Ejector extension cooling for exhaust nozzle

• US 6,301,877 B1
• Filed: 11/13/1995
• Issued: 10/16/2001
• Est. Priority Date: 11/13/1995
• Status: Expired due to Term

• Current Assignee: United Technologies Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: United Technologies Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Yeager, William J., Soileau, John F., Liang, George P.
• Primary Examiner(s): KIM, TAE JUN
• Application Number:
  US08/556,317
• Time in Patent Office: 2,164 Days
• Field of Search: 602/261, 602/66, 602/62, 602/71, 60/390.7, 60/390.5, 60/398.3, 239/127.1, 239/127.3
• US Class Current: 60/226.1
• CPC Class Codes: F02K 1/822 Heat insulating structures or liners, cooling arrangements, e.g. post combustion liners; Infrared radiation suppressors
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

Abstract

The cooling of the exhaust nozzle of a fan jet engine powering aircraft is enhanced by providing an extension cooling concept that includes an extension piece extending axially downstream of the nozzles variable throat that utilizes fan air to cool the forward portion of the divergent nozzle surfaces adjacent to the gas path of the engine and ram air to cool the surfaces downstream of the ejector. A variable vane varies the area of the ejector slot as a function of Aj for compensating for flow losses at off-design points of the nozzle positions during the flight envelope of the aircraft so as to avoid overtemperature of the components.

Claims

1. For an exhaust nozzle for a gas turbine engine comprising at least a variable positioned convergent flap and a variable positioned divergent flap defining a variable geometry throat for directing the engine'"'"'s exhaust gases to discharge from the engine, the static pressure of said exhaust gases decreasing as it travels through the engine, a source of ram air and a source of fan air, means for cooling the convergent flap and the divergent flap including film cooling liner means and ejector means connecting the ram air to discharge in the exhaust gases, the improvement comprising a cooling extension downstream of said throat relative to the flow of exhaust gases having a first downstream axially extending wall, said first downstream axially extending wall having a film cooling liner adjacent to the exhaust gases, a second downstream axially extending wall radially spaced from said first downstream axially extending wall defining a first passage for leading fan air to said film cooling liner, a third downstream axially extending wall radially spaced from said second downstream axially extending wall for defining a second passage, said second passage forming a portion of said ejector means and being in fluid communication with the ram air and defining a discharge slot on the downstream end thereof, said discharge slot being axially spaced downstream of said throat and discharging the ram air from said ejector means into the exhaust gases, and the location of said discharge slot being selected to discharge the ram air into a low static pressure of the exhaust gases so that said low static pressure matches the pressure of the ram air discharging from said discharge slot.

2. For an exhaust nozzle for a gas turbine engine as claimed in claim 1 including a hinged connection connecting the convergent flap to the divergent flap at said throat.

3. For an exhaust nozzle for a gas turbine engine as claimed in claim 2 including a transition duct for leading engine exhaust gases to said convergent flap, additional hinge connection connecting said convergent flap to said transition duct.

4. For an exhaust nozzle for a gas turbine engine as claimed in claim 1 wherein said slot having a discharge edge and said edge being relatively straight and transversely disposed relative to the direction of flow of the exhaust gases.

5. For an exhaust nozzle for a gas turbine engine as claimed in claim 4 wherein said edge includes a single node extending parallel to the stream of the exhaust gases.

6. For an exhaust nozzle for a gas turbine engine as claimed in claim 5 wherein said edge includes a plurality of nodes extending in parallel to the stream of the exhaust gases.

7. For an exhaust nozzle for a gas turbine engine as claimed in claim 1 including vane means disposed adjacent to said slot for varying the area thereof, and means for actuating said vane means as a function of the geometry of the varying of the geometry of the throat.

8. A cooling system including an ejector and a cooling extension means for said ejector for cooling a two-dimensional vectoring exhaust nozzle for a gas turbine engine, said exhaust nozzle having opposing side walls and a convergent flap and a divergent flap defining a variable geometry throat for directing the engine'"'"'s exhaust gases to discharge from the engine adjacent said side opposing walls, a source of ram air and a source of fan air, said cooling extension having a downstream axially extending film cooling liner adjacent to the exhaust gases, a downstream axially extending wall radially spaced from said liner wall defining a first passage for leading fan air to said film cooling liner, a second downstream axially extending wall radially spaced from said first wall for defining a second passage, said second passage forming a portion of said ejector means and being in fluid communication with the ram air and defining a discharge slot on the downstream end thereof, said discharge slot being axially spaced downstream of said throat and discharging the ram air from said ejector means into the exhaust gases, and the location of the slot being selected to discharge the ram air into a low static pressure of the exhaust gases, said static pressure matching the pressure of the ram air discharging from said discharge slot, a hinged connection connecting the convergent flap to the divergent flap at said throat, a transition duct for leading engine exhaust gases to said convergent flap, additional hinge connection connecting said convergent flap to said transition duct.

9. A cooling system as claimed in claim 8 including vane means disposed adjacent to said slot for varying the area thereof, and means for actuating said vane means as a function of the geometry of the throat.

10. A cooling system as claimed in claim 9 including linkage means interconnecting said additional hinge means and being rotated therewith and said vane means.

11. A cooling system as claimed in claim 10 wherein said linkage means includes a vane support member and camming means for positioning said vane support member, said camming means includes a follower and an inclined cam slot for converting rectilinear movement to rotary movement.

12. A cooling system as claimed in claim 11 wherein said slot having a discharge edge and said edge being relatively straight and transversely disposed relative to the direction of flow of the exhaust gases.

13. A cooling system as claimed in claim 12 wherein said edge includes a single node extending parallel to the stream of the exhaust gases.

14. A cooling system as claimed in claim 13 wherein said edge includes a plurality of nodes extending parallel to the stream of the exhaust gases.