超燃冲压发动机进气道内激波/边界层干扰研究

外界存在多种因素引起隔离段反压增加，将直接影响到进气道内波系的结构和强度，进而影响到因激波诱导而分离的边界层情况．在设计状态下，建立二维的进气道模型，运用RSM湍流模型，对单个超燃冲压发动机进气道隔离段内复杂流场进行数值模拟．得到对应不同反压时，超燃冲压发动机进气道的激波与边界层相互作用情况．研究发现，反压为0时，隔离段内分离区较大，出口马赫数较低，尾部波系较弱，为燃烧室稳定燃烧提供有利条件．随着反压的增加，即使总压恢复系数有所增加，但隔离段尾部的气流稳定性降低．因此，要合理调节隔离段反压大小，以便更好地协调总压损失和尾部气流稳定性的矛盾，对于进气道工作最优化的控制起到一定的参考作用．

Interaction of shock/boundary layers in a scramjet inlet

Increasing back pressure due to external factors has great impact on the structure and intensity of shock waves,and so affects the induced separation of boundary layers.A 2-D model of a scramjet inlet was developed,simulating the complex flow field of the isolating section in one of the inlets using the RSM turbulence model.The interaction of shock waves and boundary layers of the inlet under different back pressures was calculated.The results show that the separation zone inside the isolating section is larger and the Mach number in the outlet is lower when the back pressure is 0.At this level,shock waves are relatively weak,thereby providing favorable conditions for stable burning in the combustion chamber.With increasing back pressure,the total pressure recovery coefficient increases a bit,but the air flow stability decreases in the tail zone of the isolator.Therefore,it is necessary to properly adjust the back pressure of the isolator of a scramjet engine in order to resolve the contradiction between total pressure loss and stability of the flow field in the tail zone.This research provides a reference for optimal control over the operation of a scramjet inlet.