Lattice Boltzmann simulation of wind-driven rainfall on a slope surface

Abstract

In overland flow modeling, the influences of the slope degree, rain intensity and wind condition can be significant. In this study, the effects of the slope gradient and wind-driven rain were integrated in a nonlinear shallow water model based on the lattice Boltzmann method (LBM). Since slope gradient and wind condition can not only affect the flow rate, but also its momentum, we enhanced the mathematical model and derived two LBM schemes that include their hydrodynamic influence on the surface flow. Then, this model was verified by several typical cases. The results indicated that the momentum component of rainfall should be considered during the overland flow simulation influenced by wind, otherwise it would result in an intrinsic error of approximately [Formula: see text] in simulated results.