纹影法轴对称温度场高精度测量

High Precision Measurement of Axisymmetric Temperature Fields by Schlieren Method

针对提高纹影法测温精度的需求,提出了一种基于Abel算法改进型轴对称流场的温度反演算法。该方法利用插值技术处理离散偏折角数据,生成连续函数,精确计算待测流场的折射率。通过比较插值法、离散法与两点法的折射率反演结果,验证了插值法在拟合理想高斯函数方面的优越性。实验结果表明,纹影与热电偶测量温度的平均相对误差小于12℃,相比于多光谱和RGB联合测温,纹影测温平均精度提高了6%,证实了该方法在提高温度分布测量精确度方面的有效性,为纹影法测温精度的提升提供了新思路。

In order to improve the accuracy of thermometry by the schlieren method,the paper presents a novel algorithm based on an enhanced Abel technique for axisymmetric flow field analysis.This algorithm utilizes interpolation techniques to process the discrete deflection angle data and construct a continuous function for accurate calculation of the refractive index of the target flow field.A comparison of the refractive index inversion obtained by the interpolation,discrete and two point methods shows that the interpolation method is superior in fitting ideal Gaussian functions.Experimental results show that the average relative error between schlieren measurements and thermocouple readings is less than 12℃.The average accuracy of thermometry by the schlieren method is improved by 6%compared to multi spectrum and RGB based temperature measurements,validating its effectiveness in enhancing the precision of temperature distribution measurement.This study provides a new perspective for improving the accuracy of schlieren temperature measurements.