两种典型非结构网格变形方法特性对比研究

非定常流动仿真中常常遇到运动边界的情形,基于物理模型的线性弹簧法和基于数学方法的径向基函数(RBFs)插值法是实现计算网格随运动边界变化的两种主要的非结构网格变形方法。以NACA0012翼型的俯仰运动为例,对上述两种方法的变形特性进行较详细地定量分析研究,比较线性弹簧法和RBFs方法的CPU计算时间和最大变形能力,分析两种方法的网格质量随俯仰角度和运动步数的关系,并给出典型状态下网格单元质量云图和流场计算结果。结果表明:基于RBFs插值的网格变形方法计算效率较高,变形能力较强且能保持较高的网格质量,是一种高效的网格变形方法。

A Comparative Study on Two Typical Unstructured Grid Deformation Methods

In simulation of unsteady flow, the moved boundary should be often considered. The linear spring a nalogy method, based on the physical model, and the radial hasis functions（RBFs） interpolation method, hased on the algebraic method are two typical and common unstructured grid deformation methods to achieve the com- puting grid deformed with the moved boundary in unsteady flow simulation. A detailed quantitative study is con- ducted on the deformation characteristics of the two methods. First of all, the pitching of NACA0012 airfoil is taken as an example to compare the CPU time and the maximum deformation capacity ot＂ the two methods. Fur- thermore, the mesh quality and cell quality contours under typical pitch angles change with pitching angles and time steps are also studied. A standard flow solver result is proposed as well. The above results show that the RBFs method is remarked with higher numerical efficiency, stronger adapting ability for large mesh deformation and higher stability for mesh quality comparing with the linear spring analogy method.