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针对超声速飞行器在大气中飞行时由于气动光学效应产生的成像偏移,推导了光线偏折角和流场折射率梯度之间的关系,给出了小入射角情况下,离散折射率场光线偏折角的一种计算方法;利用不同流场的计算流体力学数据计算出对应的折射率场;使用光线追迹法得到光线通过不同流场后的偏折角和传播路径上的折射率梯度分布。仿真结果表明,新的偏折角计算方法所得结果在入射角小于30°时与Runge-Kutta和Snell光线追迹法具有很好的一致性;同一高度下小入射角时,光线的偏折角并不随着飞行速度的增加而增加,而是基本保持稳定;光线通过流场的偏折是正负折射率梯度区域共同作用的结果,负的折射率梯度区域可以减少光线偏折,起到部分“校正”作用。
Aiming at the imaging migration of supersonic aircraft in the air due to aerodynamic optics, the relationship between the deflection angle of light and the refraction gradient of the flow field is deduced. Under the condition of small incident angle, the deflection angle of the discrete refractive index field The calculation of the corresponding refractive index field is based on computational fluid dynamics data of different flow fields. The ray deflection method is used to obtain the deflection angle and the gradient of refractive index on the propagation path. The simulation results show that the results obtained by the new deflection angle calculation method are in good agreement with the Runge-Kutta and Snell ray tracing methods when the incident angle is less than 30 °. When the incident angle is small at the same height, the deflection angle does not follow The velocity of flight increases, but basically remains stable. The deflection of light through the flow field is the result of the interaction of positive and negative gradient of refractive index. The negative gradient of refractive index can reduce the deflection of light and play a part of “ Correction ”role.