Towards a hybrid parallelization of lattice Boltzmann methods

AbstractOngoing research towards the development of a hybrid parallelization concept for lattice Boltzmann methods is presented. It allows coping with platforms sharing both the properties of shared and distributed architectures. The proposed approach relies on spatial domain decomposition where each domain represents a basic block entity which is solved on a symmetric multi-processing (SMP) system. Emphasis is placed on the software design and the reworking needed to achieve good performance using OpenMP in that context. Those ideas are implemented in the C++ project OpenLB, which is also sketched in this article. The efficiency of the proposed approaches is tested on a 3D benchmark problem and compared with a purely MPI based approach

Développement d'algorithmes parallèles pour la simulation d'écoulements de fluides dans les milieux poreux

Problématique de la mécanique des fluides numérique en milieu poreux -- Méthode de Boltzmann sur réseau -- Origines -- Principe de la méthode -- Implantation numérique de MBR-BGK -- Réduction de la mémoire utilisée par MBR-BGK -- Amélioration de la performance de calcul de MBR-BGK -- Méthodes de MBR-BGK adaptatives -- Aspects parallèles de la méthode de Boltzmann sur réseau -- Contenu parallèle -- Communications -- Équilibrage de tâches -- Résumé et objectifs spécifiques -- On improving the performance of large parallel Lattice Boltzmann flow simulations in heterogeneous porous media -- The Lattice Boltzmann method -- Data structure and memory usage optimization -- Parallel workload balance & communication strategies -- Numerical experiments -- Conclusions and perspectives -- Development of theoretical parallel performance models for heterogeneous porous media -- A parallel workload balanced and memory efficient Lattice-Boltzmann algorithm with single unit BGK relaxation time -- LBM implementation, data structure and memory requirements -- Parallel workload balance & communication strategies -- Results and discussions -- Concluding remarks -- Effect of particle size distribution and packing compression on fluid permeability as predicted by Lattice-Boltzmann simulations

Fluid Flow Simulation and Optimisation with Lattice Boltzmann Methods on High Performance Computers - Application to the Human Respiratory System

An overall strategy for numerical simulations of the full human respiratory system is introduced. The integrative approach takes advantage of numerical simulation, high performance computing and newly developed mathematical optimisation techniques, all based on a mesoscopic model description and on lattice Boltzmann methods as discretisation strategies. Validated numerical results are presented for the simulation of respirations in a real human lung and nose geometry captured by CT

An Object Oriented Approach to Lattice Gas Modeling

We present a parallel library which can be used for any lattice gas (LG) application. A highly reusable implementation, as well as a general parallelization scheme, based on a graph partitioning technique are developed. We show that the performance we obtain with our approach compares favorably with the plain, classical implementation of LG models on regular domains and can be even better for irregular domains. We propose a theoretical expression for the execution time and we validate our analysis in the case of a specific application, namely wave propagation in urban areas. 1 Introduction The lattice gas (LG) technique is a fast developing numerical tool aimed at simulating, on a computer, various physical phenomena such as complex fluid flows, reaction-diffusion systems or wave propagation processes [1, 2, 3]. In the present terminology, LG systems consist of cellular automata models known as lattice gas automata and lattice Boltzmann methods (LB) that are now viewed as serio..