非球形颗粒流的模拟程序开发及其对颗粒射流的模拟

项目名称： 非球形颗粒流的模拟程序开发及其对颗粒射流的模拟

项目编号： No.11472083

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 黄骏

作者单位： 复旦大学

项目金额： 78万元

中文摘要： 液滴冲击液面过程会形成飞溅射流，即Worthington 射流. 和液体相比，颗粒材料没有表面张力，但也会有类似的现象发生.显然由于粒子特性差异，如形状、回弹系数、表面摩擦等会影响射流的形态. 本项目希望通过数值模拟和实验相结合的方法， 以研究因为冲击造成不同性质的颗粒飞溅的不同表现为切入点, 研究非球形颗粒微观表现和宏观表现间的联系,同时编写一套用于复杂颗粒流计算的程序. 其中颗粒相采用离散元方法(DEM)模拟，而周围流体采用基于无网格的SPH或者其他CFD方法模拟，并且将两者的作用力双向耦合起来.同时将颗粒相内相互作用从球形粒子接触模型扩展到非球形粒子接触.由于复杂情况下(比如三维模拟下)颗粒数目巨大，拟采用 GPU 加速来求解.所编写程序除模拟射流外，今后还可用于其他领域，比如流场中颗粒的沉降分离.最后，申请人希望在 GNU 协议下将所开发程序开源.

中文关键词： 非球形颗粒；离散元模型；光滑粒子水动力法；GPU；仿真；粒子喷溅

英文摘要： Worthington jets, namely narrow vertical jets, are produced by the impacting liquid drops upon puddles surface. Similar narrow jets occur even for granular materials, where surface tension is absent. Obviously, the composition of these particles, e.g. shape, coefficient of restitution, surface roughness, density and so on, may affect the jet. This program is planned to discover the relationship between the macroscopically behavior and microscopically behavior by studying this kind of behavior in granular jets composed of non-spherical particles by both simulations and experiments. In addition, a program for complex granular flow will be set up via this program. Discrete element method (DEM) will be employed for the simulation of solid phase and SPH (smoothed particle hydrodynamics) a meshless method for the surrounding fluid phase. In addition, these two phases will be coupled in the simulations. In addition, the shape of the particles will be developed from spherical to non-spherical. As particle number, in 3D simulations, is huge, GPU technic will be used to speed the simulations. Excluding the simulations of granular jet, the codes can be used in other fields， e.g. the suspention of solid particles from liquid and so on. Lastly, the applicant want to release his previous codes and the new codes as free and open software under GNU general public License.

英文关键词： non-spherical particles;discrete element model;smoothed particle;GPU simulation;ranular jet