膨胀型面造型方式对超声速膨胀器流场及性能的影响

Influence of Different Expansion Surface Shapes on the Flow Field and Performance of a Supersonic Expander

为了获得综合性能较优的膨胀器结构,对所设计3种膨胀型面的超声速膨胀器的三维流场进行了数值研究。研究结果表明:膨胀型面显著影响三维流道的局部流场和性能,沿节距方向直线型膨胀型面的膨胀器速度分布在3种膨胀型面结构中最为均匀,出口平均绝对马赫数最大,膨胀比最大,说明S2流面沿流向逐步缓慢扩张有利于气流的膨胀加速。3种膨胀型面膨胀器的膨胀比和等熵绝热效率均随进口总压和转速的上升而增加。

In order to optimize the performance of a supersonic expander, the three-dimensional flow field of the supersonic expander with three kinds of expansion surface shapes were simulated numerically. It was found that the expansion surface shape has a significant influence on the local flow field and performance of the three dimensional flow-path under design condition, the velocity distribution of linear expansion surface along the direction of pitch is especially uniform, and the averaged Mach numbers at the exit and the expansion ratio are maximum. It states that the stream surface of S2 expansion along the airflow gradually is more benificial to achieve expansion and acceleration. With the increasing of inlet total pressure and speed, expansion ratio and adiabatic efficiency of supersonic expander with three kinds of expansion surface shape increase, respectively.