考虑粒间滚动阻力的CFD-DEM流-固耦合数值模拟方法

发布时间：2018-06-20 23:13

  本文选题：CFD + DEM　； 参考：《岩土力学》2017年06期

【摘要】：在离散元(DEM)和计算流体动力学(CFD)程序基础上,运用流-固相互作用力方程建立三维CFD-DEM细观耦合数值模拟模型。CFD-DEM的控制方程包括流体-颗粒相互作用力方程、CFD的流体和DEM的颗粒运动方程。其中,考虑到土颗粒的形状效应,引入颗粒滚动阻力机制,介绍了适用性较强的滚动阻力模型。在开源耦合程序CFDEM的框架下,定制CFD开源程序Open FOAM与DEM开源程序LIGGGHTS之间的双向耦合,实现基于颗粒细观的流-固耦合计算。通过砂堆和砂土渗流的模拟分别验证了所嵌入的滚动阻力模型的有效性及耦合模型的可行性。模拟结果表明,圆柱土体中向上渗流流速与水力梯度关系与经典的Ergun理论解接近;耦合模型中所引入的颗粒间滚动阻力模型能够很好地反映颗粒形状对砂堆形成休止角和土体堆积孔隙率的影响。
[Abstract]:On the basis of discrete element design (DEM) and computational fluid dynamics (CFD) programs, Using the fluid-solid interaction force equation, the three-dimensional CFD-DEM mesoscale coupled numerical simulation model. The governing equation of CFD-DEM includes fluid and particle motion equations of CFD and Dem. Considering the shape effect of soil particles, the rolling resistance model is introduced. In the framework of open source coupling program CFDEM, the bidirectional coupling between open FOAM of CFD and LIGGHTS of Dem open source program is customized to realize fluid-solid coupling calculation based on particle meso. The effectiveness of the embedded rolling resistance model and the feasibility of the coupling model are verified by the simulation of sand pile and sand seepage respectively. The simulation results show that the relationship between the upward seepage velocity and the hydraulic gradient in the cylindrical soil is close to the classical Ergun theoretical solution. The rolling resistance model introduced in the coupling model can well reflect the effect of particle shape on the angle of repose formation of sand pile and the accumulation porosity of soil.
【作者单位】： 海岸和近海工程国家重点试验室大连理工大学;岩土力学研究中心诺丁汉大学;
【基金】：国家自然科学基金青年基金(No.51409036);国家自然科学基金(No.51179023)~~
【分类号】：TU43
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本文编号：2046056