高超声速冲压发动机-飞行器计力体系讨论

Discussion on Force-Accounting System for Airbreathing Hypersonic Vehicle

关键词:  高超声速  冲压发动机  飞行器  一体化受力分析  计力体系

Key words:  Hypersonic  Ramjet  Vehicle  Force analysis  Force accounting system

摘要:

从吸气式高超声速飞行器受力分析出发,讨论如何统计飞行器受力的问题,建议在研究中使用增量法。这种方法将冲压发动机冷、热工况产生的力(力矩)增量视为飞行器运动分析中所需的“发动机推力或拉力”,这个力或力矩分别叠加在飞行器冷通气状态的力或力矩上。这样,就与传统的飞行器运动方程中的力建立了一一对应的关系,可最大限度地使用以往建立的数据获取方法、分析软件、实验技术体系,将给后续工作带来极大的便利。另外,使用此方法,实验容易获得高质量的数据,通过大量容易组织的冷态实验也可使数值模拟的准确度大大提高,使未来飞行器的运动分析结果更可信。在这个体系下,内流道的冷工况阻力(轴向力)是高超声速冲压发动机与飞行器一体化需考虑的重要问题,一方面飞行器总体任务设计需限定内流道冷阻范围,另一方面要使发动机在要求的冷阻范围内高效工作,后者是高超声速发动机研究面临的严峻挑战。 

Abstract:

In the frame of this methodology, the engine pull is figured to be the force difference when the engine (Scramjet) on (with combustion) and off (without fuel). The force or moment increments produced by these differences should be added to the vehicle aerodynamic forces or moments. The aerodynamic forces are defined with the internal flowpass ventilated and no fuel injected. It is convenient in the vehicle movement analysis using a mature methodology and test technologies established in the plane design research (for reference). Under the system the needed data can be experimentally obtained.CFD results can also be improved through mass ‘cold’ tests or corrected researches concerning some influence factors (such as test gas components). The ‘cold drag’ of the internal flowpass becomes an important factor for the vehicle configuration design. A restriction should be given for the ‘internal flowpass cold drag’ from the vehicle. And the engine will be in face of a challenge as how to work well within this restriction. 