气动光学效应研究进展

Research progress of aero-optical effect

光学成像探测技术是精确制导领域发展的重要方向,但由于光线在穿过密度变化的流场时会发生偏折、抖动和光程变化的现象,成像质量将严重下降,此即气动光学效应.研究气动光学效应同时具有明确的工程和学术价值,一方面以认识流场对光线传播的影响为基础,如何减弱气动光学效应已受到人们的广泛关注;另一方面由于光线传播携带了流场结构信息,光学探测也可以成为一种流场研究技术.从空气动力学和光学工程交叉的视角,对气动光学效应的研究进展进行综述.首先介绍了常见的气动光学评价参数,其次阐述了各种理论研究、实验、数值模拟方法,最后从流动导致图像畸变、减弱气动光学效应的方案和采用气动光学探测方法研究流场三个角度对现有文献进行总结,并讨论了气动光学领域数值模拟验证方法的困难和研究现状.最后结合气动光学效应的发展阶段对未来研究进行展望.

Optical imaging detection is an important research direction in the precision guide field.The quality of observation would be profoundly deteriorated due to the aberration,jitter,and change in optical path length when light propagates through the density-varying flowfield,videlicet,aero-optical effect.Investigation on such a field possesses both considerable engineering and academic values.On the one hand,based on the physical understanding concerning the impact of flow structures on light propagation,the methods for effective reduction of the aero-optical phenomenon have attracted widespread attention.On the other hand,optical interrogation has shown considerable potential in flowfield inspection since the light beam inevitably records the signature of flow structures.In the current study,recent advances of aero-optical effects have been reviewed in an interdisciplinary perspective of aerodynamics and optical engineering.The commonly-used evaluation parameters are introduced in the first place,followed by various theoretical,experimental,and numerical methods summarized in sequence.Whereafter,we put an eye on the research progress from three aspects,namely the impact of aero-optical effects on image aberration,the methods for reduction of aero-optical effect,and the flow structure examination via novel aero-optical detection method.An additional discussion focuses on the difficulty in numerical validation attempts for aero-optical problems.Prospects based on the development stages of aero-optical effects are proposed in the end.