Experimental study of film cooling characteristics for dust-pan shaped holes on pressure side in a turbine guide vane

In order to study film cooling characteristics for single dust-pan shaped hole rows at different locations on turbine blade pressure side, film cooling effectiveness for four rows of dust-pan shaped holes on pressure side in a turbine guide vane was measured at short-duration transonic heat transfer wind tunnel, which are at 10.7%, 21.1%, 36.1%, 64.3% relative arc respectively, and the distribution of film cooling effectiveness at different mainstream Reynolds number, Mach number, blowing ratio and position of the holes was obtained. The results indicate that the film cooling effectiveness decreases with the Reynolds number increasing for hole 1 and hole 2 near the leading, while the effectiveness is the lowest at low Reynolds number (Re=2.0×10⁵) case for hole 3 and hole 4 near the trailing, where the change of Reynolds number has small effect on the effectiveness at middle and high Reynolds number(Re=4.0×10⁵, 6.0×10⁵) case. Spatially averaged adiabatic effectiveness over the range displacement-to-diameter x/d=0 to 40 for all holes increases and then decreases with the blowing ratio increasing, and the highest averaged value is obtained at the blowing ratio of 1.0. Film cooling effectiveness for the holes near the trailing is higher compared with the case of the holes near the leading, but it decreases faster with the distance increasing.