基于格子玻尔兹曼方法的自仿射粗糙裂隙渗流模拟

Self-affine Rough Fracture Flow Simulation Based on the Lattice Boltzmann Method

基于格子玻尔兹曼方法模拟研究了自仿射粗糙裂隙的渗流特征.通过连续随机叠加技术,生成了不同粗糙指数的自仿射粗糙裂隙.为验证格子玻尔兹曼方法,将格子玻尔兹曼结果与泊肃叶流解析解对比.通过格子玻尔兹曼方法与自仿射粗糙裂隙技术的结合,成功模拟了粗糙裂隙内部的流场分布,并分析了粗糙裂隙内部的渗流路径与水力等效隙宽的变化.结果表明,不均匀的隙宽分布对裂隙的流场分布影响较大;尽管两组裂隙内部的Re一致,但其最大流速有一定差异.

The self-affine rough fracture seepage feature is studied by lattice Boltzmann method.A selfaffine rough fracture with different indices is generated through continuous random stacking technique.To verify the lattice Boltzmann method,the results of lattice Boltzmann and analytical solution of Poiseuille flow are contrasted.By combining self-affine rough fracture technique and lattice Boltzmann method,the flow field distribution inside the rough fracture is simulated successfully,and the rough fracture seepage path inside the hydraulic equivalent gap width changes is analyzed.The results show that the uneven distribution of gap width has greater impact on the fracture flow field distribution.Despite Re number inside the rough fracture is consistent,there are some differences in the maximum flow rate between two fractures.