Abstract:
The lattice Boltzmann method-based LES (LBM-LES), a new fluid simulation method, owns the advantages of simpler algorithms and more significant computational speed compared to the finite volume method-based large-eddy simulation (FVM-LES); and therefore arouses wide attention in unsteady flow simulation. However, LBM-LES requires finer grids to achieve the same simulation accuracy as FVM-LES is due to the defects of Bounce-Back, LBM’s default wall boundary. This study introduces a new wall boundary that incorporates a wall function and can improve the simulation accuracy. We subsequently conduct an unsteady wind field simulation around a single building using LBM-LES and FVM-LES and show that WFB can make LBM-LES’s accuracy similar to FVM-LES when using the same grid resolution. In addition, results also indicate that LBM-LES’ computational speed and parallel computational efficiency are more significant, showing high potential in large-scale urban wind environments unsteady simulation.
