关键词: 高超声速；进气道；启动过程；内收缩段；分离区

Abstract: On the purpose of giving insight into the motion law，factors and self-sustained mechanism of the large-scale separation zone in the inlet start process，the accelerating start process of simplified 2-dimensional hypersonic inlet were investigated. The startability，start process and motion law of separation zone of different cowl angle configurations were compared，and the flow mechanism was analyzed. The results reveal that: (1)The startability of 2-dimensional upper wall one-side compression inlet is influenced by the cowl angle significantly. With the cowl angle increasing from 0° to 12°，the start Mach number shows a trend in which it decreases first and then increases，reaching a minimum at 4°.(2)Large-scale separation zone exists in all cowl angle configurations in unstart status. The upstream half of the separation zones are nearly the same，while the downstream halves are distinctly different.(3)In the accelerating start process，the separation zones sustain itself mainly depending on the reflection shock of separation shock at the upper wall. At the same incoming flow Mach number，the strength of the reflection shock of separation shock at the upper wall of different cowl angle configurations is different，which influences the self-sustained ability of the separation zone so as to influence the startability.

Key words: Hypersonic；Inlet；Start process；Internal duct；Separation zone