改进的瞬态实验方法对涡轮转子端壁换热的研究

改进瞬态实验方法,使实验件的初始温度在上下表面间形成线性分布,降低了对实验设备和操作的要求.以此方法研究涡轮转子端壁的流动和换热情况,实验结果表明,端壁表面的换热强度受来流雷诺数和端壁二次流结构的共同影响.来流雷诺数增加,端壁整体换热增强;二次流的影响,导致端壁表面存在若干局部传热强化的区域,包括前缘马蹄涡形成的区域、马蹄涡分支覆盖的区域、靠近吸力面一侧通道涡生成的区域、以及角涡产生的位置.实验测得的结果符合对端壁二次流结构的现有认识. 

Heat transfer study on a turbine rotor endwall by an improved transient experiment method

Based on a new scheme of transient experiment,the test item has a linear initial temperature distribution between the upper and lower surfaces,so the equipment and operation could be simplified.Studies were done on the flow and heat transfer of a turbine rotor endwall.Results show that the endwall heat transfer is determined by the mainstream Reynolds number,together with the complex secondary flow pattern in the cascade passage.The overall heat transfer rate of the endwall is intensified with the improvement of the mainstream Reynolds number,while the secondary flow induces locally higher heat transfer rate in some regions,including:the region of horseshoe vortex near the leading edge,region where branches of horseshoe vortex pass by,the region downstream near the suction side where passage vortex occurs,and the region where corner vortex occurs.Results show good accordance with current knowledge of the endwall secondary flow.