并联式TBCC发动机排气系统气动特性研究

采用变比热计算方法对Ma7一级并联式TBCC发动机排气系统的内外流场进行了三维数值模拟研究,分析了其在整个飞行包线范围内的气动特性,研究结果显示:在涡轮模态过程中,当马赫数较低时,排气系统的气动特性较差,随着马赫数的增加其性能逐渐好转;在模态转换过程中,虽然排气系统的流场结构十分复杂,但是没有出现明显的流动分离现象,整个排气系统气动特性变化平稳,有利于模态转换的顺利完成;在冲压模态过程中,排气系统的流场结构均匀,推力系数虽然略有降低,但是总体保持在一个比较高的水平。

Aerodynamic Characteristics of the Over-Under TBCC ExhaustSystem

The internal and external flow field of a Ma7 over-under TBCC engine exhaust system is simulated by the method of variable specific heat, the aerodynamic characteristics of the exhaust system in the whole flight envelope are analyzed. Research results show that: in the subsonic mode, when the Maher number is low, the aerodynamic performance of the exhaust system is poor, and the performance of the system is improved with the increase of the Maher number. In the transition mode, although the flow structure of exhaust system is very complex, but there is no obvious flow separation phenomenon and the exhaust gas system dynamic properties vary smoothly, to mode transition completed successfully. In the supersonic mode, the flow field structure of the exhaust system is uniform, while the thrust coefficient is slightly reduced, but the overall level is maintained at a relatively high level.