单边膨胀喷管几何参数对性能的影响研究

Effects of Geometric Parameters on Performance of Single Expansion Ramp Nozzles

在实验数据验证的基础上,通过三维数值计算的方法,研究了单边膨胀喷管几何参数对其内特性的影响,给出了各模型在不同落压比下的性能参数。计算结果表明:下腹板角度越大,流量系数越小,下腹板向上倾斜模型的流量系数比向下倾斜的模型低了约2%;在低落压比下,上膨胀面长度越短,轴向推力系数越低,其中上膨胀面最短的模型轴向推力系数约为85%;喉道宽高比越大,流量系数越大,喉道宽高比不同,轴向推力系数差别也较大;尾缘有切角,会使喷管后气体更充分地膨胀,下腹板有切角的模型,其推力矢量角较小,其中,下腹板切角较小的模型最大推力矢量角约为12°。

Based on 3-D numerical calculations, validated by experiment data, the effects of geometric parameters on the internal performance of single expansion ramp nozzles（SERNs） were studied,revealing the performance parameters of models at different nozzle pressure ratio. The results show that as flap angle increases,discharge coefficient Cm decreases,and Cm of the upward angle is about 2% lower than that of the downward.On the condition of low nozzle pressure ratio（NPR）,axial thrust ratio Cfx of the short ramp is smaller than that of the long ramp,including that Cfx of the shortest is about 85%. The larger throat aspect ratio obtains larger Cm,while Cfx varies with throat aspect ratio. Serrated trailing edge angle makes plume expanding better,and the flap serrated angle gets small resultant pitch thrust-vector angle δp,such as the small flap serrated angle,of whichδpis 12°.