." In ASME-JSME-KSME 2011 Joint Fluids Engineering Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/ajk2011-04008.
Abstract:
We demonstrate the applicability of the immersed boundary lattice Boltzmann method (IB-LBM) based on the implicit correction method to the simulation of rigid body motion in a viscous fluid and to the natural convection calculation. We compare the accuracy of the IB-LBM based on the implicit correction method with one of the IB-LBM based on the direct forcing method that eliminates the necessity of the determination of free parameters. In the simulations of the cylindrical Couette flow and of the heat transfer between two concentric cylinders, the implicit correction method indicates the first-order accuracy in the number of Lagrangian points. The accuracy of the IB-LBM based on the direct forcing method is independent of the number of the boundary points. The IB-LBM based on the implicit correction method is more accurate than one based on the direct forcing method.
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Seta, Takeshi, Kenichi Okui, and Eisyun Takegoshi. "Lattice Boltzmann Simulation of Nucleation." In ASME/JSME 2003 4th Joint Fluids Summer Engineering Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/fedsm2003-45163.
Abstract:
We propose a lattice Boltzmann model capable of simulating nucleation. This LBM modifies a pseudo-potential so that it recovers a full set of hydrodynamic equations for two-phase flows based on the van der Waals-Cahn-Hilliard free energy theory through the Chapman-Enskog expansion procedure. Numerical measurements of thermal conductivity and of surface tension agree well with theoretical predictions. Simulations of phase transition, nucleation, pool boiling are carried out. They demonstrate that the model is applicable to two-phase flows with thermal effects. Using finite difference Lattice Boltzmann method ensures numerical stability of the scheme.
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Vural, Yasemin, Suryanarayana R. Pakalapati, and Ismail B. Celik. "A Continuity Outlet Boundary Condition for the Lattice Boltzmann Method." In ASME 2012 Fluids Engineering Division Summer Meeting collocated with the ASME 2012 Heat Transfer Summer Conference and the ASME 2012 10th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/fedsm2012-72337.
Abstract:
A continuity outlet boundary condition for the Lattice Boltzmann Method (LBM) is proposed based on the assurance of the mass conservation of the system. The main advantage of the proposed boundary condition over the conventional Computational Fluid Dynamics (CFD) techniques is that the macroscopic properties, e.g. velocity, pressure etc. are not needed to be prescribed at the outlet, these properties are automatically calculated with the imposed boundary condition. This is especially useful in practice where the macroscopic properties at the outlet are difficult or impossible to be measured and described as in the biological flows. In order to test the feasibility of the proposed method, the LBM simulations are first verified for its capability to simulate flow in a symmetrically bifurcated channel. Then asymmetrically bifurcated geometries representing the blood vessels have been designed with different bifurcation angles. The new boundary condition is also tested for multi-component LBM simulations. For these cases, LBM predictions have been compared with the predictions for the commercial CFD software, namely ANSYS FLUENT at different Reynolds numbers. The results show that there is a good agreement between the LBM and FLUENT predictions, and this proves the capability of the proposed boundary condition as a viable method that can be used in practice.
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Kucinschi, Bogdan R., and Abdollah A. Afjeh. "Simulation of Flow in Thin Fluid Films Using the Lattice Boltzmann Method." In STLE/ASME 2008 International Joint Tribology Conference. ASMEDC, 2008. http://dx.doi.org/10.1115/ijtc2008-71112.
Abstract:
The present work deals with the application of the Lattice Boltzmann Method (LBM), which is a relatively new Computational Fluid Dynamics approach, to fluid film lubrication. LBM accounts for the inertia forces, while being easier to implement than Navier-Stokes solvers for complex geometric configurations. The LBM solution for a classic case is presented in comparison with the analytic Reynolds solution and the numeric solution obtained with Navier-Stokes solvers.
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Takada, Naoki, Akio Tomiyama, and Shigeo Hosokawa. "Lattice Boltzmann Simulation of Drops in a Shear Flow." In ASME/JSME 2003 4th Joint Fluids Summer Engineering Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/fedsm2003-45166.
Abstract:
In this paper, we present simulation results of two- and three-dimensional motions of drops in a shear flow based on the lattice Boltzmann method (LBM), where a macroscopic fluid flow results from averaging collisions and propagations of mesoscopic particles. The binary fluid model in LBM used here can reproduce two-phase interface in a self-organizing way by repulsive interaction between particles consistent with the van der Waals-Cahn-Hilliard free energy theory. A finite difference scheme is applied to the lattice-Boltzmann equations governing time evolution of velocity distributions of particle number density. When a drop is suspended in an immiscible second liquid with the same mass and viscosity between moving parallel plates, the numerical results of deformation of drop agree with theoretical solutions and previous numerical results obtained by the volume-of-fluid (VOF) method. Breakup motions of drops in LBM are also reasonable in comparison with the critical Reynolds and capillary numbers predicted by the VOF method. In the simulations of two-drop interaction, it is shown that the breakup motion depends on not only number density of drops but also initial positioning of their volumetric center away from a halfway cross section between the plates.
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Hsu, C. T., S. W. Chiang, and K. F. Sin. "A Novel Dynamics Lattice Boltzmann Method for Gas Flows." In ASME 2010 3rd Joint US-European Fluids Engineering Summer Meeting collocated with 8th International Conference on Nanochannels, Microchannels, and Minichannels. ASMEDC, 2010. http://dx.doi.org/10.1115/fedsm-icnmm2010-31237.
Abstract:
The lattice Boltzmann method (LBM), where discrete velocities are specifically assigned to ensure that a particle leaves one lattice node always resides on another lattice node, has been developed for decades as a powerful numerical tool to solve the Boltzmann equation for gas flows. The efficient implementation of LBM requires that the discrete velocities be isotropic and that the lattice nodes be homogeneous. These requirements restrict the applications of the currently-used LBM schemes to incompressible and isothermal flows. Such restrictions defy the original physics of Boltzmann equation. Much effort has been devoted in the past decades to remove these restrictions, but of less success. In this paper, a novel dynamic lattice Boltzmann method (DLBM) that is free of the incompressible and isothermal restrictions is proposed and developed to simulate gas flows. This is achieved through a coordinate transformation featured with Galilean translation and thermal normalization. The transformation renders the normalized Maxwell equilibrium distribution with directional isotropy and spatial homogeneity for the accurate and efficient implementation of the Gaussian-Hermite quadrature. The transformed Boltzmann equation contains additional terms due to local convection and acceleration. The velocity quadrature points in the new coordinate system are fixed while the correspondent points in the physical space change from time to time and from position to position. By this dynamic quadrature nature in the physical space, we term this new scheme as the dynamic quadrature scheme. The lattice Boltzmann method (LBM) with the dynamic quadrature scheme is named as the dynamic lattice Boltzmann method (DLBM). The transformed Boltzmann equation is then solved in the new coordinate system based on the fixed quadrature points. Validations of the DLBM have been carried with several benchmark problems. Cavity flows problem are used. Excellent agreements are obtained as compared with those obtained from the conventional schemes. Up to date, the DLBM algorithm can run up to Mach number at 0.3 without suffering from numerical instability. The application of the DLBM to the Rayleigh-Bernard thermal instability problem is illustrated, where the onset of 2D vortex rolls and 3D hexagonal cells are well-predicted and are in excellent agreement with the theory. In summary, a novel dynamic lattice Boltzmann method (DLBM) has been proposed with algorithm developed for numerical simulation of gas flows. This new DLBM has been demonstrated to have removed the incompressible and isothermal restrictions encountered by the traditional LBM.
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Fu, S. C., W. W. F. Leung, and R. M. C. So. "A Lattice Boltzmann Method Based Numerical Scheme for Microchannel Flows." In ASME 2008 International Mechanical Engineering Congress and Exposition. ASMEDC, 2008. http://dx.doi.org/10.1115/imece2008-67654.
Abstract:
Lattice Boltzmann method (LBM) has been recently developed into an alternative and promising numerical scheme for modeling fluid physics and fluid flows. The equation is hyperbolic and can be solved locally, explicitly, and efficiently on parallel computers. LBM has been applied to different types of complex flows with varying degree of success, but rarely to micro-scale flow. Due to its small scale, micro-channel flow exhibits many interesting phenomena that are not observed in its macro-scale counterpart. It is known that the Navier-Stokes equations can still be used to treat micro-channel flows if a slip wall boundary condition is assumed. The setting of boundary conditions in LBM has been a difficult task, and reliable boundary setting methods are limited. This paper reports on the development of an algorithm to solve the Boltzmann equation with a splitting method that allows the application of a slip wall boundary condition. Moreover, the fluid viscosity is accounted for as an additional term in the equilibrium particle distribution function, which offers the ability to simulate both Newtonian and non-Newtonian fluids. An LBM based numerical scheme, which is suitable for micro-channel flows, is proposed. A two-dimensional nine-velocity lattice model is developed for the numerical simulation. Validation of the numerical scheme is carried out against micro-channel, micro-tube and driven cavity flows, and excellent agreement is obtained between numerical calculations and analytical solutions of these flows.
Reports on the topic "LBM (Méthode de Lattice Boltzmann)":
1
Dawson, Leelinda, and Yansen Wang. Terrain and Urban Data Preprocessing System for the Atmospheric Boundary Layer Environment – Lattice Boltzmann Model (ABLE-LBM). DEVCOM Army Research Laboratory, October 2023. http://dx.doi.org/10.21236/ad1213050.