液晶热像测量精度分析及其在湍流传热研究中的应用

Measurement Accuracy and Application of Liquid Crystal Thermography Technique in Turbulent Flow Heat Transfer

通过开展液晶热像校准实验研究,分析了各测量参数对液晶热像测量精度的影响,得到了提高测量精度的有效方法,并对液晶热像技术应用于湍流传热研究进行了分析和讨论.实验结果表明,采用液晶图像滤波技术、控制液晶涂层厚度(>20μm)、减小光源照射角度以及提高液晶涂层的喷涂质量都有利于提高液晶热像的测量精度.最后,介绍了稳态和瞬态液晶热像技术在航空发动机透平叶片湍流对流冷却中的应用.

By conducting a calibration experiment, the parameters affecting the measurement accuracy of the liquid crystal thermography has been analyzed, and the methods for improving the measurement accu- racy have been developed. Additionally, the application of the liquid crystal thermography technique in the study of turbulent flow heat transfer has been discussed. The experimental results showed that using the color imaging processing techniques, properly controlling the coating thickness （over 20 /~m）, keeping the lighting angle as small as possible, and using a finely prepared thermochromatic liquid crystal （TLC） coat- ing can distinctively improve the measurement accuracy of the liquid crystal thermography. Finally, the applications of the steady and transient liquid crystal thermography technique in the study of the turbulent flow heat transfer have been described, which is related to the convective cooling of the aero-engine turbine blade.