A comparative analysis on the effect of two SPH schemes on suppressing pressure oscillation

Abstract

[Objectives] With the traditional smoothed particle hydrodynamics method, there is pressure oscillation in the flow field when simulating hydrodynamic problems involving free surfaces. In order to find out an effective algorithm to suppress pressure oscillation,the effects of two density diffusive algorithms, consisting of density re-normalization and density dissipation on suppressing pressure oscillation,are compared.[Methods] In this paper,a program to quantitatively measure wave elevation was employed and the effects of motion speed on these two algorithms were considered. The sloshing problems were simulated by using these two algorithms,respectively,and the pressure of one point within the fluid field and the wave elevation of the free surface were plotted at different angular velocities.[Results] By comparing the results obtained by the two algorithms,it was found that algorithms with a diffusive term when the coefficient is 0.05 can effectively suppress the pressure oscillation and obtain a more stable pressure and smoother free surface profile at different angular velocities. At a lower angular velocity,the density re-normalization algorithm does not express very well. At a higher angular velocity,both the two algorithms express very well,and suppress the pressure oscillation.[Conclusions] This conclusion makes a considerable contribution to engineering。

Keywords

• smoothed particle hydrodynamics(sph)
• pressure oscillation
• density re-normalization
• density diffusive