Turbine last stage blade with forced vortex driven cooling air

摘要

A gas turbine engine with a turbine section having at least a first stage turbine blade and a last stage turbine blade. The first stage turbine blade includes cooling fluid passages therein in which a compressed cooling fluid, usually from the compressor section of the gas turbine engine, is passed through for cooling of the first stage blade. The last stage turbine blade includes cooling fluid passages therein, but draws the cooling air from an outside ambient pressure source instead of from a compressor. The rotation of the last stage turbine blade and rotor disk provides for a centrifugal force to drive the cooling air into the blade and through the blade for cooling thereof. No additional compression of the last stage cooling fluid is required. A cover plate with a plurality of impellers covers a back side of the last stage rotor disk and provides for an additional means to pump the ambient cooling fluid into the last stage blade.