乘波布局高超声速飞行器纵向静稳定特性分析

高超声速滑翔飞行器稳定性设计方法的研究具有重要应用价值.乘波体构型滑翔飞行器由于没有平尾且飞行在高空、高超声速条件下,其纵向静稳定特性与常规飞机有很大不同,对此传统飞行力学并无相应设计依据.在相切锥乘波体理论基础上,本文建立了计及流向一阶导数和二阶导数的微元计算模型,结合牛顿法、活塞理论、切楔/切锥法的理论推导与CFD数值计算,研究了典型二维剖面在高超声速、宽攻角范围下的纵向静稳定特性,从理论角度证明了沿流向＂下凸＂的流线特征有利于保证纵向静稳定,而＂上凹＂形状特征不利于纵向静稳定,该结论通过二维和三维算例得到了验证.以上述分析为基础,解释了基于锥型流的乘波体难以满足纵向静稳定性的物理原因,以及俯仰配平舵面可能对纵向静稳定性带来的影响,并提出了相应解决方案.进一步分析表明该结论适用于宽马赫数和宽高度范围,且黏性作用并不改变上述规律,相关结论可作为高超声速滑翔飞行器气动设计的参考.

Longitudinal static stability analysis of hypersonic waveriders

The study of hypersonic glider design has great application value. Its longitudinal design has great difference with the airplane design. Because of its high flying altitude, hypersonic velocity and lack of horizontal tail, The traditional flight mechanics do not have specific design rule for such flight condition. Based on osculating cone waverider method, this paper has established an infinitesimal computational model for the analysis of its longitudinal stability, both the first and second derivative are taken into consideration. By combining Newtonian Theory, Piston Theory and Tangent Cone/Wedge Theory, the typical 2D profiles are used to investigate its longitudinal stability under hypersonic and wide angle of attack conditions. The result shows that the ＂convex＂ case could improve its longitudinal stability while the ＂concave＂ case has the contrary effect. This conclusion is verified by both 2D and 3D computational examples. On the basis of the theory above, the physical reason why conical derived waverider do not satisfy longitudinal static stability, and the influence of pitch trim rudder are also illustrated. Further analysis shows that this conclusion could also be applied to a broad Mach number and altitude, and the viciousity has little influence on such law. The conclusions of this paper could be used in the preliminary aerodynamic design of hypersonic vehicles.