DEVELOPMENTS IN AIR COOLING OF GAS TURBINE VANES AND BLADES

Over the history of gas turbine engine development, improvements in engine performance are closely tied to increases in the level of tolerable turbine inlet temperatures. The ability to operate at increasingly high temperatures has been the result of both improvements in materials capability and advances in the art of cooling the hot section components. For propulsion engines and their derivatives the cooling medium is air supplied from the compressor stages, requiring an expense of engine power. The hot section airfoils, particularly the first stage vanes and blades, consume a significant fraction of the total engine cooling air. Designers are continuously faced with the task of making more effective use of the coolant to improve either performance or durability or both. The design process requires detailed knowledge of heat transfer and flow friction characteristics for present and candidate future cooling schemes. Typical current cooling schemes and associated research work directed to future improved designs are discussed.© 1983 ASME