Influence of Trailing Edge Coolant Ejection Rate and Cut-Back Length on Energy Loss and Shockwave Intensity of a Transonic Turbine Blade

Abstract

As part of our efforts to understand better ways and means to further improve jet engine performance, the influence of trailing edge coolant ejection rate and cut-back length on energy loss and shockwave intensity of a transonic turbine blade is numerically investigated with an exit Mach number of 1.2 for different coolant/main stream mass-flux ratios and cut-back lengths. Test results indicate both coolant ejection rate and cutback length have their optimum values, and the best ejection rate and the best cut-back length correlate with each other. From the view of minimizing the energy loss coefficient, the best ejection rate decreases with the increasing cut-back length. And from the view of minimizing the trailing edge shockwave intensity, a higher trailing edge coolant ejection rate and a longer trailing edge cut-back can reduce the shockwave intensity. It is therefore believed that these findings can of course facilitate the design of a trailing edge cooling system for transonic turbine blade to further improve jet engine performance. Moreover, trailing edge coolant ejection can be considered as an active flow control method at the same time.