Stability And Detail Improvement Of Implicit SPH Fluid-solid Interaction Method

Fluid-solid interaction simulation has always been a hot research problem in computer graphics.Drawing a more realistic and natural fluid-solid interaction scene is the goal of many researchers.Due to the flexible and changeable motion of fluid,a lot of calculations need to be performed in the process of fluid-solid interaction.But a large numerical error will affect the stability of the interaction,resulting in unrealistic visual effects.In addition,fluid surface details produced by the interaction are easily lost during rendering.Therefore,aiming at the problems of stability,reality and poor performance of fluid details in the fluid-solid interaction method,an improved implicit smooth particle hydrodynamics(SPH)fluid-solid interaction method is proposed.Firstly,in order to show the real motion state of the fluid,the Navier-Stokes equation satisfying the fluid incompressibility condition is used as the basic equation for the construction of the fluid motion model.Meanwhile,in order to ensure the incompressibility of the fluid,Divergence-Free SPH method is introduced to replace the traditional SPH method to solve the equation of motion of the fluid,which reduces the density and divergence errors of the calculation process,and realizes the creation of an incompressible fluid model efficiently and stably.Secondly,the volume maps method is introduced to deal with the solid boundary during fluid-solid interaction,and the boundary is represented by an implicit function without the need for particle sampling to avoid artificial friction.The boundary volume is discretized and stored in advance before calculation to improve the efficiency of boundary processing.Aiming at the numerical error in the boundary calculation,Moving Least Squares is introduced to interpolate the pressure on the solid boundary,and the calculation result is more accurate than the pressure mirror method.It is combined with the volume maps method to reduce the errors in the calculation of pressure and pressure gradient,and improve the stability of fluid-solid interaction.Then,in order to optimize the fluid details after the fluid-solid interaction and improve the reality,the particle resampling method is introduced to refine the fluid surface,which fully shows the different particle characteristics of the fluid surface area and enriches the details of the fluid-solid interaction.At the same time,the surface reconstruction process is improved and optimized to efficiently generate smooth fluid surfaces.Finally,the basic environment of the fluid-solid interaction system is built,and multiple experimental scenarios are designed.By analyzing and comparing the experiments,the effectiveness of the improved fluid-solid interaction method is verified.