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

摘要： 在总收缩比和内收缩比一定的前提下，对不同宽高比的侧板前掠高超声速进气道启动过程进行了研究，总结了宽高比对这类构型进气道启动性能的影响规律，对比了不同宽高比构型启动过程的差异，分析了造成这些差异的流动机理。结果表明:宽高比对侧板前掠二维进气道的启动马赫数有显著影响，宽高比 3.0，4.5，6.0的进气道启动马赫数分别为 3.5，3.9，4.6。不同宽高比不启动状态的共同特征，是内收缩段底板附近存在大规模流动分离，分离形成的溢流主要通过前掠侧板形成溢流窗口进行横向溢流，横向溢流对分离区流场结构有重要影响。在启动过程中，宽高比通过影响不启动状态分离区的展向尺度，影响了横向溢流对分离区排移效果，从而影响了进气道的启动性能。

关键词: 高超声速进气道；宽高比；启动过程；横向溢流；分离区