초록 ▼

Clearance control between an outer air seal of a gas turbine engine and an internal, turbine section of the engine is controlled by selectively modulating a cooling air supply that is directed to selected portions of the air seal supporting structure to control its thermal growth. Impingement of the

Clearance control between an outer air seal of a gas turbine engine and an internal, turbine section of the engine is controlled by selectively modulating a cooling air supply that is directed to selected portions of the air seal supporting structure to control its thermal growth. Impingement of the cooling air causes contraction of the seal structure, thereby lessening the clearance for the purpose of improving engine performance. The flow of cooling air is modulated in response to engine speed and engine altitude to maintain relatively low clearance during critical periods of engine operation.

대표청구항 ▼

In a gas turbine engine having an engine case and a rotating machinery section rotatably supported therein, seal means circumferentially surrounding the rotating machinery section and attached to said engine case, and a clearance control comprising means for directing cooling air on said engine case

In a gas turbine engine having an engine case and a rotating machinery section rotatably supported therein, seal means circumferentially surrounding the rotating machinery section and attached to said engine case, and a clearance control comprising means for directing cooling air on said engine case for cooling thereof, thereby controlling clearance between said rotating machinery and said seal means, an improvement comprising: cooling air control means for varying the amount of cooling air directed on said engine case, said cooling air control means comprising a bypass line in flow communication with a case cooling line for directing a portion of said cooling air from said case cooling line for the purpose of varying the amount of air provided to said clearance control, said bypass line being provided with a bypass line valve that is opened during appropriate engine operations to allow cooling airflow to enter said bypass line, said bypass line valve being controlled by fluid pressure; a pressurized fire extinguishing source incorporated into said engine; and a pressure line connecting said pressurized fire extinguishing source to said bypass line valve for the purpose of closing said bypass line during release of fire extinguishing material.