基于非结构网格的Gas-Kinetic方法

Gas-Kinetic method based on unstructured meshes

为解决带有复杂几何边界条件的高速流体计算问题,提出基于非结构网格的Gas-Kinetic方法.对于二维非结构网格,以三角形网格作为计算单元,形成在该网格控制单元中物理量导数求解的新方法.通过物理量导数得到在控制体积元边界上的通量,然后用每个计算时间步中求出的边界通量和控制体积元中的物理量,求出下一计算时间步所需的新物理量,依次进行计算直到计算结果收敛为止.采用NACA0012翼型进行数值计算验证,结果表明该方法简单高效,适用于低速和高速流体的计算.

To solve the computation problem of high-speed fluid considering the condition of complicated geometrical boundary, a Gas-Kinetic method based on unstructured meshes is proposed. In the method, triangle mesh is taken as the computation element for 2D unstructured mesh, and a new method of solution on physical quantity derivatives in the mesh control elements is presented. The flux on the boundary of control volume units is obtained by physical quantity derivatives. Then the flux on boundary and the physical quantities in mesh control units, which are solved at each calculation time step, are used to solve the new physical quantities at the next calculation time step, and the calculation goes on in turn until the numerical results reach convergence. NACA0012 airfoil is used to validate the numerical computation and the results show that the method is simple and efficient. So it can be applied to the computation on low-speed and high-speed fluid.