气体动理学格式模拟多孔介质流动的可行性

Feasibility of Simulation on Flow in Porous Media with Gas Kinetic Scheme

将气体动理学格式(GKS)拓展到模拟多孔介质内的低速渗流,并检验在孔隙尺度上模拟不可压缩低速流动的可行性与有效性.结果表明:GKS具有二阶空间精度,能够较精确地计算多孔介质的渗透率;相比于单松弛格子玻尔兹曼方法,GKS能够精确实现壁面无滑移边界条件,从而正确反映渗透率与黏性无关的特性;对于Berea砂岩切片结构中的复杂流动,模拟结果与实验吻合较好,能较精确地计算渗透率.给出GKS模拟达西渗流的马赫数选取准则,为研究多孔介质流动提供新的工具.

We extend gas kinetic scheme(GKS)to low-speed porous media flow,and test feasibility and effectiveness of the method.It shows that GKS is second-order accurate in space and is capable of predicting permeability of porous media.Compared with singlerelaxation-time lattice Boltzmann method,GKS implements precisely no slip boundary condition,thus reflects correctly characteristics of viscosity-independent permeability.For complex flow in Berea sandstone slice structure,simulation results are in good agreement with experimental data,and permeability is calculated accurately.A criteria of Ma number in GKS is proposed for Darcy flow.It shows that GKS could be a promising scheme for porous media flows.