来流马赫数对附面层的影响

本文从附面层积分方程出发, 定性地分析了当表面压力系数 C_p分布相同时, 在保证Re数相等的条件下进口 Ma数对附面层发展的影响。并且用数值方法进行了模拟。与此同时用数值方法对由于表面曲率和自由流紊流度所引起的影响作出估计。结果表明; 在表面压力系数分布和 Re相同的情形下, 进口Ma数, 直到临界值附近时, 所引起的附面层的变化量是很小的, 一般在工程允许的误差范围之内。表面曲率所引起的变化同马赫数引起的变化相近, 而进口自由流紊流度引起的变化较之前两者较为明显。 

THE INFLUENCE OF THE INLET MACH NUMBER ON THE BOUNDARY LAYER DEVELOPMENT ON TURBOMACHINERY BLADE SURFACES

When Reynolds number and the blade surface pressure coefficient distribution are kept constant,the influence of the inlet Mach number on the boundary layer development on the blade surfaces of turbomachinery is discussed with numerical simulation as well as an order of magnitude analysis,based on the integral boundary layer equation.The effects of surface curvature and the free stream turbulence intensity on the development of the boundary layer are also estimated by the numerical simulation.The results show that at the same Reynolds numbers and surface pressure coefficient distributions,the variation of the non dimensional the integral parameters boundary layer with the inlet Mach number is very small,up to the critical Mach number,the changes are usually within the engineering tolerance.The variation caused by the surface curvature difference is of the same order of that due to Mach number,however the free stream turbulence level can cause remarkable changes in the development of the boundary layer.