An Experimental Study on Aerodynamic Performance of Turbine Nozzle Guide Vanes With Trailing-Edge Span-Wise Ejection

The present experimental study is to examine the influence of trailing-edge coolant ejection with the span-wise inclination on the aerodynamic loss of turbine nozzle guide vanes. This study uses a cascade of five vanes located in the test section of a low-speed wind tunnel. The vanes have the profile of high-pressure nozzle guide vanes, and the central vane is equipped with the internal cooling and the trailing-edge coolant ejection. The coolant is ejected through trailing-edge slots that are inclined in the span-wise direction at angles varying from 0 deg to 45 deg in 15 deg increments. The results indicate an optimum ejection rate, at which the aerodynamic loss is minimum. There is a little variation in loss as the span-wise inclination is varied when the ratio of coolant to mainstream gas mass flow rate is less than 1.5%. For higher coolant flow rates, however, the loss increases with increases in the span-wise ejection angle.