Numerical simulation of landslide generated impulse waves using a δ+-LES-SPH model

Abstract

In this article, a δ+-LES-SPH model is presented to study the generation and propagation of impulse waves. In this model, a density diffusion term is added to the continuity equation to eliminate the numerical high-frequency oscillation of the pressure field. A particle shifting technique is introduced and modified in the motion equation to improve the accuracy and robustness of the smoothed particle hydrodynamics (SPH) model. The physical viscosity term and the turbulence viscosity term based on the large eddy simulation (LES) are used in the momentum equation to calculate the viscous force. To predict the rigid slide motion more effectively, we propose a rigid slide motion model that considers friction in the δ+-LES-SPH frame. The δ+-LES-SPH code was implemented in Fortran 90, and OpenMP programming technology was used to improve the calculation efficiency. Subsequently, this parallel SPH code was used to simulate subaerial and submarine rigid landslides in 2-D and more realistic 3-D applications. The SPH results were compared with the experimental data and other numerical results. The results show that the proposed model has a good convergence and less numerical dissipation. Satisfactory results were obtained for the rigid slide motion, wave generation, and long-distance propagation.