基于红外热像技术的气膜冷却实验方法与应用

Experimental Methods and Application of Film Cooling Based on Infrared Thermography Technique

为了研究燃气轮机高温部件气膜冷却技术,设计了低速风洞试验台。用红外热成像温度测量技术,对平板单孔和排孔射流冷却特性进行试验研究。通过埋在平板内的高精度热电偶校正,得到准确的温度,并建立了校正关系。试验件为不锈钢平板,孔是35°圆柱斜孔,孔径D=4mm,长径比L/D=3.49,吹风比M=0.5～2.5。通过气膜冷却效率分布来描述气膜冷却效果,实验处理数据给出了在50℃、196℃、267℃时不同位置的气膜冷却效率,实验结果表明不同冷却空气量对气膜冷却效果的影响。

To investigate the film cooling performance on high temperature parts of gas turbine,the low speed wind tunnel has been design.Infrared thermography technique was used in the experiments of injection through a single and a row of holes in a flat plate.Accurate local temperature data are achieved by an in situ calibration procedure with the help of thermocouples embedded in the test plate,a correction relationship was established.Experiments were made of stainless steel and the diameter of film hole was 4mm,inclined 35deg,and Length/diameter was 3.49 and the blowing rate varied from 0.5 to 2.5.To describe the integral film cooling effect,detailed film–cooling effectiveness distributions at 50℃,196℃ and 267℃ were used for evaluating the thermal performance of cylindrical inclined film holes.The data present the influence of coolant injection rate on the film cooling performance of the cylindrical inclined film hole configuration.