An overset-grid method for 3D unsteady incompressible flows
An overset-grid method for 3D unsteady incompressible flows
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DOI：
10.1016/s0021-9991(03)00331-0
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发表时间：
2003-11
影响因子：
4.1
通讯作者：
Han-song Tang;S. C. Jones;F. Sotiropoulos
中科院分区：
文献类型：
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作者：
Han-song Tang;S. C. Jones;F. Sotiropoulos
提出了一种复合网格数值方法，用于模拟复杂几何形状的非定常三维不可压缩流动。采用基于双时间步人工压缩法的二阶精确有限体积方法求解控制方程。采用重叠网格对任意复杂几何图形进行离散化，并提出了一种新的接口算法，以方便相邻网格之间的通信。该算法受复合区域满足全局质量守恒的充分必要条件的启发，在三维环境中实现简单。数值实验结果表明，该插值方法使重叠区域的非物理杂散振荡最小化，对网格细化的敏感性降低，大大提高了迭代算法的计算效率，优于直接的全流变量三线性插值。当用不同的空间分辨率离散相邻的重叠子域时，新方法的优点尤为明显。通过将该方法应用于计算安装在两个端板之间的圆柱体的涡流脱落和具有两个壁挂障碍物的矩形通道中的流动，证明了该方法作为模拟复杂工程流动的强大技术的潜力。
A composite-grid numerical method is developed for simulating unsteady, three-dimensional (3D), incompressible flows in complex geometries. The governing equations are solved using a second-order accurate, finite-volume method based on the dual time-stepping artificial compressibility approach. Overset grids are employed to discretize arbitrarily complex geometries, and a new interface algorithm is developed to facilitate communication between neighboring grids. The algorithm is inspired by the necessary and sufficient conditions for satisfying global mass conservation in a composite domain and is simple to implement in 3D. Numerical experiments show that the new interpolation scheme is superior to straightforward, trilinear interpolation of all flow variables as it minimizes non-physical spurious oscillations in the overlap region, is less sensitive to grid refinement, and greatly enhances the computational efficiency of the iterative algorithm. The advantages of the new method are especially pronounced when adjacent overset subdomains are discretized with different spatial resolutions. The potential of the method as a powerful technique for simulating complex engineering flows is demonstrated by applying it to calculate vortex shedding from a circular cylinder mounted between two endplates and flow in a rectangular channel with two wall-mounted obstacles.