Hybrid Lattice-Boltzmann/Level-set Method for Liquid Simulation and Visualization

The particle level set method (PLSM) and the lattice Boltzmann method (LBM) have been two major physics-based liquid simulation techniques used in computer graphics to generate splendid and dynamic visual effects. PLSM suffers from a high computational cost which arises from the global pressure correction step whereas LBM requires a large amount of memory to store distribution functions. In this work, we propose a hybrid lattice Boltzmann method (HLBM), which integrates PLSM and LBM, to visualize realistic liquid motion with emphasis on the behavior of the liquid-gas interface. HLBM first runs the LBM solver, computes macroscopic velocities, and extrapolates the velocity field to the gas region. Subsequently, the level set function and particles are advected by the extrapolated velocity field, and advected particles are used to correct errors in the level set function based on PLSM. Finally, the density difference between LBM and PLSM solvers is added to the distribution functions to correct the errors of LBM. We test the method for the broken dam and the water drop simulations. The results show that HLBM improves the quality of the fluid simulation without increasing the number of grids. Compared to the simulation using LBM with a grid resolution of 3 50 , the mean of the geometrical distance from the ground truth is 21.70% and 13.02% less using HLBM with the same number of grids, for the water drop and the broken dam simulations, * Corresponding Author. Email: [email protected]. International Journal of Computational Science 1992-6669 (Print) 1992-6677 (Online) www.gip.hk/ijcs © 2009 Global Information Publisher (H.K) Co., Ltd. All rights reserved. GLOBAL INFORMATION PUBLISHER 1 respectively. The simulation results also show that HLBM offers more splashy and dynamic visual effects than LBM without increasing the grid size.