Gas turbine engine cooling airflow modulator

Claim 1

In a gas turbine engine including a centrifugal compressor, a combustor, and a turbine section being coaxially disposed in an engine casing, said compressor being disposed forward of said combustor and said turbine section being disposed aft of said combustor, said compressor being effective for supplying compressor discharge air for cooling said turbine section, a system for modulating said cooling air to said turbine section comprising: an outlet of said compressor disposed radially outwardly with respect to said combustor and facing in an aft direction; a duct having a first and second ends, said first end being disposed radially outwardly of said combustor and said second end being disposed radially inwardly thereof, and an inlet port disposed at said first end and forward of said compressor outlet; a manifold disposed in flow communication with said second end of said duct for collecting cooling air discharged therefrom for providing a source of cooling air for cooling said turbine section; a tangential flow accelerator disposed in flow communication with said manifold and effective for directing said cooling air to said turbine section; and valve means effective for modulating flow of said cooling air in said duct and including an actuator disposed radially outwardly of said casing, an actuator arm extending from said actuator through said casing, and a valve positionable in said duct for modulating airflow therethrough and being operatively connected to said actuator arm.