The Aerodynamics of a Turbine Cascade With Supersonic Discharge and Trailing Edge Blowing

Abstract

This paper presents a very thorough experimental investigation of a supersonic turbine cascade with thick trailing edges designed for trailing edge ejection of cooling air. Experiments were performed on a supersonic turbine cascade designed for a deflection of 135 deg and outlet Mach number 1.2. The blade section was designed for high rates of cooling air flow, the cooling air being ejected through a slot in a relatively thick trailing edge. Results were obtained for both the blown cascade and the equivalent cascade with solid trailing edges. The flow was found to be substantially different from that assumed in the design method, the effect of reduced base pressure at the trailing edges being especially important. Theoretical considerations lead to an improved model of the flow and in particular the high total pressure loss measured experimentally is largely explained.