基于Euler方程的二维高速海面效应数值分析

Numerical analysis of the unsteady aerodynamics of an airfoil flying at subsonic flow over a wavy surface

以近海面飞行器的海面效应为研究背景,通过数值求解可压缩Euler方程模拟了波形壁对翼型高亚声速气动力特性的影响。计算网格布局采用了重叠网格方法,避免了翼型与波形壁之间网格生成的困难。详细分析了波形壁边界条件,给出了正确的通量计算公式。时间推进方法采用了双时间方法,子迭代过程由LU-SGS方法完成。通过数值分析,给出了飞行高度、波长和波幅等因素对翼型气动力特性的影响。

The aerodynamic characteristics of an airfoil flying over a wavy surface is obviously far from that of the same airfoil flying over a flat surface. In order to investigate the unsteady aerodynamics of an airfoil flying over a wavy surface, a second order finite volume Euler code was developed. A fully implicit method （dual-time stepping method） was used, in which the Newton-like sub-iterations using LU-SGS scheme was included. To facilitate the grid generation, overset grids was chosen. It was emphasized that the reasonable wavy surface boundary condition was given in detail. In this research, the wavy surface was represented by a still sine curve. The influence of elevation, wave length and wave amplitude on the subsonic aerodynamics of an airfoil was analyzed.