锯齿矢量喷管气动和红外辐射特性研究

Research on aerodynamic and infrared signature of vectoring nozzle with chevron

通过数值计算研究,分析了单锯齿喷管出口对涡扇发动机排气系统球面收敛二元喷管气动及红外辐射特性的影响。在本文的研究参数范围内,研究结果表明:与基准喷管相比,锯齿的使用均会引起推力系数下降,同时90°齿顶角锯齿会引起更大推力系数降低;锯齿喷管出口尾迹与基准喷管相比,速度核心区扩大引起速度衰减更为迅速。锯齿对主要水平方向喷管中心向两侧15°方向内尾迹红外辐射强度产生影响。无偏转的锯齿喷管在水平方向上总体红外辐射与基准喷管强度接近,锯齿作用体现在喷管偏转时。20°矢量偏转时,水平方向90°探测角位置60°顶角锯齿喷管下降95%,90°和120°顶角则分别降低25.6%和12.3%。

The influence of outlet with single-chevron on the aerodynamic and infrared performances of a spherical convergent two-dimensional nozzle used in turbofan engine exhaust system is analyzed by numerical calculation.Within the range of parameters presented in this study,the results show that:the use of single-chevron results in a reduction in thrust coefficients compared to the reference nozzle,and the 90°angle single-chevron will cause a greater thrust coefficient reduction.Compared with the reference nozzle,the speed attenuation caused by the expansion of the velocity core area of the single-chevron nozzle exit wake is more rapid.Single-chevron affects the infrared radiation intensity of the wake in the direction 15°from the center of the nozzle to both sides of the main horizontal direction.The overall infrared radiation of the non-deflection single-chevron nozzle in the horizontal direction is close to the intensity of the reference nozzle,and the single-chevron effect is reflected when the nozzle is deflected.At 20°vector deflection,the horizontal 90°detection angle position of the 60°top angle saw-tooth nozzle decreases by 95%,and the 90°and 120°angles decrease by 25.6%and 12.3%,respectively.