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.