基于非结构化网格有限体积的LBM

提出了一种基于非结构化网格有限体积的LBM.采用Cell-vertex有限体积法离散控制方程.该方法在时间上采用伪、实二时间步,其中伪时间步采用向前差分,实时间步采用二阶向后差分方法;空间上采用edge-based通量计算方法,采用高阶TVD格式计算控制体边界通量.离散后的控制方程采用隐式迭代,控制变量采用五层二阶Runge-Kutta方法求解.二维同心圆环内圆柱间Couette流与顶盖驱动方腔流的数值结果显示该方法为一种有效求解不规则边界流体动力特性的实用工具.

Unstructured mesh finite volume LBM

A unstructured mesh finite volume LBM is presented. Cell-vertex finite volume method is used to discretize the governing equations. During the discretization in time, there are two-time steps, pseudo-time step and real time step respectively, in which forward scheme is used in former while the second order backward scheme is used in latter. In space, an edge-based flux calculating algorithm is adopted and higher order TVD scheme is utilized to calculate the flux through control volume interface. A strategy of implicit iteration is used for solving discrete governing equations and the second order five-layer Runge-Kutta method is utilized for the solution of variables. The simulating results of 2D cylindrical-Couette flow and lid-driven cavity flow show that the proposed method is believed to be an effective tool for solving flow pattern of flow domain with irregular boundary.