AFT exhaust system for rotary wing aircraft

Patent metadata

Field	Value
Publication number	US-10562641-B2
Application number	US-201314049735-A
Country	US
Kind code	B2
Filing date	Oct 9, 2013
Priority date	Oct 10, 2012
Publication date	Feb 18, 2020
Grant date	Feb 18, 2020

Abstract

An exhaust system for reducing infrared emissions of a rotary wing aircraft includes a duct assembly having an inlet portion and an outlet portion; the inlet portion configured to receive exhaust from an engine of the aircraft; and the outlet portion coupled to the inlet portion, the outlet portion having an outlet duct with an outlet opening, the outlet duct configured expel an emission containing engine exhaust proximate to a tail fairing of the rotary wing aircraft.

First claim

The invention claimed is:

1. An exhaust system for reducing infrared emissions of a rotary wing aircraft, the exhaust system comprising:
a duct assembly having an inlet portion and an outlet portion, the duct assembly being positioned within a chamber of an airframe;
the inlet portion being configured to receive exhaust from an engine of the aircraft, wherein a cross-section of the inlet portion varies in an aft direction;
the outlet portion being coupled to the inlet portion, the outlet portion having an outlet duct with an outlet opening disposed at an aft end of the outlet duct, opposite the inlet portion, the outlet opening being configured to expel an emission containing engine exhaust proximate to a tail fairing an aft end of the rotary wing aircraft on both sides of a thrust axis of a translational thrust system of the rotary wing aircraft; and
a plurality of openings distinct from the inlet opening and the outlet opening formed in at least one of the inlet portion and the outlet portion of the duct assembly, wherein air provided to an interior of the duct via the plurality of openings such that the air is entrained with the exhaust within an interior of the duct assembly.

2. The exhaust system of claim 1 wherein the outlet duct is configured for placement proximate to horizontal stabilizer of the tail faring of the rotary wing aircraft.

3. The exhaust system of claim 1 wherein the inlet portion includes an inlet duct configured to couple to an opening in a firewall to receive the engine exhaust.

4. The exhaust system of claim 1 wherein the outlet portion includes two outlet ducts.

5. The exhaust system of claim 4 wherein the two outlet ducts are embedded in a horizontal stabilizer of the tail fairing.

6. The exhaust system of claim 4 wherein the two outlet ducts are positioned on opposite sides of a thrust axis of the translational thrust system.

7. The exhaust system of claim 6 wherein the translational thrust system is a propeller, the two outlet ducts positioned on opposite sides of a rotational axis of the propeller.

8. The exhaust system of claim 1 wherein the outlet duct is aligned with a thrust axis of the translational thrust system of the rotary wing aircraft.

9. The exhaust system of claim 1 wherein the outlet duct is centered with a thrust axis of the translational thrust system of the rotary wing aircraft.

10. The exhaust system of claim 1 wherein the inlet portion is circular and the outlet portion is rectangular.

11. The exhaust system of claim 1 wherein the inlet portion is circular and the outlet portion is circular.

12. A rotary wing aircraft comprising:
a rotor having a plurality of rotor blades;
an engine for driving the rotor;
a frame supporting a tail fairing;
an exhaust system for reducing infrared emissions of the rotary wing aircraft, the exhaust system including:
a duct assembly having an inlet portion and an outlet portion, the duct assembly being positioned within a chamber of an airframe; the inlet portion including an inlet opening configured to receive exhaust the engine, wherein a cross-section of the inlet portion varies in an aft direction;
the outlet portion coupled to the inlet portion, the outlet portion having an outlet duct with an outlet opening disposed at an aft end of the outlet duct, opposite the inlet portion, the outlet opening being configured to expel an emission including the engine exhaust proximate to an aft end of the rotary wing aircraft on both sides of a thrust axis of a translational thrust system of the rotary wing aircraft; and
a plurality of openings distinct from the inlet opening and the outlet opening is formed in at least one of the inlet portion and the outlet portion of the duct assembly, wherein aft provided to an interior of the duct via the plurality of openings such that the air is entrained with the exhaust within an interior of the engine within the duct assembly.

13. The rotary wing aircraft of claim 12 further comprising: a horizontal stabilizer at the tail faring;
wherein the outlet portion includes two outlet ducts, wherein the two outlet ducts are embedded in the horizontal stabilizer and the two outlet ducts are positioned on opposite sides of a thrust axis at the translational thrust system.

14. The rotary wing aircraft of 13 wherein the translational thrust system is a propeller, the two outlet ducts positioned on opposite sides of a rotational axis of the propeller.

15. The rotary wing aircraft of claim 12 wherein the inlet portion is circular and the outlet portion is rectangular.

Assignees

• Sikorsky Aircraft Corp

Inventors

• Pantalone Iii Joseph
• Devito Ashley
• Chapkovich Iii John S
• Weiner Steven D

Classifications

• B64D2033/045

  comprising infrared suppressors · CPC title

• F02K1/825

  Infrared radiation suppressors · CPC title

• F02K3/072

  with counter-rotating {, e.g. fan} rotors · CPC title

• B64C2027/8236

  including pusher propellers · CPC title

• B64D33/04 Primary

  of exhaust outlets or jet pipes · CPC title