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设计了高温低速风洞试验台,并利用红外热成像测温技术对平板单孔和排孔的射流冷却特性进行了试验研究.使用具有高精度和高空间分辨率的红外热像系统测量了平板表面温度,通过埋在平板内的热电偶校正红外热像仪温度并建立了校正关系.通过气膜冷却效率分布分析了气膜冷却效果,给出了在50℃、196℃和267℃时不同位置的气膜冷却效率.结果表明:在吹气比M=0.5时,动量较低的冷却射流易贴附于壁面形成一层冷却气膜对其加以保护;当吹气比M不断增大时,换热增强,冷却效率提高;当M=0.1左右时,孔下游冷却区域增大,有良好冷却效果;当M>2时,射流的动量已大于主流动量,射流孔附近两股换热增强,孔附近冷却效果好,而下游冷却面积变小.
A high temperature and low speed wind tunnel test bed was designed and the jet cooling characteristics of the single hole and the row of holes of the flat plate were experimentally studied by means of the infrared thermal imaging temperature measurement technique.The flat plate was measured by the infrared thermal imaging system with high precision and high spatial resolution Surface temperature, the temperature of the infrared camera was corrected by the thermocouple embedded in the flat panel and a calibration relationship was established.The effect of the film cooling was analyzed by the film cooling efficiency distribution, which showed that the film temperature was different at 50 ℃, 196 ℃ and 267 ℃ The results show that the cooling momentum with lower momentum is easily attached to the wall to form a cooling gas film to protect it at the blowing ratio M = 0.5. When the blowing ratio M is increasing , The heat transfer is enhanced and the cooling efficiency is improved. When M = 0.1, the cooling area on the downstream of the hole increases and has a good cooling effect. When M> 2, the momentum of the jet is larger than that of the main flow, , The cooling effect near the hole is good, and the downstream cooling area becomes smaller.