采用窄带热敏液晶瞬态单色捕捉技术测量叶片全表面传热系数，以预先加热被测叶片并在主流中快速冷却的方法引入温度阶跃，利用3台3CCD（电荷耦合元件）相机对叶片表面的不同区域进行图像采集记录，将图像坐标转换至叶片空间坐标，通过后处理得到叶片表面传热系数。由实验结果分析可知，叶片前缘区域传热系数最大值位于加速最剧烈处，在吸力面8／L约为0．22处产生轻微流动分离，促使边界层发生转捩，传热系数突然增大。
Heat transfer coefficients on the turbine guide vane surface are measured by using the narrow-band liquid crystal single-color capture technology. The vane is preheated and then suddenly cooled by the main flow to introduce the temperature step change. Three 3CCD （Charge Coupled Device） cameras are used to record corresponding images of different regions of the vane surface, and the images are transformed from the image coordinate system to the spatial coordinate system of the vane. The experimental results showed that the local maximum heat transfer coefficient in the leading edge area occurs at the position where the flow is most accelerated, and that a slight flow separation occurs at the position about s/L= 0.22 on the suction surface, which results in boundary-layer transition and a rapid increase of heat transfer coefficient.
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