Large eddy simulation of flow field and particle dispersion in a ventilated model room using a parallel lattice Boltzmann method

Abstract

The present paper addresses the use of a parallel lattice Boltzmann solver for large eddy simulation of particulate matter flow in a single ventilated model room. The formulation of lattice Boltzmann method (LBM), implementation of large eddy simulation (LES), description of finite volume method (FVM) and then integration of Lagrangian particle tracking in the present algorithm are outlined. A parallel processing method, known as decomposed domain method, for flow and particle phases is defined. Combined stream and collision step technique is employed to reduce CPU runtime and memory usage. The ultimate objective is validation and comparison of prediction accuracy and speed up between present LBM-LES results, FVM-LES results based on Navier–Stokes equations, and available experimental data. Results of flow field show acceptable accuracy for the present LBM-LES method when using high-resolution lattices. It is revealed that in order to achieve an accuracy almost equal to FVM, LBM requires twice the number of lattices but still provides a higher speed. Also, it is shown that the present model is well capable of predicting vortex core and vortex lines and it can capture the features and structure of the turbulence flow field reasonably well. In the particle field, it can capture concentration patterns and particle dispersion with an admissible discrepancy. The use of presently developed algorithm dramatically reduces computational time, such that speed can increase by up to four times in flow and eight times in particle simulations.

Copyright © 2023 American Association for Aerosol Research

Graphical Abstract

Editor:

• Jing Wang