基于等熵压缩面型面坐标变换的二维曲面压缩面数值模拟

利用坐标变换矩阵对等熵压缩面型面坐标进行缩放变换，得到一系列不同曲率的二维曲面压缩面.利用数值模拟手段对该系列曲面压缩面进行了研究，并与壁面马赫数线性分布和压升规律可控的压缩面进行了比较.结果表明:等熵压缩面型面坐标变换后其长度明显缩短，在相同总偏转角下x轴坐标缩放比例因子为0.7的曲面压缩面长度缩短30%；不同x轴坐标缩放比例因子的曲面压缩面产生分散、不汇聚于一点的压缩波并能保持等熵压缩的流动特征，壁面压力分布得到一定程度的改善且随着x轴坐标缩放比例因子的减小，壁面马赫数逐渐趋于呈线性分布；x轴坐标缩放比例因子为0.5的曲面压缩面同壁面马赫数线性分布的压缩面在流场结构、壁面压力、壁面马赫数分布以及出口截面总压恢复系数、出口截面马赫数分布方面具有高度的相似性. 

Numerical simulation of two-dimensional curved compression surface with isentropic surface coordinate transformation

Different coordinate transformation matrixes were used to scale the coordinate of isentropic surface, and a series of two-dimensional curved compression surfaces with different curvature were obtained. The curved compression surfaces were studied using numerical simulation, and then compared with the curved compression surfaces with wall Mach number linear distribution and controllable law of pressure rise. The result shows that: the surface length can be shortened obviously due to coordinate transformation of isentropic surface, and the curved compression surface length scaled using x axis scaling factor of 0.7 can be reduced by 30% at the same total turning angle. The curved compression surfaces with different x axis scaling factors produce dispersed compression waves that will not be converged to one point, and the isentropic compression flow characteristics can be kept. Wall pressure distribution is improved to a certain extent and wall Mach number distribution tends to be linear with decreasing x axis scaling factor. The curved compression surfaces with x axis scaling factor of 0.5 and wall Mach number linear distribution have similarity in the flowfield structure, wall pressure, wall Mach number distribution, exit total pressure recovery coefficient and exit Mach number distribution.