高超声速混合模块冲压发动机亚燃模块进气道的高焓风洞试验研究

 对适用于轴对称混合模块发动机的亚燃模块进气道(工作马赫数范围3～6)进行了马赫6级高焓风洞试验研究，获得了进气道在不同反压下的性能参数及沿程静压分布。实验数据显示，进气道的流量系数在0.98以上，喉道截面的总压恢复系数为0.52,平均马赫数为2.68，临界状态附近进气道出口平均马赫数低达0.432，对应的总压恢复系数为0.171,反压为自由流静压的267.56倍，为亚燃室的高效、稳定燃烧及亚/超燃室的匹配工作创造了良好的条件。当进气道处于超声速通流状态时，内通道上、下壁面静压沿流向大幅波动且波峰/波谷互相交错，通道的弯曲使得上壁面静压整体比下壁面要高。与等截面管道的反压特性不同，该进气道三维弯曲扩张管道出口的平均马赫数随着反压的增加单调下降，总压恢复系数则随反压的增加先下降后缓慢增加，直至进气道喘振。另外，研究中来流总压由3.0 MPa变化到5.5 MPa，进气道的性能参数及内部流态无明显变化。

Wind Tunnel Tests of Hypersonic Inlets for Ramjet Modules of Ramjet-scramjet Combined Engine

The preliminary test study is conducted on hypersonic inlets for ramjet module of the ramjet-scramjet combined engine at a Mach number of 6 in a high enthalpy tunnel.The performance and static pressure distributions of the inlet under different back-pressure conditions are obtained.Results indicate:(1)The mass flow ratio of the inlet is greater than 0.98 at a Mach number of 6,at the throat section the total pressure recovery coefficient and the average Mach number are 0.52 and 2.68 respectively.When the back pressure increases to the critical value which is about 267.56 times of the free stream pressure,the total pressure coefficient reaches 0.171 and the average Mach number is lowered to 0.432 at the inlet's exit,which contributes greatly to the efficiency and stability of the ramjet combustion and the cooperation of the ramjet and scramjet.(2)When the mixing duct's exit is fully open,the static pressure fluctuates greatly along the top surface and bottom surface and the value of the former is always higher due to the curved duct.Different from ducts with constant cross section area,the average Mach number at the inlet's exit decreases monotonously and the total pressure recovery coefficient decreases to the minimum and then increases slowly until buzz occurs.In addition,when total pressure of the coming flow increases from 3.0 MPa to 5.5 MPa,there is no obvious change in either the flow pattern or the performance of the inlet.