氢氧火箭发动机羽烟紫外辐射参数反演研究

Inverse problem of ultraviolet radiation characteristic parameters in hydrogen-oxygen rocket motor plume

针对氢氧火箭发动机羽烟紫外辐射特性参数分析,提出一种基于紫外CCD(change coupled de-vice)相机采集的单幅辐射图像,同时反演羽烟内紫外辐射源项和吸收系数的方法.该方法将羽烟简化为发射-吸收轴对称介质,通过对辐射图像数据进行Able变换得到三维介质内辐射强度分布,利用最小二乘法将反演问题转化为使计算得到的与Abel变换得到的辐射强度误差最小的最优化问题,然后利用共轭梯度法求解该最优化问题.通过在求解正问题得到的准确值的基础上添加随机噪声,模拟辐射图像数据,分析了测量误差对算法反演精度的影响.结果表明:该算法对测量误差不敏感,能够准确的重建羽烟内的辐射源项和吸收系数分布.

An inverse radiation analysis was presented for simultaneous estimation of the radiative source term and absorption coefficient distribution in the plume of hydrogen-oxygen rocket motor from the knowledge of a single ultraviolet radiation image captured by the CCD camera. Considering the plume as absorbing-emitting cylindrical symmetry media with transparent boundaries, after applying Abel transform to the image data, the inverse prob- lem was formulated as an optimization problem that minimizes the errors between the radia- tion intensities calculated and the experimental data with Abel transform, and the conjugate gradient method was used to solve the optimization problem. The effects of measurement er- rors on the accuracy of the estimation were investigated, and the measured data were simula- ted by adding random errors to the exact solution of the direct problem. Test results show that the radiation characteristic parameters can be estimated accurately, even for data with measurement error.