利用火焰面模型和混合LES/RANS方法对某支板构型超燃冲压发动机进行模拟,讨论了化学反应对湍流流场的影响,并比较了3D和2D模拟的差别.结果表明,不考虑化学反应时剪切层中的大尺度结构控制着整个混合过程,且剪切层具有明显的三维特性;2D模拟能捕捉到涡的配对与合并现象,而3D模拟中涡的拉伸、扭曲及破碎特性更加显著;考虑化学反应时,由于燃烧释热的影响,支板尾部回流区变大,射流穿透度减小,大涡结构产生和饱和的位置有所推迟;数值阴影与实验阴影符合,时均速度剖面、温度剖面与实验值一致,3D模拟在预报准确性方面明显优于2D模拟.%Flamelet model and hybrid LES/RANS method were used to simulate SCRAMJET with strut for the Chenmiceal Propulsion of theGerman Aerospaee Center (DLR). The effect of reaction on turbulence was discussed, and comparison between 2D and 3D simulation were presented. The results show the following indication: (1) Mixing is controlled by large eddy scales in nonreacting flow,and the shear layer has three effects obviously; In addition, the combination and pairing of large eddy scales can be seen in 2D simulation, while stretching, distorting and breaking up can be seen in 3D simulation; (2) In reacting case, jet penetration decreases and recirculation zone becomes larger, while, owing to heat release, large eddy scales turn up and saturation appears late. (3)Numerical shadow picture displays good agreement with experimental shadow photograph, while velocity and temperature measurements are consistent with experimental data qualitatively and quantitatively, but 3D model is superior to 2D model in result accuracy.
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