超声速双侧二元进气道在侧滑状态下的再起动特性数值研究

针对冲压发动机燃烧室压强过高导致进气道不起动的问题，对一种双侧布局的超声速混压式二元进气道的再起动特性开展数值研究，获得了小侧滑角下迎、背风侧进气道的再起动特性。结果表明:对于双侧布局的进气道，其再起动出现了明显的回路迟滞现象，且在小侧滑角下，迎、背风侧进气道的再起动流态出现了明显的不对称性，在不起动及再起动的过程中会出现单侧进气道不起动的现象。比较发现:迎风侧进气道较背风侧进气道更容易出现不起动，且其实现再起动更为困难。通过对比不同背压峰值作用下的进气道再起动特性发现，当进气道背压峰值大于进气道不起动背压时，进气道的再起动背压值不随着背压峰值的增大发生变化，但进气道会发生倒流，形成反向冲量，导致内阻急剧上升，发动机工作性能恶化。 

Numerical investigation on restart characteristics of two-dimensional twin-duct supersonic inlet at sideslip state

An unstarted problem of the inlet would be caused by a high combustor's pressure of the ramjet.In order to study the restart characteristics of the inlet at a small sideslip angle,an investigation on a two-dimensional,twin-duct mixed compression supersonic inlet was conducted with a numerical method.Obvious hysteresis and asymmetry was found between the inlets' flow pattern in the restarted duration.Results indicate that,the windward side inlet is easier to unstart and more difficult to restart than the leeward side inlet.Moreover,by comparing the restart characteristics of the inlet at different backpressures,it is noted that when the backpressure is higher than the inlet's unstarted backpressure,the inlet is restarted at the same point even if the backpressure peak changes.However,there is reversed flow in the inlet when the backpressure is too much high,and a large reversed impulse is generated.The interior drag of the inlet rises abruptly,leading to deterioration of the engine performance.