关键词: 高超声速进气道；宽高比；启动过程；横向溢流；分离区

Abstract: On the premise of the same total contraction ratio and internal contraction ratio，the starting pro.cesses of hypersonic inlet with forward-swept sidewall of different aspect ratio are investigated. The effects of as.pect ratio on the startability of this kind of inlet is summarized，and the starting processes of different aspect ratio are compared，and the mechanism of the differences is analyzed. The results show that the aspect ratio has a re.markable effect on the starting Mach number of the inlet，and the start Mach numbers of aspect ratio 3.0，4.5 and 6.0，relatively，are 3.5，3.9 and 4.6，respectively. The common characteristic of the unstart status of different as.pect ratio configurations is that there is large-scale flow separation near the bottom wall of the internal duct. Thespillage caused by the separation spills sideways through the spillage window created by the forward-swept side.wall，which has a significant effect on the flow configuration of separation zone. In the starting process，the aspectratio influences the spanwise size of the separation so as to influence the effect of side spillage on the separation， thus the startability are affected.

Key words: Hypersonic inlet；Aspect ratio；Start process；Side spillage；Separation zone