高超声速流中局部构件上质量引射的热防护特性研究

通过数值求解N-S方程，研究了局部构件上质量引射对表面热行为的影响及其机理，参数包括引射速度、引射区域大小、引射方向和引射位置。研究表明，质量引射可有效地降低表面热流峰值和热流分布，其原因：一是改变了局部分离流动特性；二是改变了当地的附面层结构，而附面层特性的改变是主要的影响。引射效果与引射速度关系密切，引射方向对结果影响不大，引射效率最高区域为无引射再附点后的高温高压区，在该处引射质量可有效地减缓高速外流对构件的冲击。

STUDY OF HEATING PROTECTION FEATURES BY MASS INJECTION OVER THE LOCAL STRUCTURE IN A HYPERSONIC FLOW

By solving N S equations, the effect on the heating of mass injection over the surface of a local structure and its mechanism are studied. The factors include the injection velocity, region, direction, and location. The results show that the surface heating rate and its peak can be dramatically reduced by the mass injection. The main reason is that the injection changes the local separation characteristics and boundary layer structures. The effect of injection is greatly related with the injection velocity, but less with the injection direction. The best injection location is the high temperature and high pressure region after the reattachement point; injecting in this region can effectively release the impact on the structure of the high speed external flow.