高湍流度时全气膜涡轮叶片表面冷却和换热特性的实验研究

An experiment was performed in the transonic wind tunnel to obtain the film cooling and heat transfer characteristics of a fully cooled turbine vane at high mainstream turbulence intensity condition. The effect of mass flow ratio (MFR) and Reynolds number (Re) on the film cooling effectiveness and heat transfer coefficient was studied. Five rows of cylindrical holes were arranged on the leading edge, three rows and six rows of cylindrical holes were provided on the suction side and pressure side, respectively. The experimental results were measured by the thermocouples embedded in the middle span of the vane. In the experiment, the inlet Reynolds number based on the chord length ranged from 3.0×10⁵ to 9.0×10⁵, the exit Mach number of the cascade was 0.8, the mass flow ratio varied from 5.5% to 12.5% and the mainstream turbulence intensity was 14.7%. Experimental results show that the increase of inlet Reynolds number significantly strengthens the heat transfer on the vane surface and leads to advanced laminar-to-turbulent layer transition position. In the region of S/C >0.2 on the suction side (S/C is the ratio of local arc length to the chord length), the film cooling effectiveness is significantly affected by MFR, increased MFR leads to decreased film cooling effectiveness when MFR is larger than 7.7%. The heat transfer coefficient of this region is slightly affected by MFR at low and medium Reynolds number conditions, while it increases with the increase of MFR at high Reynolds number condition. The film cooling effectiveness in the region of S/C<-0.7 on the pressure side increases with MFR increasing, while it is less affected by MFR for -0.7<S/C<-0.4. Increased MFR results in enhanced heat transfer coefficient on the entire pressure side. Compared with other regions of the vane surface, the film cooling effectiveness on the suction side and the rear half of pressure side is obviously affected by the Reynolds number.