CFD-DEM Coupling Of Dense Liquid-solid Two-phase Flow Application Of The Method In CMP

Dense liquid-solid two-phase flow is an important and cutting-edge research field in granular fluid systems.With the rapid development of computer technology,numerical simulation methods have become a powerful tool for studying dense particle liquid-solid two-phase flow.The Euler-Eulerian model(TFM,two-fluid model)based on the Euler method and the Euler-Lagrange model(CFD-DEM,computational fluid dynamics-discrete element method)based on the Lagrange method are The main numerical simulation methods of this type of liquid-solid flow system are currently described.Because the CFD-DEM method can track the motion information of a single particle,it can also consider the particleparticle,particle-wall collision and particle-fluid interaction,which has attracted the attention of many scholars.At present,people do not know much about the phenomena and processes in fluid-solid two-phase flow.The most fundamental reason is that they do not understand the mechanism of action between fluid-solid two-phase flow.Their research is still mainly based on simple experimental observations and through experiments.Data construction empirical formula.Experimental research and theoretical research have great limitations.It is generally believed that numerical simulation can supplement some of the deficiencies in experimental and theoretical research,and has gradually become a widely accepted research method.In the first step of this paper,a direct numerical simulation model of turbulence is established,and the simplified model is used to replace the circular plane to study its complex turbulent flow behavior.In the second step,a liquid-solid two-phase coupling model based on Euler-Lagrange's idea is established.The method of coupling computational fluid dynamics(CFD)and discrete element method(DEM)is used to calculate the impact force of the particles and the constraint surface The size characterizes the degree of wear on the constrained surface,simulates the chemical mechanical polishing(CMP)process,and studies the particle motion behavior and wear due to particle impact in a complex flow field.In this paper,we use the method of numerical simulation to study the chemical mechanical polishing process.Through the influence of the rotation speed of the wafer and polishing pad,the volume fraction of solid particles and the particle size on the surfaceremoval rate of the silicon wafer,some phenomena in chemical mechanical polishing are carried out.Explanation.This result can provide a basis for the optimization of the parameters of the chemical mechanical polishing process in the future.