单缝流体推力矢量喷管的气动特性

流体矢量喷管重量轻,便于维修,应用前景可观。但二次流的存在造成了流场振荡,因此研究矢量喷管的流动特性具有重要的理论和工程意义。运用数值模拟方法,通过在二元收扩(2DCD)喷管的扩张段引入二次流,研究激波控制的流体推力矢量喷管的气动特性。利用分离涡模拟(DES)湍流模型进行矢量喷管非定常流场的数值计算,先后得到了流场的流线、涡量系数、密度梯度和熵的分布。结果表明:随着流动的发展,激波不断发生振荡,上、下壁面唇口处生成的涡沿着剪切层外侧不断向下游脱落;尾流内上剪切层的摆动角度和熵增皆大于下剪切层。

Study on Aerodynamic Characteristics of One-slot Fluid Thrust Vectoring Nozzle

The fluid thrust vectoring nozzle is light, easy to maintain, and has a good future in application. The existence of secondary flow causes the oscillation of the flow field, so it is valuable to study the flow characteristics in theory and engineering. By introducing secondary flow into the divergent section of two-dimensional convergent-divergent (2DCD) nozzle, the aerodynamic characteristics of fluid thrust vectoring nozzle controlled by shock wave vector are studied by numerical simulation. The unsteady flow field of vectoring nozzle is was numerically calculated by using the detached eddy simulation (DES) turbulence model in this paper. The distribution of streamlines, vorticity coefficient, density gradient and entropy of the flow field wereare obtained successively. The results show that the shock wave oscillates continuously with the development of the flow. The vortices generated at the lip of the upper and lower walls shed downstream continuously along the outer side of the shear layers. The oscillation angle and entropy increase of the upper shear layer in the wake are larger than that of the lower shear layer.