An air-cooled turbine blade having special provisions for cooling the leading edge of the blade by introducing air under a leading-edge cap was investigated in a modified production turbojet engine.nThe cooling effectiveness was determined over a range of engine speed from 4000 to 11,350 rpm. The cooling-air flow per blade was varied from about 0.01 to about 0.1 pound per second. The results indicated effective cooling of the leading edge of the blade. For example, at an engine speed of 10,000 rpm, a coolant- to gas-flow ratio of 0.054, and an effective gas temperature of 1000° F, the leading-edge temperature was about 400° F, which is about 230° F cooler than the most effectively cooled leading-edge configuration previously investigated. The cooling-air pressure loss through the blade, based on coolant flow rate, was the lowest of any cooled-blade configuration so far investi¬gated.
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