Modulated turbine cooling system

Abstract

A modulated flow transfer apparatus for transferring a fluid flow from a static element to a rotor of a gas turbine engine has an annular static inducer for accelerating the fluid flow in a substantially circumferential direction. The inducer has an annular row of identical first and second flow passages with first and second inlets respectively and outlets. First and second flow means direct first and second portions of the flow to the first and second flow passages, respectively. A valve is used for selectively modulating the second portion of the flow which together with a controller may be used for selectively preventing the second portion of flow from flowing through the second flow passages during a first cruise of engine operation and allowing substantially unrestricted flow therethrough during a takeoff mode of engine operation. The second flow means preferably includes an inducer manifold disposed between the valve and the second inlets. Exhaust ducts connect corresponding ones of the second inlets to the inducer manifold. The inducer manifold is preferably disposed inside a plenum used to feed cooling air to the first passages.

Dependencies are inferred from the claim text.