干雨新, 赵宁. 预处理方法在混合笛卡尔网格中的应用研究[J]. 空气动力学学报, 2018, 36(4): 651-657. DOI: 10.7638/kqdlxxb-2016.0103
引用本文: 干雨新, 赵宁. 预处理方法在混合笛卡尔网格中的应用研究[J]. 空气动力学学报, 2018, 36(4): 651-657. DOI: 10.7638/kqdlxxb-2016.0103
GAN Yuxin, ZHAO Ning. Study of precondition method in hybrid Cartesian grid and its applications[J]. ACTA AERODYNAMICA SINICA, 2018, 36(4): 651-657. DOI: 10.7638/kqdlxxb-2016.0103
Citation: GAN Yuxin, ZHAO Ning. Study of precondition method in hybrid Cartesian grid and its applications[J]. ACTA AERODYNAMICA SINICA, 2018, 36(4): 651-657. DOI: 10.7638/kqdlxxb-2016.0103

预处理方法在混合笛卡尔网格中的应用研究

Study of precondition method in hybrid Cartesian grid and its applications

  • 摘要: 使用基于混合笛卡尔网格的预处理方法,对低马赫数下的定常/非定常流动问题进行了数值模拟研究。网格生成中,在物面附近生成贴体结构网格,其余计算区域使用笛卡尔网格进行填充,两套网格之间通过查找“贡献单元”实现流场数据间的传递。同时,使用基于密度的预处理方法,发展了一套可求解从低速(极低马赫数)到常规马赫数的N-S方程求解器,时间离散使用隐式双时间步LU-SGS格式,空间离散使用具有二阶精度的格心格式有限体积方法。非定常流动问题的数值模拟过程中,使用逆距离插值来进行新现网格单元上流场参数确定。通过对NACA0012翼型在低马赫数下的定常绕流和动态失速问题的数值模拟研究表明:使用预处理方法能够加快低马赫数下数值计算的收敛速度和提高计算的准确性,基于混合笛卡尔网格的N-S方程求解器能够模拟包含运动边界的低速不可压非定常流动问题。耦合预处理技术的混合笛卡尔网格方法给包含低速和常规马赫数的复杂运动边界问题的求解提供了新的思路。

     

    Abstract: In this paper, a precondition method based on hybrid Cartesian grid is used to simulate the steady and unsteady flow problems at low Mach number. In this method, the body-fitted structured grid is used around the body surface, and the Cartesian grid is then used in the left region. To transfer information between the two grids, the technique of searching donor cell is adopted. In addition, by using the density based precondition method, a N-S equation solver, which can solve flow problems ranging from very low Mach number to general Mach number, is developed. In this solver, the implicit dual-time stepping LU-SGS scheme is used for temporal discretization, and the cell-centered finite volume method with second-order accuracy is used for spatial discretization. To simulate unsteady flow, the flow field parameters on new presented cells are determined by using inverse distance interpolation. The numerical simulations of steady flow over a NACA0012 airfoil as well as unsteady flow with dynamic stall are performed. The generated results show that the use of precondition method at low Mach number can both accelerate the convergence of numerical calculation and improve the accuracy of solution. The developed N-S equation solver based on hybrid Cartesian grid can effectively simulate unsteady incompressible flow problems including moving boundary. Therefore, it can be inferred that to combine the precondition method with the hybrid Cartesian grid is a new way to solve the moving boundary problems with low Mach number and general Mach number.

     

/

返回文章
返回