亚声速条件下外形参数对逆流矢量喷管性能影响的模拟研究

Effects of Geometric Parameters on Performance of Counter-Flow Vectoring Nozzle in Subsonic Conditions

为逆流矢量喷管几何构型选取提供理论依据,采用数值模拟方法研究了零攻角亚音速条件下抽吸角、横向高度及垂直段高度等外套管外形参数对逆流推力矢量喷管内部流动结构及矢量性能的影响,得到了推力矢量角、合成推力系数、二次流流量比等随外形参数的变化规律。研究结果表明:抽吸角及外套管垂直段高度对逆流矢量喷管的推力矢量角变化均无大的影响,且抽吸角及外套管垂直段高度分别变化时,两者的最大矢量角和最小矢量角的角度差均不超过0.35°,合成推力系数均随两者增大而减小,抽吸角变化时合成推力系数在0.778左右,其变化值不超过0.001,垂直段高度变化时合成推力系数范围为0.77~0.84,而流量比受抽吸角及垂直段高度变化的影响均微小;横向高度较小时,主流易发生附体,随其增大,推力矢量角增加,最大值达7°,而合成推力系数随之减小,范围为0.75~0.87,抽吸二次流流向由同向转变为逆向,流量增大,最大流量比为2%;推力矢量喷管的整体性能较无外流时明显下降。

To provide a theoretical basis for the selection of counter-flow thrust vectoring nozzle geometry,numerical simulation method was applied to study the internal flow structure and performance of the counter-flow thrust vectoring nozzle with suction angle,suction collar horizontal height and vertical height in zero attack angle and subsonic conditions. The changes of thrust vector angle,resultant thrust ratio,and secondary mass flow ratio were obtained. Research results indicate that both suction angle and collar vertical height have less effects on the change of the counter-flow vectored nozzle thrust vector angle. And when suction angle and collar vertical height changes respectively,the angular deviation between their maximum and minimum vector angle is not more than 0. 35°. Resultant thrust ratio decreases with the increasing of suction angle and collar vertical height. When suction angle changes,resultant thrust ratio is about 0. 778 and the change value is not more than 0. 001. Resultant thrust ratio is in the range from 0. 77 to 0. 84 as vertical height changes. Mass flow ratio is less affected by suction angle and collar vertical height. Jet attachment easily occurs when horizontal height is too small. With increasing of horizontal height,thrust vector angle increases,and it can achieve the maximum value 7°. On the contrary,resultant thrust ratio decreases and it is in the range of 0. 75 ~ 0. 87. During the procedure of increasing horizontal height,suction flow shifts up to 2% from co-flow to counter-flow and mass flow ratio increases. The overall performance of thrust vectoring nozzle significantly decreases compared with no outflow.