关键词: 超声速进气道；形状记忆合金；涡流发生器；激波/边界层干扰

Abstract: In order to control the cowl shock/boundary layer interaction in a supersonic inlet， a set of variable microramps with large length height ratio based on the shape memory alloy is brought forward. The feasibility and control effect of the variable microramp are verified by the wind tunnel test. The results show that the microramps with large length height ratio can transform their profiles automatically driven by the shape memory alloy. The deformation value of the microramp fits the design one well. The error between the height of the microramp tail and the design one is 3% at the air flow static condition while the value is 5.4% at the wind tunnel test. Under the control of the variable microramps with large length height ratio， the large separation bubble induced by the cowl shock/boundary layer interaction is effectively controlled which is broken into series small ones in the spanwise direction. Meanwhile， the microramp-induced vortex pair strengthens the mixing effect between the low-momentum flow in the separation bubbles and the main flow. As a result， the reattachment of the separated flow is enhanced. When the inlet operates at Mach 3.8， the mass weighted average total pressure recovery on the inlet exit plane is 0.603 while the value in the uncontrolled condition is only 0.557.

Key words: Supersonic inlet；Shape memory alloy；Microramp；Shock/boundary layer interaction