出口马赫数0.81-1.01下涡轮导向叶片全气膜冷却特性研究

Investigation on full-coverage film cooling effectiveness of turbine vane with exit Mach number from 0.81 to 1.01

通过瞬态热电偶测量方法研究了涡轮导叶叶片全气膜换热系数和气膜冷却效率。试验叶片共有13排气膜孔,气膜孔排由前后2个腔供气,前腔二次流与主流流量比为5.06%,后腔为1.14%。为匹配真实发动机工作条件,叶栅进口雷诺数试验范围为1.7×10^5-5.7×10^5,出口马赫数范围为0.81-1.01。试验获取了叶片表面压力系数和换热系数分布规律,并研究了叶栅进口雷诺数和出口马赫数对叶片全气膜冷效分布的影响。结果表明：气膜孔下游的换热系数和气膜冷效较高;主流雷诺数的增加对冷却效率的提升有积极作用,特别是在叶片吸力面,而马赫数对叶片表面气膜冷效影响甚微。

Heat transfer coefficient and film cooling effectiveness are investigated on a turbine vane employing the transient thermal couple technique.There are 13 rows of film cooling holes placed on the test blade.The cooling gas through film holes is supplied by two plenums,with mass flow ratio of 5.06%in the first plenum and 1.14%in the second.To match the real engine operating condition,the range of the inlet Reynolds number and the exit Mach number of the current experiment are 1.7×10^5-5.7×10^5 and 0.81-1.01,respectively.Heat transfer coefficient distribution is obtained,and effects of Reynolds number and Mach number to film cooling effectiveness distribution are investigated.The results show that heat transfer coefficient and film cooling effectiveness are higher in the near hole region.Film cooling effectiveness increases as inlet Reynolds number increases,especially on the pressure side and suction side,while the effect of exit Mach number to film cooling effectiveness is not obvious.