Study on solid block landslide generated tsunami using a modified δ-les-SPH model

Abstract

This article established a weakly compressible smoothed particle hydrodynamics (WCSPH) model to simulate the single- and multi-block landslide-tsunamis. This WCSPH model was developed based on the δ-LES-SPH method according to the characteristics of landslide-tsunamis. In this model, a modified coupled dynamic boundary method was proposed to mimic (in a uniform manner) the solid wall boundary of the fluid and the dynamic friction boundary of the slide, which expands the range of application of the δ-LES-SPH method. A particle shifting technique (PST) was introduced to improve the accuracy and robustness of the δ-LES-SPH method. The Fortran 90 language was used to implement the current SPH code, and OpenMP programming was adopted to improve the computing efficiency. Afterwards, the current procedure was utilized to model subaerial and submarine single-block rigid landslides and submarine multi-block landslides. Firstly, the SPH results of the slide movements, wave profiles and energy were compared with the experimental data and previous numerical results. Then, the energy equation is used to study the energy components of different types of landslide-tsunamis. Energy analysis reveals that the more complex the movement of the slide, the lower the efficiency of energy transfer. The consistency between the numerical results and the experimental data confirms the effectiveness and stability of the proposed method. The current model provides a useful tool to study the problem of tsunamis generated by rigid landslides.