高速混合流场下星光偏折的观测实验  

Observation experiment on star-light deflection of star-points under high-speed mixing flow

作　　者：陈冰[1] 陈少杰 陈虓[1,2] 李崇辉[1] 郑勇[1] Chen Bing;Chen Shaojie;Chen Xiao;Li Chonghui;Zheng Yong(Information Engineering University,Zhengzhou 450001,China;Xi'an Satellite Control Center,Xi'an 710043,China)

机构地区：[1]信息工程大学,河南郑州450001 [2]西安卫星测控中心,陕西西安710043

出　　处：《红外与激光工程》2023年第9期212-221,共10页Infrared and Laser Engineering

基　　金：国家自然科学基金项目(11673076,41604011);河南省自然科学基金项目(212300410421)。

摘　　要：天文导航是一种重要的飞行器自主导航手段。在高速飞行器上进行的观测,不可避免地会受到窗口外侧高速流场的扰动,使得星敏感器捕获的星点图像出现偏移、模糊等退化现象,影响天文定位定姿精度。对星图退化的计算和校正的研究多基于计算机仿真结果。文中建成了一座可在实验段中生成马赫2.5/3.5混合层结构的小型静风洞,以直径10 m的室内穹顶上的仿真星点为观测对象,透过实验段中不同位置的流场进行了星点观测和中心点解算,获得了星点图像受到流场扰动的数据,并将其与计算机仿真结果进行对比。结果表明:导航星光偏折量高于计算机仿真的估计值。在喷口近端,高速混合流场对星光偏折的扰动较大,垂直流场方向的偏折均值小于0.5″,沿流场方向偏离均值为3.85″,最大接近4.89″;在喷口远端,垂直方向星光偏折均值为-1.36″,沿流场方向偏折均值约-0.49″,最高达-2.69″。近端星光偏折变化幅度较小,稳定性较远端更强,有利于建模校正。该实验对校正仿真模型、优化高速流场下的天文定姿精度有着重要的意义。Objective Celestial navigation is an important method of autonomous navigation.Astronomical observation of high-speed aircraft will be disturbed inevitably by the high-speed flow nearby the observation window,which causes the star maps degradation like displacement and blurring.And this will lead to a decrease in the accuracy of the stars center,which will have a direct effect on the accuracy of astronomical attitude determination.At present,most studies on the calculation and correction of star map degradation are based on computer simulation,whose results are greatly affected by the configuration of model parameters and may not be consistent with the real physical process.Therefore,it is necessary to construct the physical experimental observation conditions of the influence of high-speed flow on star-light deflection and to carry out experimental research.Methods A small static wind tunnel is built,which can generate a Mach 2.5/3.5 mixing layer structure in the test section.The calibrated simulated star-points on the indoor dome with a diameter of 10 m are measured through the high-speed flow,and the star centroids are extracted to collect the data of imaging displacements by the real flow.The data of star image disturbed by the flow field are obtained and compared with the computer simulation results.Results and Discussions The deflection by flow is greater than the estimated value of computer simulations.At the near end of the tunnel nozzle,the high-speed mixing layer makes a large star-light deflection.The mean deflection in the vertical direction of the flow field is less than 0.5″,and that in the direction of the flow field is 3.85″,and the maximum is close to 4.89″(Fig.8).At the far end,the mean deflection in these two direction is-1.36″and-0.49″respectively(Fig.9).The variation of starlignt deflection at the near end is smaller and more stable than that at the far end,which is conducive for modeling correction(Fig.10).Conclusions A star-points observation system under the high-speed flow was c

关 键 词：高速流场 马赫2.5/3.5混合层 小型风洞 室内穹顶 星光偏折 

分 类 号：V249.32[航空宇航科学与技术—飞行器设计]