(修，2撤3)关键几何参数对超声速膨胀器流场和性能影响的数值研究

为了揭示关键几何参数对超声速膨胀器流动特性影响的规律，对3种隔板安装角和5种出进口面积比超声速膨胀器设计工况下的流场进行了数值研究。结果表明：随隔板安装角增加，斜激波向出口迁移，斜激波强度略有降低，超声速膨胀器膨胀比减小，效率提高；随出进口面积比增加，流道内高速区显著扩大并逐渐靠近压力面，斜激波增强，出口流动损失增加，超声速膨胀器膨胀比增大，效率降低。为获得综合性能较优超声速膨胀器结构，需在较小出进口面积比和较大隔板安装角之间做折衷选择。

Influence of the key geometric parameters on flow field and performance of a supersonic expander

To reveal the raw of the key geometric parameters effect on the flow characteristics of a supersonic expander, flow field of the supersonic expander with three kinds of strake stagger angle and five kinds of the ratio of the outlet to inlet area has been simulated numerically under design condition in this paper. The results show that with the increasing of the strake stagger angle, oblique shock waves migrates toward the outlet, intensity of the oblique shock waves is slightly reduced, expansion ratio of the supersonic expander decreases, and the efficiency increases. With the increasing of the ratio of the outlet to inlet area, high-speed zone in the channel expands significantly and gradually closes to the pressure surface, the oblique shock waves enhances, thus increasing the flow losses of the outlet, expansion ratio of the supersonic expander increases, and the efficiency decreases. In order to optimize the overall performance of a supersonic expander structure, reasonable compromises should be made between smaller ratio of the outlet to inlet area and larger strake stagger angle.