激波控制矢量喷管流动与工作特性研究

利用数值模拟方法,研究了激波控制矢量喷管的流场结构与工作特性,分析了射流流量、外流马赫数及落压比对喷管流动和性能的影响。结果表明:随着射流流量的增大,射流对主流产生的阻碍作用增大,使得注气缝上游的高压分离区增大,上、下壁面压差增大,矢量角增大;但射流流量过大时,激波会影响下壁面的压力分布,使喷管推力矢量性能降低。外流马赫数增加使喷管出口附近及上壁面注气缝下游壁面的压力降低,因此上、下壁面的压差减小,喷管的推力矢量性能降低。随着落压比的增大,注气缝上游的分离激波位置后移,注气缝下游分离区内的相对压力降低,使上、下壁面的压差减小;另外,喷管工作状态从过膨胀状态向欠膨胀状态转变时,压差产生的推力增大,喷管的推力矢量性能降低。

Research on Structure and Performance of Shock Wave Control Vector Nozzle Flow Field

The flow field and the operating characteristics of a shock wave control vectoring nozzle have been investigated with a numerical simulation method.The influence of flow,external flow Mach number and pressure ratio on nozzle has been studied.The results show that with the increase of the secondary flow,it has more interference on the mainstream,making the upstream of gas injection port with a higher pressure,the differential pressure between upper and lower surface raise,and thrust vector angle increases.If the secondary flow was too big,it would have an impact on the lower surface and reduce the performance.With the increase of Mach number,the pressure of nozzle exit was reduced,so did the pressure of upper surface.The pressure between upper and lower surface decreased,thus reducing the performance of thrust vector nozzle.As the NPR increased,the separation shock in front of gas injection port moved backward,making the downstream separation of gas injection port with a lower relative pressure,so the pressure between upper and lower surface decreased,and the performance of thrust vector nozzle decreased.On the other side,the work state of nozzle changed from higher expansion to lower expansion of the state,so the thrust changed with pressure increased,and the performance of thrust vector nozzle decreased.