喷流压比对高超声速流场调制传递函数的影响

Influence of Pressure of Jet on Hypersonic Flow Field Modulation Transfer Function

设计搭建了基于高超声速(Ma=6.0)炮风洞的气动光学地面试验平台,试验对象为带冷却喷流装置的光学头罩模型.利用高速摄像机并结合背景纹影技术获取了喷流压比为0、04、1.0、1.16和1.8五种状态下的光线偏折信息,结合几何光学传递函数理论获取了对应状态下流场的调制传递函数.试验结果表明,喷流压比增大使得流向和展向的调制传递函数包络面积减小,较大喷流压比下流向调制传递函数在2~4 lp/mm区间出现波动现象.

An aero-optical ground test platform based on the hypersonic(Ma=6.0)gun tunnel was built.The test object was an optical dome model with cooling jet structure.Combined with background oriented schlieren technology,a high-speed camera was used to obtain the light deflection information of the flow field with five different pressure of jet value:0,04,1.0,1.16 and 1.8.And the corresponding modulation transfer function was calculated with the geometric optics theory.The experimental results show that the increase of pressure ratio of jet value can reduce the envelope area of the modulation transfer function of the flow direction and span direction.The flow direction modulation transfer function fluctuates between 2~4 lp/mm under larger pressure ratio of jet value.