Air modulation apparatus

Claim 2

In a gas turbine engine having a cooling air circuit therein for directing cooling air to an engine rotor component, an air modulation apparatus comprising: (a) an annular nozzle including a plurality of circumferentially spaced vanes and a plurality of flow passages, each of said flow passages being disposed between and defined by adjacent ones of said vanes and each flow passage having an inlet and an outlet, each said inlet being effective for receiving a portion of said cooling air; (b) valve means effective for covering only a portion of said nozzle to prevent flow to a first portion of said plurality of flow passages and thereby reducing the amount and increasing the velocity of cooling air exiting freely from a remaining portion of said plurality of flow passages of said nozzle not provided with valve means; and (c) actuation means for opening and closing said valve means.

Claim 3

The apparatus of claim 1 wherein said valve means includes an arcuate sealing surface for abutting a portion of said conduit.

Claim 4

The apparatus of claim 2 wherein said arcuate sealing surface abuts a radially outer portion of said nozzle when in a closed position.

Claim 5

The apparatus of claim 1 wherein said actuation means includes fail safe means for opening said valve means in the event of predetermined conditions.

Claim 6

The apparatus of claim 1 wherein said valve means comprises a plurality of valve doors spaced at locations about said nozzle.

Claim 7

The apparatus of claim 5 wherein said actuation means is effective for independently opening and closing said valve doors.

Claim 8

The apparatus of claim 3 wherein said valve doors are hinged for opening and closing through radially pivotal movement.

Claim 9

The apparatus of claim 7 wherein said actuation means comprise radially movable actuation arms attached with said valve doors.

Claim 10

The apparatus of claim 8 further including fail safe means comprising resilient members disposed around each of said actuation arms for effecting radial movement of said actuation arms to open said valve doors in the event of predetermined conditions.

Claim 11

The apparatus of claim 8 wherein said actuation arms have cross-sectional shapes elongated in a direction of air flowing across said actuation arms.

Claim 12

The apparatus of claim 8 wherein said nozzle includes a generally radially extending flange and said valve doors are hinged to said flange.

Claim 13

The apparatus of claim 8 wherein said valve doors and said actuation arms include vibration damping means.

Claim 14

The apparatus of claim 12 wherein said vibration damping means comprise a resilient member disposed between each of said actuation arms and the valve door to which the actuation arm is attached.

Claim 15

The apparatus of claim 8 wherein said actuation means include control means for effecting radial movement of each of said actuation arms in response to preselected engine operating conditions.

Claim 16

The apparatus of claim 14 wherein said control means is responsive to turbine inlet temperature and fuel flow.

Claim 17

An air modulation apparatus according to claim 1 wherein said nozzle comprises a tangential flow accelerator effective for accelerating and discharging said cooling air in a direction generally tangential to each said outlet.

Claim 18

An air modulation apparatus according to claim 1 wherein said inlets and outlets of said flow passages face in a generally radial direction.

Claim 19

An air modulation apparatus according to claim 17 wherein said inlets are disposed radially outwardly with respect to said outlets.

Claim 20

An air modulation apparatus according to claim 1 wherein said air modulation apparatus is effective for directing cooling air from a compressor to a turbine of said engine.

Claim 21

In a gas turbine engine having a cooling air circuit for directing cooling air from a compressor to a turbine within said engine, an air modulation apparatus comprising: (a) an annular nozzle including a plurality of circumferentially spaced vanes and a plurality of flow passages, each of said flow passages being disposed between and defined by adjacent ones of said vanes and each flow passage having an inlet and an outlet, each said inlet being effective for receiving a portion of said cooling air; (b) a plurality of valve doors spaced apart at locations about the circumference of said nozzle, each of said valve doors including an arcuate sealing surface for, when in a closed position, abutting a radially outer portion of said nozzle to prevent flow to a first portion of said plurality of flow passages and thereby reducing the amount and increasing the velocity of cooling air exiting freely from a remaining portion of said plurality of flow passages of said nozzle not provided with valve doors, said valve doors being hinged for opening and closing by radially pivotal movement; (c) a plurality of radially movable actuation arms, each of said actuation arms being attached with one of said valve doors for opening and closing said valve doors; (d) control means for effecting radial movement of each of said actuation arms in response to preselected engine operating conditions; and (e) a plurality of resilient members disposed around said actuation arms for effecting radial movement of said actuation arm to open said valve doors in the event of predetermined conditions.

Claim 22

In a gas turbine engine having a cooling air circuit for directing cooling air from a compressor to a turbine within said engine, an air modulation apparatus comprising: (a) an annular nozzle including a plurality of circumferentially spaced vanes and a plurality of flow passages, each of said flow passages being disposed between and defined by adjacent ones of said vanes and each flow passage having an inlet and an outlet, each said inlet being effective for receiving a portion of said cooling air; (b) a plurality of valve doors spaced apart at locations about the circumference of said nozzle, each of said valve doors including an arcuate sealing surface for, when in a closed position, abutting a radially outer portion of said nozzle to prevent flow to a first portion of said plurality of flow passages and thereby reducing the amount and increasing the velocity of cooling air exiting freely from a remaining portion of said plurality of flow passages of said nozzle not provided with valve doors, said valve doors being hinged for opening and closing by radially pivotal movement; (c) a plurality of radially movable actuation arms, each of said actuation arms being attached with one of said valve doors for opening and closing said valve doors; (d) control means for effecting radial movement of each of said actuation arms in response to preselected engine operating conditions; and (e) a plurality of resilient members disposed around said actuation arms for effecting radial movement of said actuation arm to open said valve doors in the event of predetermined conditions.

Claim 23

An air modulation apparatus according to claim 20 further including: first and second coaxially spaced shafts interconnecting said compressor and said turbine of said engine, said first shaft disposed radially outwardly of said second shaft and including a plurality of circumferentially spaced holes; and wherein said nozzle is effective for discharging cooling air from said outlets in a direction generally tangential to a direction of rotation of said first shaft and into said holes therein.