Experimental Study on Film Cooling Flow Characteristics over Turbine Stator Blade at Different Setting Angles

Flow structures over a turbine stator blade with six rows of film cooling holes were measured at different blowing ratios and setting angles by PIV on a straight-flow low-speed wind tunnel bench, during which the flow velocity and turbulent kinetic energy were analyzed. Results show that the velocity gradient on suction surface is much higher than on pressure surface, and the velocity gradient increases with redu-cing setting angle and rising blowing ratio; the film adherence is influenced by setting angle, which reaches the best at β=70°, and the adherence on suction surface is stronger than on pressure surface; maximum turbulent kinetic energy exists on the top of bended coolant, i.e. at the boundary where mainstream mixes with jet flow; with the reduction of setting angle, the turbulent kinetic energy weakens gradually in the concentration area downstream the pressure surface, which reaches the minimum at β=70°, and with further reduction of the setting angle, the concentration area moves to the downstream region on the suction side, where the turbulent kinetic energy rises gradually.