A WCSPH two-phase mixture model for tsunami waves generated by granular landslides

Abstract

An advanced weakly compressible smooth particle hydrodynamics (WCSPH) two-phase mixture model is developed in this study to simulate the motion of granular landslides as well as their resulting tsunami waves. The governing equations of fluid and granular phases are established based on the two-phase mixture theory. The granular phase is assumed to be a weakly compressible non-Newtonian fluid, and the regularized visco-inertial rheology model is adopted to calculate its effective viscosity. The water phase is considered as a weakly compressible Newtonian fluid, and the large eddy simulation (LES) turbulence model is adopted to describe the turbulence effect of the fluid. The interphase force controls the momentum exchange between fluid and granular phases. The artificial diffusion term and particle shifting technique are adopted to improve the accuracy and stability of numerical calculation. This developed numerical model was applied to simulate submarine and subaerial granular landslide-tsunamis, and the results were compared with corresponding experimental data. The results show that the current model can adequately represent the generation and propagation of tsunami waves and the motion and deformation of granular landslides. Compared with the traditional two-phase granular flow models, the current model has higher accuracy and wider application scenarios.