基于格子Boltzmann方法的岩体单裂隙面渗流特性研究
发布时间：2018-07-16 13:40
【摘要】：为了研究层流状态下粗糙单裂隙面的渗流特性,基于格子Boltzmann方法,建立了压力作用下单裂隙面渗流的数值模型。采用D2Q9模型模拟离散速度分布方向,在宏观尺度上,上、下边界设置为不透水边界(u_x=u_y=0),左、右边界为压力边界(左侧压力p_(in)大于右侧压力p_(out))在微观尺度上,左、右边界及光滑裂隙表面采用非平衡态外推格式,粗糙裂隙表面采用标准反弹格式。编制了相应的计算程序,验证了光滑平板裂隙流的立方定律。采用分段随机裂隙长及裂隙宽的方法生成了粗糙裂隙面,并基于格子Boltzmann方法研究了不同粗糙裂隙面方案的渗流特性。研究结果表明:对于粗糙裂隙面,渗流特征极大程度取决于裂隙表面形貌,随着相对粗糙度的增加,裂隙渗流规律明显偏离立方定律。为此,考虑裂隙面相对粗糙度的影响,根据不同裂隙粗糙面方案的数值计算结果,提出了层流状态下粗糙裂隙面渗流的立方定律修正公式,为系统研究复杂粗糙裂隙的水力特性奠定了一定的基础。
[Abstract]:In order to study the percolation characteristics of rough single fracture surface in laminar flow, a numerical model for the seepage of fracture surface under pressure action is established based on the lattice Boltzmann method. D2Q9 model is used to simulate the direction of discrete velocity distribution. On macroscopic scale, the lower boundary is set as impermeable boundary (u_x=u_y=0), the left and right boundary is pressure boundary (left pressure p _ (in) is larger than right side pressure p _ (out) on microscopic scale, left, left). The non-equilibrium extrapolation scheme is used on the right boundary and smooth fracture surface, and the standard rebound scheme is used on the rough fracture surface. The cubic law of smooth slab fissure flow is verified by the corresponding calculation program. Based on the lattice Boltzmann method, the percolation characteristics of different rough fracture surface schemes are studied by using the method of segment random fracture length and crack width. The results show that the percolation characteristics of rough fracture surface depend on the fracture surface morphology to a great extent. With the increase of relative roughness, the law of fracture seepage deviates from the cubic law obviously. Therefore, considering the influence of the relative roughness of the fracture surface, according to the numerical results of different fracture rough surface schemes, the cubic law correction formula for the seepage of the rough fracture surface under laminar flow is proposed. It lays a foundation for the systematic study of hydraulic characteristics of complex rough fractures.
【作者单位】： 昆明理工大学建筑工程学院;中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室;
【基金】：国家自然科学基金资助(No.51408284.No.51508253,No.U1502231) 云南省应用基础研究计划项目(No.2016FB077)~~
【分类号】：TU45
[Abstract]:In order to study the percolation characteristics of rough single fracture surface in laminar flow, a numerical model for the seepage of fracture surface under pressure action is established based on the lattice Boltzmann method. D2Q9 model is used to simulate the direction of discrete velocity distribution. On macroscopic scale, the lower boundary is set as impermeable boundary (u_x=u_y=0), the left and right boundary is pressure boundary (left pressure p _ (in) is larger than right side pressure p _ (out) on microscopic scale, left, left). The non-equilibrium extrapolation scheme is used on the right boundary and smooth fracture surface, and the standard rebound scheme is used on the rough fracture surface. The cubic law of smooth slab fissure flow is verified by the corresponding calculation program. Based on the lattice Boltzmann method, the percolation characteristics of different rough fracture surface schemes are studied by using the method of segment random fracture length and crack width. The results show that the percolation characteristics of rough fracture surface depend on the fracture surface morphology to a great extent. With the increase of relative roughness, the law of fracture seepage deviates from the cubic law obviously. Therefore, considering the influence of the relative roughness of the fracture surface, according to the numerical results of different fracture rough surface schemes, the cubic law correction formula for the seepage of the rough fracture surface under laminar flow is proposed. It lays a foundation for the systematic study of hydraulic characteristics of complex rough fractures.
【作者单位】： 昆明理工大学建筑工程学院;中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室;
【基金】：国家自然科学基金资助(No.51408284.No.51508253,No.U1502231) 云南省应用基础研究计划项目(No.2016FB077)~~
【分类号】：TU45
【参考文献】
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