论文部分内容阅读
受到风洞实验能力的限制,高速飞行器气动光学效应实验很难与其实际飞行情况完全一致。雷诺数作为重要的相似准则数,在经典流体力学风洞实验中应用广泛,研究其对于气动光学效应的影响,对于建立气动光学相似准则具有重要意义。基于∏定理对可能影响气动光学效应的变量进行分析,证明了雷诺数是影响气动光学效应的一个相似准则数;通过创新性设计变雷诺数实验装置,可以实现喷流单位雷诺数在106~108 m-1范围内变化。通过选取八个典型的雷诺数,并利用BOS-WS(BOSbased Wavefront Sensor)技术测量了对应状态的光程差,通过函数拟合的方法得到了光程差的均方根值与雷诺数之间的幂函数关系式。通过对不同孔径下的测量结果进行对比和归一化处理可以发现,对于二维超声速气膜而言,观察孔径尺寸并不会对获取的规律产生影响。
Due to the limitation of the wind tunnel experiment ability, it is very difficult for the experiment of aero-optical effect of a high-speed aircraft to be exactly the same as the actual flight situation. Reynolds numbers, as an important similarity criteria, are widely used in classical hydrodynamics wind tunnel experiments to study their effects on aero-optic effects and are of great significance for the establishment of aerodynamic optical similarity criteria. Based on the Π theorem, the variables that may affect the aerodynamic optical effect are analyzed. It is proved that the Reynolds number is a similar guideline that affects the aerodynamic effect. Through the innovative design of Reynolds number experimental device, the Reynolds number of the jet unit can be realized at 106 ~ 108 m-1 range of changes. By selecting eight typical Reynolds numbers and using the BOS-WS (BOSbased Wavefront Sensor) technique to measure the optical path difference of the corresponding states, the rms value of the optical path difference and the Reynolds number Power function relation. By comparing and normalizing the measurement results under different pore sizes, it can be found that for the two-dimensional supersonic gas film, observing the pore size does not affect the acquired law.