变相位差双层波纹隔热屏冷却效率及流阻特性

In order to solve the problem of large amount of cold air and local low cooling effectiveness area caused by the characteristic of corrugated structure in the longitudinal corrugated heat shield of an afterburner，a double-layer corrugated heat shield cooling structure was proposed. The cooling effectiveness and flow resistance characteristics of the double-layer corrugated heat shield with varying phase difference and amplitude ratio were studied by numerical simulation. The results showed that when the phase difference was from -π/4 to π/4，the local low cooling effectiveness area was improved，and the surface average overall cooling effectiveness and the temperature uniformity of the heat shield were improved at the same time. The relative surface average overall cooling effectiveness and cooling effectiveness uniformity of the double-layer corrugated heat shield with phase difference π/8 were the highest，i.e. 10.49% and 13.44%，respectively. When the phase difference was too large in the positive and negative directions， it may lead to the unreasonable flow rate distribution of the film holes and could increase the shrinkage loss of the film holes entrance. In addition， it was found that the increase of amplitude ratio can effectively improve the cooling effectiveness near the peak of wave and reduce the cooling effectiveness difference between the peak and the valley of the longitudinal corrugated effusion plate. When the amplitude ratio was 2，the cooling effect was the best.