【摘要】 采用热色液晶定量测温技术对稳态及脉冲式空气－氮气圆形浸没射流冲击冷却换热进行了实验研究．脉冲射流的实验结果表明，对于喷嘴直径 Ｄ＝３ｍｍ的情形，无论脉冲频率高低，均无强化换热效果；对于Ｄ＝１０ｍｍ的情形，在较高Ｒｅ数时出现个别工况的驻点换热强化．脉冲射流表现出换热系数沿径向分布趋于均匀的特点．更多还原

【Abstract】 The heat transfer of intermittent nitrogen jet submerged in the air has been experimentally studied with liquid crystal displaying technique. The results revealed that the enhancement of heat transfer can not be obtained using a nozzle of D=3 mm. But when a nozzle of D = 10 mm is employed the enhancement heat transfer in the region of the stagnation point really occurred when the Reynolds number is large enough. Another notable characteristic of this kind configuration is that the distribution of the heat transfer coefficient is more even than that without intermittence.更多还原