结合局部次流循环的变几何轴对称进气道研究

针对常规定几何轴对称进气道在低马赫数工作时流量系数低、溢流阻力大的问题,提出了一种结合局部次流循环的变几何轴对称进气道,其通过平移进气道一级锥并引入局部次流循环重构前体激波系相结合的方法,保证了进气道在较宽马赫数范围内的流量捕获能力。通过仿真方法验证了这一设计概念的可行性,并与常规定几何轴对称进气道进行了性能对比。结果表明:该新概念可调轴对称进气道在低马赫数工作时具有良好的流量捕获性能,并且在整个工作范围内保持了较高的总压恢复性能。与按传统方法设计的定几何轴对称进气道相比,其流量系数和总压恢复系数在工作范围内的最大改善幅度分别达到27.45%和14.31%。此外,选择合适的非控制状态贴口马赫数对该设计概念的实现效果具有明显的影响。

Investigation of a Variable Axisymmetric Inlet withLocal Secondary Flow Recirculation

When the fix geometry axisymmetric inlet operates at a low Mach number, it will face the performance penalty of decreasing of mass flow ratio and increasing of spillage drag. In order to overcome these drawbacks, a new variable axisymmetric inlet with local secondary flow recirculation control is brought forward. The moveable first compression cone and forebody secondary flow recirculation method are used to control the cone shock system to make sure the high capture ability of the inlet in a wide operating Mach range. The feasibility of the variable axisymmetric inlet is verified by the computational method and compared with the traditional fixed geometry inlet. The results indicate that the new variable axisymmetric inlet has excellent mass flow captured ability at low Mach numbers and keeps high total pressure recovery in the whole operating Mach number. As compared with the traditional fixed geometry axisymmetric inlet, the maximum improvement of mass flow ratio and total pressure recovery is 27.45% and 14.31%, respectively. In addition, an appropriate uncontrolled shock on lip Mach number plays an important role on the control effect.