A Numerical Investigation Into the Impact Pressures of Different Base Forms Using SPH Method

Abstract

In this paper, the impact pressures of two different base forms are comparatively studied using Smoothed Particle Hydrodynamics (SPH) method. It is summarized from previous works that the improved weakly compressible SPH model shows better performances than incompressible SPH model in numerical simulations of free surface flows accompany with large deformations and strong discontinuities. Such advantages are observed in numerical accuracy, stability and efficiency. The weakly compressible SPH model used in this paper is equipped with some new correction algorithms, among which include the density reinitialization algorithm and a new coupled dynamic Solid Boundary Treatment (SBT) on solid boundaries. The new boundary treatment combines the advantages of both the repulsive boundary treatment and the dynamic boundary treatment, intending to obtain more stable and accurate numerical results. A benchmark test of dam breaking is conducted to prove the reliability of the numerical model used in this paper. Two representative cases, among which one has one cavity and the other one has three cavities, are numerically investigated and compared to support the conclusion that the base form with cavities generally experience lower local and overall impact pressures than the base form of flat plate. It is found that with the application of cavities on the bottom, the peak values of the boundary pressure near central bottom significantly decrease, leading to smaller force load and better structural stability. The mechanisms of such phenomenon might be the pressure absorption effect conducted by the cavities.