摘要
通过系统集成与开发,研究了基于背景纹影(BOS)的高分辨率气动光学畸变测量方法。分析了PIV方式的BOS系统结构与特征。在BOS中,背景点的位移受实验装置的几何参数影响,通过调整这些参数能够改变BOS成像系统的分辨率以及观测区域的大小,这是传统纹影难以实现的。通过简化光路,定量分析了BOS的灵敏度与分辨率之间的相互制约关系。在搭建BOS系统的基础上,研究了蜡烛火焰上方热对流导致的气动光学效应,并根据光线偏折角与光程差之间的关系,实现了气动光学波前重构。结果表明,蜡烛火焰造成的平面波前畸变较好的反映了流场非均匀性带来的气动光学效应,而且其空间分辨率远远高于传统的干涉测量技术。
The high resolution aero-optical aberration measuring method based on BOS was studied via systematic integration and development.The structure and characteristic of the PIV-type BOS system were analyzed.Because the displacement of background dots in BOS relates with the configuration of BOS,the spatial resolution and area of observation window of BOS can be adjust by its configuration,which is superior to the traditional schlieren.By simplifying the optical configuration of BOS,the relation between sensitivity and resolution was analyzed quantitatively.According to the fundamentals of BOS,it can be seen that the aero-optical aberration field of BOS is vectorizable and reveals high spatial resolution,from which both the magnitude and the direction of aberration of the object image can be extracted.The quantificational characteristic of BOS provides important original data for the measurement of the flowfield and aero-optical parameters.With these data,the wavefront of aero-optical aberration can be computed,moreover,the point spread function,Strehl ratio and other aero-optical parameters can be derived.The aero-optical effectiveness induced by the heat convection flow field of a candle flame was studied with a BOS apparatus.According to the relation between refractive angle and optical path difference,the wavefront of aero-optical aberration was reconstructed.The results show that the aero-optical effectiveness led by the candle flame was accurately reflected by the wavefront distribution,the spatial resolution of which was far better than the traditional interferometer.
出处
《空气动力学学报》
EI
CSCD
北大核心
2010年第5期609-612,共4页
Acta Aerodynamica Sinica
作者简介
张红朝（1976-），男，湖北省大悟县人，博士研究生，主要研究方向为实验空气动力学．E—mail：ezhc@263．net
