出流孔位置对带肋矩形通道换热特性的影响

Influence of bleed hole location on heat transfer inrectangular channels with ribs

关键词:  热色液晶  出流孔  肋  传热系数  出流孔位置

Key words:  Thermochromic liquid crystal  Bleed ratio  Rib  Heat transfer coefficients  Hole location

摘要:

为了获得涡轮叶片内冷带肋通道出流孔位置设计参数,采用热色液晶瞬态测量技术研究带有肋和单排溢流孔的内流通道的换热特性,分析出流孔位置对矩形通道壁面换热特性的影响规律。矩形内流通道进口雷诺数Re变化范围是6×10⁴~8×10⁴,通道总出流比Br为0.3~0.60,出流孔分别位于距前肋0.25,0.50,0.75倍肋距处。实验结果表明:出流孔和肋端附近换热得到强化,带肋和出流孔壁面换热最强。在不同孔位置下,带肋无出流孔壁面换热变化不大。出流孔位于肋后0.25倍肋距时,带肋和出流孔壁面和光滑面换热效果最好。

Abstract:

Measurements of endwall heat transfer in the rectangular passage with ribs and bleed holes were made by using transient liquid crystal technique. The effects of bleed hole location on the heat transfer have been investigated. The ranges of the main-flow Reynolds number are 6×10⁴~8×10⁴ and the bleed ratio are 0.3~0.6. The bleed holes were located at 0.5,0.50 and 0.75 rib distance downstream from the front rib. Detailed distributions show distinctive peaks in heat transfer levels around bleed holes and on rib turbulator tips.In given bleed hole location,heat transfer enhancement factor on the surface with ribs and bleed holes is higher than other surfaces. Changes in hole location do not significantly affect heat transfer enhancement factor on the surface with rib. Heat transfer enhancement factor on the smooth surfaces and the surface with ribs and bleed holes increases while the bleed holes are close to the front rib.