格林函数方法的基本原理在近代高速飞机设计中,迫切需要发展一种快速而又准确的定常及非定常气动力数值计算方法,以适应飞机结构设计、舵面及操纵系统设计以及气动弹性分析的需要。格林函数方法就是其中的一种,它的基本原理是采用格林函数方法,将以扰动速势为未知函数的偏微分方程转化为积分方程(对定常流动)或积分—微分方程(对非定常流动),然后离散化求解。这一 方法的主要特点是对亚、超音速线化流动,仅需在物体表面上划分网格,比直接求解偏微分方程计算量要小得多。对跨音速流动,虽然除了物面上的网格外,在流场中也需划分一定的网格,以计入非线性影响,但与差分法相比,其空间网格数及迭代求解次数均要少得多。本方法不仅计算量小, The basic principle of Green’s function method In modern high-speed aircraft design, there is an urgent need to develop a fast and accurate numerical method for steady and unsteady aerodynamics to adapt to the design of aircraft structures, the design of control surfaces and control systems, and the analysis of aeroelasticity need. Green’s function method is one of them. The basic principle of Green’s function method is to use Green’s function method to convert partial differential equations (for stationary flow) or integral-differential equations (for unsteady flow ), Then discretized to solve. The main feature of this method is that for sub-supersonic linear flow, meshing is only required on the surface of the object, which is much less computationally expensive than solving the PDE directly. For transonic flow, although some grids are divided in the flow field in addition to the grids on the object surface to account for the nonlinear effects, compared with the difference method, the number of spatial grids and the number of iterative solutions Much less. This method is not only a small amount of computation,