ASSESSMENT OF A LATTICE BOLTZMANN MODEL TO SIMULATE FLUID FLOWS WITH COMPLEX GEOMETRIES

Lately, the lattice Boltzmann method (LBM) has proven to be a promising approach to solve complex fluid flows and transport phenomena. In the present contribution, the LB-BGK model, also called single relaxation time (SRT), is used to handle fluid flows in complex geometries. The model is first benchmarked via the 2D Poiseuille flow problem to conduct a discussion on its accuracy and performance. The accuracy of the LBM is weighted by several factors; among these we investigated the effect of the boundary conditions, the spatial resolution, the Mach number, and the choice of relaxation factors. It is found that the considered LBM is highly dependent on the physical problem, the numerical implementation, and the used parameters. However, a set of correlated optimal parameters is suggested to improve the accuracy and decrease both discretization and compressibility errors. In addition, we discussed the ability of the current model to handle complex geometries. The simulation of fluid past a circular or square cylinder in a confined geometry has been successfully achieved, even when curves are modeled as stairs. In light of the obtained results, we can state that the proposed model has high potential to handle problems with complex flows and geometries.