Study On Boundary Treatment And Liquid Surface Tension In Fluid Simulation

As an important Branch of computer graphics,fluid simulation has been widely used in many fields such as special effects,military simulation,animation and medicine.The treatment of boundary and liquid surface tension in fluid simulation has always been the focus of fluid simulation.Therefore,it is of great practical value to study how to deal with the boundary and surface tension in fluid simulation.This thesis first introduces the history of boundary treatment and the study of liquid surface tension in fluid simulation,as well as the research status at home and abroad.Then the following four aspects of work were carried out in response to the above problems.Solid wall virtual particle method is the main method of fluid-solid coupling boundary treatment,but the calculation of this method is relatively large and there will be fluid particles passing through solid boundaries.In order to solve the above problems,the damping zone is set in the area near the boundary with two adaptive solid wall virtual particle sampling algorithms,which ensures that the fluid particles do not penetrate the solid boundary and improves the efficiency of simulation.In the traditional free surface fluid simulation method,the calculation of adding air particles is large.For solving this problem,a new method of air particle generation and adaptive step size for air particle regeneration is proposed.Compared with the traditional method,this method can greatly improve the efficiency of simulation without reducing the simulation effect.In the simulation of liquid surface tension,the traditional CSF surface tension algorithm is difficult to smooth the liquid surface.In this thesis,the traditional CSF surface tension algorithm is improved by adding the tangential force on the liquid surface on the basis of the liquid surface tension.The simulation results show that the fluid surface is smooth enough to be simulated by the improved CSF surface tension algorithm.In addition,the traditional Marching-cubes surface reconstruction algorithm uses equal size cells to divide the fluid simulation area,which results in a large amount of computation.In this thesis,an improved Marching-cubes algorithm is given to divide the fluid simulation region through different size cells,so as to accelerate the extraction of fluid surface.