中文摘要：

基于特征线法,并考虑变比热的影响,开展了高超声速飞行器用SERN设计。利用CFD数值模拟技术,计算得到了设计状态和沿飞行轨迹其它飞行状态下的SERN内外流场和特性。可以看到,在设计状态马赫数5时,基于特征线法得到的SERN内流场分布符合设计要求,而在其它较低的飞行马赫数下,SERN处于过膨胀状态,并且过膨胀的程度随飞行马赫数的降低而愈加严重。在马赫数2.5时,喷管膨胀面气流已发生明显分离,喷管性能急剧恶化。为了提高低马赫数条件下SERN的气动性能,分析了通过调节SERN下斜板角度从而实现其气动性能提高的方法。结果表明调节下斜板角度可以明显改善SERN非设计点的气动性能。

英文摘要：

For hypersonic vehicles,the effect of nozzle aerodynamic characteristics on vehicles per-formance is serious.Based on Characteristic methods,considering effect of variable specific heat and boundary development,the methods and program for determining contour of single expansion ramp nozzles for hypersonic vehicles were developed.With CFD numerical simulation technology,The nozzle flow field and aerodynamic characteristics were computed on design point and along flight trajectory.The results in-dicated that,at Mach 5,namely design point,the performance of designed single expansion ramp nozzles is perfect,but throughout much of the low-supersonic and mid-supersonic flight regime,the performance was poor.Flow separation was observed on the expansion ramp at Mach 2.5.To improve off-design performance of single expansion ramp nozzles,the effects of cowl angle on nozzle performance were studied.The results indi-cated that adjustments of cowl angle could improve off-design performance of single expansion ramp nozzles.