CAJ | 학술논문

基于 FLUENT 软件的 MPI 平台，在二次开发框架内通过用户自定义函数文件实现了CFD-DEM耦合并行算法。该并行算法具有随CPU核数增加的较佳扩展性能和良好加速性能。通过构建空隙率标量场、重组基于局部平均并考虑气固相互作用的气相控制方程，提高了气相控制方程的求解稳定性与收敛性；通过软球模型确定颗粒颗粒及颗粒壁面间的相互作用，以曳力模型为基础建立了相间相互作用关系。将该CFD-DEM耦合并行模型应用于锥形喷动床气固两相流动的数值模拟中，结果表明：该CFD-DEM耦合并行模型能较好地模拟锥形喷动床内气固流动行为；锥形喷动床内的颗粒流动经历了鼓泡阶段和稳定流态化阶段；在稳定流态化阶段，物料流动具有明显的周期性。基于锥形喷动床内颗粒相的瞬时速度场，获得了稳定流态化阶段颗粒的时均速度分布规律。
기우 FLUENT 연건적 MPI 평태，재이차개발광가내통과용호자정의함수문건실현료CFD-DEM우합병행산법。해병행산법구유수CPU핵수증가적교가확전성능화량호가속성능。통과구건공극솔표량장、중조기우국부평균병고필기고상호작용적기상공제방정，제고료기상공제방정적구해은정성여수렴성；통과연구모형학정과립과립급과립벽면간적상호작용，이예력모형위기출건립료상간상호작용관계。장해CFD-DEM우합병행모형응용우추형분동상기고량상류동적수치모의중，결과표명：해CFD-DEM우합병행모형능교호지모의추형분동상내기고류동행위；추형분동상내적과립류동경력료고포계단화은정류태화계단；재은정류태화계단，물료류동구유명현적주기성。기우추형분동상내과립상적순시속도장，획득료은정류태화계단과립적시균속도분포규률。
Based on MPI (Message Passing Interface)platform of FLUENT software,the parallel technique for coupled CFD (computational fluid dynamics)-DEM(discrete element method)model is implemented by user defined functions in the framework of secondary development,which has good scalability and acceleration performance with the increase of CPU number.The convergence of the governing equations is improved by constructing the void fraction scalar field and reorganizing the governing equations of the gas phase which follow the volume-averaged form of the two-fluid mod-el.Inter-particle and particle-wall interactions are determined with the soft-sphere model and the two phases are coupled based on the drag model.The parallel coupled CFD-DEM model is applied to the simulation of gas-particle two-phase flow in a conical-base spouted bed.Simulation results show that this model could well simulate gas-flow behavior in the spouted bed.Two distinct regions can be identified:the start-up and stable fluidization stage.In the stable fluidization stage,an oscillation cy-cle period can be observed,and the characteristics of the time-averaged particle velocity are obtained on the basis of the instantaneous particle velocity field.