超燃冲压发动机尾喷管进口气流角畸变研究

Effects of Inlet Flow Angle Distortion on Scramjet Nozzle

关键词:  超燃冲压发动机  单边膨胀喷管  气流角畸变  马赫数畸变  数值模拟  气动性能

Key words:  Scramjet  Single expansion ramp nozzle  Flow angle distortion  Mach number distortion  Numerical simulation  Aerodynamic performance

摘要:

为探索气流角畸变对超燃冲压发动机尾喷管性能的影响，开展了喷管在单一气流角畸变和耦合畸变进口条件下的数值模拟研究。首先简要介绍采用的数值模拟方法，并根据实验结果校核数值方法的有效性。同时为得到准确的数值结果，进行了网格无关性验证。然后，通过数值模拟获取超燃冲压发动机燃烧室出口气流参数，用于研究气流角畸变对喷管性能的影响并讨论了其影响规律。在此基础上，进一步研究了气流角畸变与马赫数畸变相互耦合对喷管气动性能的影响。结果表明，气流角畸变对推力影响很小：推力系数变化仅为0.37%；但对升力和俯仰力矩影响显著，相应增幅分别可达51.84%和12.11%。此外发现气流角畸变和马赫数畸变对喷管气动性能的影响是相互独立的。因此在超燃冲压发动机喷管的相关研究过程中，有必要对气流角畸变加以考虑。另外还需要关注由于气流角畸变导致的喷管升力和俯仰力矩变化对飞行器整体稳定性的影响。

Abstract:

In order to explore the effects of the flow angle distortion on the aerodynamic performance of the Scramjet nozzle， the numerical simulation study of the nozzle under single flow angle distortion and coupled distortion inlet conditions was conducted. Firstly， the numerical simulation method applied in this study was introduced briefly； the accuracy of which was validated by the experiment and the grid resolution study was also conducted for obtaining an accurate numerical results. Secondly， the flow condition on the outlet of the Scramjet combustor was used to study the actual flow angle distortion on the aerodynamic performance of Scramjet nozzle . On this basis， the influence of the coupling between the flow angle distortion and the Mach number distortion on the aerodynamic performance of nozzle was further studied. From the numerical results， the influence of flow angle distortion on the thrust is still small， and the increment of thrust coefficient is only 0.37%. The lift still increases significantly by 51.84%， and the pitching moment increases by 12.11%. Further， it is found that the effects of flow angle distortion and Mach number distortion on the aerodynamic performance of nozzle are independent. Therefore， it is necessary to consider the influence of flow angle distortion in the design of the Scramjet nozzle. In addition， the variation of the lift and pitching moment by flow angle distortion should be paid attention since the lift affects the trim of the hypersonic vehicle.