抽吸对方转圆内收缩进气道性能的影响

针对马赫数可控的方转圆内收缩进气道设计了抽吸方案，并通过风洞试验和数值仿真手段研究了其对进气道性能的影响，获得了进气道设计点的工作特性及自起动性能。试验结果验证了抽吸对提升内收缩进气道性能的有效性：在顶板下洗气流集中区域开槽减小了出口涡流区以及提高了抗反压能力，相对原型进气道，设计点（Ma=6.0）放气流量为0.99%的实际捕获流量时出口总压恢复系数提高了3.8%，临界反压从135倍来流静压提高到了150倍。此外，在顶板分离区开槽可以提高进气道的自起动能力，Ma=5.0，攻角AOA=4°时实现了自起动，此时放气流量为0.78%的进口捕获流量，起动后出口增压比和总压恢复系数分别为30.6和0.600。

Effect of suction on performance of inward turning inlet with rectangular-to-circular shape transition

Various suction schemes are designed for an inward turning inlet with rectangular-to-circular shape transition with controlled Mach number distribution. Experiments and numerical simulations are conducted to analyze the influence of the scheme on the performance of the inlet. The operation characteristics of the design point and the self-starting performance are obtained. The experimental results validate that suction can efficiently improve the performance of the inlet. The bleeding in the downwash concentration region of the top wall can obviously reduce the exit vortex region and improve the back pressure resistance. Compared with those of the original inlet, the total pressure recovery coefficient increases by 3.8% and the critical back pressure increases from 135 times of the free stream static pressure to 150 times at the exit section on the design point (Ma=6.0), when the relative bleeding flux is 0.99%. In addition, the bleeding in the separation region of the top wall can promote the starting ability. When Ma=5.0 and AOA=4°, the inlet realizes self-starting with the relative bleeding flux being 0.78%. When the inlet restarts, the corresponding compression ratio and the total pressure recovery coefficient at the exit section are 30.6 and 0.600, respectively.