涡轮叶片表面气膜冷却的传热实验研究

对压力面和吸力面各有双排气膜孔冷却的涡轮导向叶片表面进行了详细的传热实验研究,在不同吹风比下获得了当地气膜冷却效率和换热系数,结合流场测量结果分析了叶片表面冷却和换热规律。结果表明不同孔排位置叶片表面气膜冷却效率和换热规律有很大不同,孔排位置一定时,冷却效果主要由吹风比决定。结果还表明尽管冷气喷射使型面换热系数随吹风比的增大而显著增大,气膜冷却还是能有效的降低型面的热负荷,其中以中吹风比喷射时冷却效果最为显著。

Turbine Blade Surface Heat Transfer and Film Cooling Measurements in a Turbine Cascade with Injection on Surface

Detailed heat transfer measurements were conducted on the turbine blade surface of a large scale low speed turbine cascade with injection on the surface of turbine blade.Local film cooling effectiveness and heat transfer coefficient with coolant injection were determined at different blowing ratios.In conjunction with the previous measurements of the flow field,the behaviours of turbine blade surface film cooling and heat transfer were studied.The results show that turbine blade surface film cooling and heat transfer are different greatly in different hole array position.The coverage of the coolant on the surface is mainly determined by blowing ratio for same geometry.It was also observed that coolant injection made the overall averaged heat transfer increase remarkably with blowing ratio and then made the thermal loads on the surface decrease effectively.