高旋转数下带肋回转通道的换热特性

为匹配真实发动机转子叶片的工作条件,将实验回转通道气体压力提高到500kPa以上,使雷诺数和旋转数范围分别扩展到10000~70000和0~2.08.在此基础上通过实验方法研究了高旋转数下带45°倾角斜肋的方形截面回转通道的换热特性.结果表明:回转通道的第1通道前缘面传热系数随旋转数的增大先减小,在达到临界旋转数后换热随旋转数增大而增强;低旋转数下,回转通道的第2通道前后缘面换热差异较小,随着旋转数的增大,前缘面换热始终强于后缘面,这种换热特性与光滑通道完全不同. 

Heat transfer characteristics in U-shaped rib-roughened channel at high rotation numbers

To match the rotor blade of real engine operating condition, the Reynolds and rotation number range of current experiment were expanded from 10000 to 70000 and 0 to 2.08 by increasing the pressure of the air in the U-shaped channel to 500kPa. Experiments were conducted to investigate the heat transfer characteristics in a square U-shaped channel with inclined 45 deg ribs. Results indicated that,in the first passage of the U-shaped channel, heat transfer coefficient of leading wall firstly decreased with the increase of the rotation number, then increased with the rotation number after reaching a critical value; in the second passage of the U-shaped channel, the difference of heat transfer coefficient between leading and trailing walls was not obvious at low rotation number, but kept increasing with the rotation number to a higher level; the heat transfer of leading wall behaved better than trailing wall, which was totally different from that of a smooth channel.