Research And Simulation Of Incompressible Flow Based On MPS Method

With the rapid development of science and technology of the information society, People demand more and more higher on visual:The exciting visual effects floods, waves, eddies in the film; spacecraft flight in the space; air movement in the rain snow, wind and other natural scene simulation; event of natural disasters on buildings and human impact and the real effect of the degree of injury simulation; real physical scenes rain, fountains, Piao, smoke and other effects of computer visualization simulation are important research topic in Computational Fluid Dynamics.The so-called computational fluid dynamics is to use computers and numerical methods discrete number of physical phenomena including fluid flow, heat transfer, mass diffusion phenomena such as numerical analysis and simulation of a new discipline. This discipline in the engineering and scientific fields has been widely used.This numerical simulation method the fluid has many advantages in terms of experimental methods:Numerical simulation of fluid can be difficult to control experimental system; to exceed the limits of human behavior, research and risk and under the conditions of non-human systems; can greatly reduce design time and costs; and the freedom and flexibility of its operation, can provide an unlimited amount of research results in detail.Computational fluid dynamics to understand the research methods,we must first understand the nature and classification of the basic equations of fluid dynamics. The basic equations of fluid mechanics was build by C.-L.-M.-H Navier and GG Stokes by the first half of the 19th century, referred to as N-S equations. Numerical methods for solving the equations and non-grid method can be divided into two grid method.In this paper, we introduce a meshless methods - moving particle semi-implicit (MPS) method.First, the paper describes the moving particle semi-implicit (MPS) method of the theoretical model and numerical solution procedure, the method is a numerical method based on Lagrange point of view. Fluid is that a limited number of mobile particles, these particles also carry the material properties, external and internal forces at the interaction of movement. Equations of particle interactions in the model expressed by the gradient model, Laplace model and the free surface model based on the discrete derived. Not need to create the grid, therefore, not subject to distortion of the grid for the water simulation with large deformation mechanics. MPS differs from the other particle methods, such as the weak compressible SPH method is to use the model to approximate incompressible fluid flow problems. The main features of MPS method is to introduce the concept of the particle number density, the fluid does not provide the basis for compression card, so that MPS method has become a real incompressible fluid simulation of the problem. MPS Act also introduced a semi-implicit algorithm, effectively maintain the incompressibility of the fluid. And the Lagrange description of the method is completely, there is no value for the formation of convective diffusion. And the article also details the neighborhood search method particles, and with traditional search methods were compared.Second, in terms of energy conservation in the MPS method a detailed analysis, such as linear momentum, angular momentum conservation issues. To address this issue, the paper also outlined a method to improve MPS method (CMPS method), improved CMPS Law Act so that the whole calculation process to better meet the linear momentum and angular momentum conservation.In addition, this article by using the MPS method were done some numerical simulation experiments. Three-dimensional simulation of a single drop of water and two-dimensional visualization break phenomena, simulation results are realistic stronger method is proved effective in simulation of high.