关键词: 超音速进气道;非均匀流;激波-边界层干扰

Abstract: An experimental Study of a two dimensional inlet model in non-uniform supersonic flow are presented.The experiment were carried out at a nominel Mach number of 2.25 and 2.50 in the DLR’s small supersonic wind tunnel (KUG).The turbulent boundary layer in the top wall of the test Section was fully or partly swallowed by the test inlet model. In this way the influence of incoming flow non-uniformity on inlet performance was investigated. The results indicated that the ramp shock-boundary layer interaction was significantly affected by the behaviour of the boundary layer bleed gap and the flow non-uniformity in the entrance of the inlet model. With the increase of the boundary layer beed gap height, the shock-boundary layer interaction length L was increased at first, then droped rapidlywhen all of the boundary layer was bypassed through the bleed gap.In comparison with the baseline inlet which was operated at the condition of M = 2.25 uniform stream,the inlet stagnation pressure recovery factor & and inlet mass flow rates were reduced nearly 18% and 15% respectively when all of the incoming boundary layer was swallowed by the Inlet. At the same time> the stagnation pressure distortion D and the RMS deflection of the Mach number contour in the inlet measuring station were increased by live to seven times in comparison with that of the baseline inlet. It should be emphasized that the flow patterns in the boundary layer bleed gap had a non-negligible effect on the behaviour of the ramp shock-boundary layer intetract-ion and on the inlet performance. In the boundary layer bleed gap there were two kinds of flow patterns that were dominated by the bleed gap height. The first pattern was subsonic flow at the gap entrance and the second was supersonic entrance flow. The significant decrease of inlet performance was mainty due to the breathing of a low energy boundary layer flow into the test inlet.

Key words: Supersonic inlet;Non-uniform flow;Shock wave boundary layer interaction