航空发动机尾喷温度场的背景纹影光学中心校正OA

To address the projection offset and axisymmetric temperature-field reconstruction distortion caused by camera optical-axis misalignment in background-oriented schlieren(BOS)technology,this pa-per proposed an optical center calibration method based on geometric optical modeling.Conventional methods assumed strict alignment between the camera optical axis and the flow axis,neglecting unavoid-able angular deviations in practical installation.In this work,an accurate geometric model incorporating optical-axis tilt was established,from which an analytical mapping between actual projection coordinates and ideal sensor coordinates was derived.This enabled precise deflection-angle calculation under mis-aligned conditions while maintaining a single-camera axisymmetric measurement architecture.By integrat-ing the Abel inverse transform and the Gladstone-Dale relation,a complete reconstruction chain from de-flection angles to refractive-index fields and finally to temperature fields was achieved.Experimental vali-dation was conducted within a misalignment range of±6°.The results show that under a+6° tilt condi-tion,the average temperature deviation is reduced from 18.26 K using the conventional method to-0.94 K with the proposed approach,corresponding to an improvement of approximately one order of magnitude in accuracy.The method significantly enhances the measurement reliability of BOS under non-ideal instal-lation conditions and provides an effective calibration tool for high-precision,robust optical diagnosis of aero-engine exhaust temperature fields.