Nacelle with porous surfaces

Patent metadata

Field	Value
Publication number	US-8974177-B2
Application number	US-89199110-A
Country	US
Kind code	B2
Filing date	Sep 28, 2010
Priority date	Sep 28, 2010
Publication date	Mar 10, 2015
Grant date	Mar 10, 2015

Abstract

A fan nacelle for a gas turbine engine includes a leading edge region with a flow path between an intake region in a nacelle outer surface and an exhaust region in a nacelle inner surface to locally modify a flow around the leading edge region during a predefined off-design condition.

First claim

What is claimed:

1. A fan nacelle for a gas turbine engine comprising:
an annular leading edge region that extends around an axis and defines a flow path between an intake region at a nacelle radially outermost surface and an exhaust region at a nacelle radially innermost surface, wherein said exhaust region includes a porous structure; and
a tertiary region within the innermost surface forward of the exhaust region, the tertiary region including a blind opening, the blind opening comprising a concave region formed in the nacelle radially innermost surface, straddling a shock line.

2. The fan nacelle as recited in claim 1 , wherein said intake region includes another porous structure.

3. The nacelle assembly as recited in claim 2 , wherein said porous structures include micro-pores.

4. The nacelle assembly as recited in claim 2 , wherein said porous structures include slot-like structures.

5. The fan nacelle as recited in claim 2 , wherein open areas of said porous structures are optimized to minimize losses at conditions other than a predefined off-design condition.

6. The fan nacelle as recited in claim 5 , wherein said conditions other than said predefined off-design condition includes a cruise condition.

7. The fan nacelle as recited in claim 2 , including an open flow path extending radially between the porous structures.

8. The fan nacelle as recited in claim 1 , wherein said intake region and said exhaust region extend for a circumferential distance around a nacelle keel of said leading edge region axially forward of a throat region.

9. The fan nacelle as recited in claim 1 , wherein said blind opening includes another porous structure.

10. The fan nacelle as recited in claim 1 , wherein an axially forward-most point of said intake region is axially forward of an axially forward-most point of said exhaust region.

11. The fan nacelle as recited in claim 10 , wherein an axially aft-most point of said intake region is axially forward of an axially aft-most point of said exhaust region.

12. The fan nacelle as recited in claim 1 , wherein said intake region is located at a position on a nacelle keel within a captured streamline at a predefined angle of attack such that a portion of said captured stream line enters said intake region.

13. A nacelle assembly for a gas turbine engine comprising:
a core nacelle defined about an engine centerline axis;
a fan nacelle defined about said engine centerline axis and mounted at least partially around said core nacelle to define a fan bypass flow path, said fan nacelle defines a leading edge region that defines a flow path between an intake region at a nacelle radially outermost surface and an exhaust region at a nacelle radially innermost surface; and
a tertiary region within the innermost surface forward of the exhaust region, the tertiary region including a blind opening, the blind opening comprising a concave region formed in the nacelle radially innermost surface, straddling a shock line.

14. The nacelle assembly as recited in claim 13 , wherein said intake region and said exhaust region extend for a circumferential distance around a nacelle keel of said leading edge region axially forward of a throat region.

15. The nacelle assembly as recited in claim 13 , wherein said intake region and said exhaust region each includes a porous structure.

16. The nacelle assembly as recited in claim 15 , including an open flow path extending radially between the porous structures.

17. The nacelle assembly as recited in claim 13 , wherein said porous structure includes micro-pores.

18. The nacelle assembly as recited in claim 13 , wherein said tertiary region includes a porous structure.

19. The nacelle assembly as recited in claim 18 , wherein said porous structure includes micro-pores.

20. A method to locally modify a flow around a leading edge region of a nacelle to move a captured streamline stagnation region forward and weaken a shock strength comprising:
communicating a portion of a captured streamline through a flow path defined between an intake region in a nacelle outermost surface and an exhaust region in a nacelle innermost surface during a predefined off-design condition, wherein said exhaust region includes a porous structure; and
locating a tertiary region within the innermost surface forward of the exhaust region to straddle a shock line.

21. A method as recited in claim 20 , further comprising:
optimizing an open area of a porous structure within the intake region and the exhaust region to minimize losses at conditions other than the predefined off-design condition.

22. A method as recited in claim 20 , further comprising:
optimizing the flow path to minimize losses at conditions other than the predefined off-design condition.

23. A method as recited in claim 20 , further comprising:
defining the predefined off-design condition as a high-angle of attack condition.

24. A method as recited in claim 20 , said tertiary region including a blind opening, and said blind opening is configured to axially span a shock such that suction occurs downstream of the shock and blowing occurs upstream of the shock.

Assignees

• Atassi Oliver V
• United Technologies Corp

Inventors

• Atassi Oliver V

Classifications

• F02C7/04

  Air intakes for gas-turbine plants or jet-propulsion plants · CPC title

• F02K3/06 Primary

  with front fan · CPC title

• B64D33/02

  of combustion air intakes · CPC title

• Y10S415/914

  Device to control boundary layer · CPC title

• F05D2300/514

  Porosity · CPC title