Abstract: The sub-critical oscillation characteristics of supersonic chin inlet has been investigated experimentally focusing on oscillation frequency，pressure fluctuation amplitude and oscillation type at Ma∞=2.5，3.5，4.0 with different attack angles and different throttling. The results show that，with the block ratio increasing，the shock wave oscillation amplitude values argument，and the oscillation frequency speeds up. The pressure peak value tends to sharp and pressure trough tends to deactivation. The oscillation may be divided into three types in accordance to the pressure amplitude value，named little amplitude value pressure oscillation，middle amplitude value pressure oscillation and great amplitude value pressure oscillation. The evolution process presents diversity with the block ratio of inlet exit increasing.

Key words: Ramjet engine；Inlet；Oscillation；Wind tunnel test

摘要： 为了研究超声速颌下进气道的亚临界振荡特性，利用风洞试验，进行了来流马赫数Ma∞=2.5，3.5，4.0，不同攻角，不同节流状态的试验，获得了各状态下超声速颌下进气道的亚临界振荡的频率和压力幅值。研究结果表明，超声速颌下进气道压力振荡随着堵塞度的增加，振荡幅值增大，振荡频率加快；同时振荡的压力峰值趋于尖锐、压力谷值趋于钝化。超声速颌下进气道的亚临界振荡按照压力幅值可以分为三类，即小幅值压力振荡、中幅值压力振荡、大幅值压力振荡；随着进气道出口堵塞度的增加喘振演变过程呈现多样性。

关键词: 冲压发动机；进气道；振荡；风洞试验