基于Semi-resolved CFD-DEM的跨尺度颗粒流体两相耦合模型的研究  

Research on the cross-scale particle-fluid two phase coupling model based on Semi-resolved CFD-DEM

作　　者：丁旺 薛雷平[1] DING Wang;XUE Lei-ping(MOE Key Laboratory of Hydrodynamics,School of Naval Architecture,Ocean and Civil Engineering,Shanghai Jiao Tong University,Shanghai 200240,China)

机构地区：[1]上海交通大学船舶海洋与建筑工程学院教育部水动力学重点实验室,上海200240

出　　处：《水动力学研究与进展（A辑）》2021年第5期705-716,共12页Chinese Journal of Hydrodynamics

摘　　要：CFD-DEM模型被广泛应用于颗粒流的模拟中,同时两相耦合强烈依赖于流体网格分辨率。根据网格长度与颗粒直径的比值(网格粒径比),CFD-DEM模型被分为三类:Resolved、Un-resolved和Semi-resolved。该文结合Semi-resolved与Resolved模型,提出了一种适用于跨尺度颗粒与流体耦合的方法。通过单颗粒沉降和液固流化床的模拟,分析对比了在Semi-resolved模型中,四种常用的拖曳力模型的计算精度。结果表明,使用Gidaspow拖曳力模型模拟的结果与实验结果最为吻合,并在此基础上验证了考虑颗粒受到的虚拟质量力能够进一步修正模拟结果。最后基于Gidaspow拖曳力模型,并考虑虚拟质量力的影响,通过混合跨尺度颗粒与流体耦合的算例,验证了Semi-resolved与Resolved模型相结合的跨尺度颗粒模拟方法的可行性。CFD-DEM model is widely used in the simulation of particulate flow,and the two phase coupling strongly depends on the resolution of fluid grid.According to the ratio of grid length to particle diameter(grid-diameter ratio),CFD-DEM models are divided into three categories:Resolved,Un-resolved and Semi-resolved.In this paper,a method for cross-scale particle-fluid coupling is proposed by combining the Semi-resolved and Resolved models.Through the simulation of single particle sedimentation and liquid-solid fluidized bed,the calculation accuracy of four commonly used drag force models in the Semi-resolved model is analyzed and compared.The results show that the simulation results of the Gidaspow drag force model are most consistent with the experimental data,and on this basis,it is verified that the simulation results can be further modified by considering the virtual mass force on particles.Finally,based on the Gidaspow drag force model and considering the influence of virtual mass force,the feasibility of the cross-scale particle simulation method combining the Semi-resolved and Resolved model is verified by a mixed cross-scale particle-fluid coupling example.

关 键 词：CFD-DEM 颗粒流 虚拟区域法 跨尺度 拖曳力模型 虚拟质量力 

分 类 号：O359[理学—流体力学]