一种基于引射效应的流体推力矢量新技术

 流体推力矢量是一种利用流动控制技术实现推力转向的方法,针对现有二次流动控制推力矢量方案的不足,提出了采用引射方式的新型流体推力矢量技术,该技术在喷管套管内利用引射作用产生低压区使主流方向偏转,实现推力转向。并且可以通过限制流量的方法调节主喷流对单侧套管的抽吸程度,使得在喷管套管内产生不同的横向压力梯度,达到了矢量化控制推力转向的目的。运用这一概念设计了矩形矢量喷管,采用数值模拟方法验证了喷管的推力转向效果,探讨了该矢量喷管内喷流转向形成的流动机理,从推力损失、转向效率上对喷管的性能特点进行了分析。计算结果表明:该矢量喷管的最大推力转向角度达到24°,对应喷流附壁状态,在喷流附壁之前可以矢量控制的推力转向角为0°~13°,推力损失在1.5%~7.0%之间变化。最后根据该计算外形以1∶10比例加工了矢量喷管,运用高压气源进行了尾喷流偏转试验。试验表明该矢量喷管在设计状态能够实现射流矢量偏转,从原理上验证了该推力矢量方案的可行性。

A New Fluidic Thrust Vectoring Technique Based on Ejecting Mixing Effects

Fluidic thrust vectoring is a technology aiming at deflecting exhaust nozzle jets by flow control. To overcome the shortcomings of existing fluidic thrust vectoring techniques which use secondary flows, a new exhaust nozzle is proposed which produces pressure gradients within the collar by ejecting mixing effects, forces the nozzle jets to deflect and produce thrust vectoring. The pressure on one collar can be conditioned by mass flux limitation while on the other remains unvaried; thus different pressure gradients are formed, and thrust vectoring is achieved. Based on this, a rectangular exhaust nozzle is designed, and numerical simulation is performed to investigate the flow mechanism and compute the aerodynamic characteristics such as vectoring efficiency, thrust loss, etc. Results show that the maximum vectoring angle of the nozzle is 24°, which corresponds to jet attachment on one collar, while the controllable vectoring angles are in the range of 0° to 13°, and the thrust losses vary between 1.5% and 7.0% depending on jet vectoring angles. According to the computation, a 1∶10 sub-scale model is made and exhaust nozzle experiments are conducted using a high pressure gas tank. In the experiments jet vectoring are achieved under the design conditions, which testifies in principle the feasibility of the thrust vectoring scheme.