NACELLE INNER LIP SKIN WITH HEAT TRANSFER AUGMENTATION FEATURES

• US 20180194485A1
• Filed: 01/06/2017
• Published: 07/12/2018
• Est. Priority Date: 01/06/2017
• Status: Active Grant

• Current Assignee: ROHR Incorporated (Rtx Corporation)
• Original Assignee: ROHR Incorporated (Rtx Corporation)
• Inventors: Chilukuri, Radhakrishna
• Granted Patent: US 10,458,275 B2
• Time in Patent Office: Days
• CPC Class Codes: B64D 15/02 by ducted hot gas or liquid
• CPC Class Codes: B64D 15/04 Hot gas application
• CPC Class Codes: B64D 2033/0233 comprising de-icing means
• CPC Class Codes: B64D 33/02 of combustion air intakes air intakes for gas-turbine plants or jet-propulsion plants per se F02C7/04; air intakes for combustion engines in general F02M35/00
• CPC Class Codes: F01D 25/02 De-icing means for engines having icing phenomena
• CPC Class Codes: F01D 25/14 Casings modified therefor double casings F01D25/26
• CPC Class Codes: F02C 7/047 Heating to prevent icing
• CPC Class Codes: F05D 2220/323 for aircraft propulsion, e.g. jet engines
• CPC Class Codes: F05D 2260/2212 by creating turbulence
• CPC Class Codes: F05D 2260/2214 by increasing the heat transfer surface
• CPC Class Codes: F05D 2260/22141 using fins or ribs
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

Abstract

A nacelle inlet structure is provided for an aircraft propulsion system. This inlet structure includes an inlet lip, a bulkhead, a nozzle and a plurality of heat transfer augmentation features. The inlet lip includes an inner lip skin and an outer lip skin. The bulkhead is configured with the inlet lip to form a cavity axially between a forward end of the inlet lip and the bulkhead and radially between the inner lip skin and the outer lip skin. The annular cavity extends along a curvilinear centerline within the inlet lip. The nozzle is configured to inject fluid approximately tangentially into the annular cavity. The heat transfer augmentation features are configured with the inner lip skin and operable to interact with the fluid flow within the cavity in order to promote heat transfer between the inner lip skin and the fluid within the cavity.

Claims

1. A nacelle inlet structure for an aircraft propulsion system, comprising:

an inlet lip comprising an inner lip skin and an outer lip skin;

a bulkhead configured with the inlet lip to form a cavity axially between a forward end of the inlet lip and the bulkhead and radially between the inner lip skin and the outer lip skin, wherein the cavity extends along a longitudinal centerline within the inlet lip;

a nozzle configured to inject fluid approximately longitudinally into the cavity; and

a plurality of heat transfer augmentation features configured with the inner lip skin and operable to interact with the fluid within the cavity in order to promote heat transfer between the inner lip skin and the fluid within the cavity.

2. The nacelle inlet structure of claim 1, wherein the inlet skin comprises the heat transfer augmentation features.

3. The nacelle inlet structure of claim 1, wherein a first of the heat transfer augmentation features is milled into the inlet skin.

4. The nacelle inlet structure of claim 1, wherein a first of the heat transfer augmentation features comprises a groove.

5. The nacelle inlet structure of claim 1, wherein a first of the heat transfer augmentation features comprises a rib.

6. The nacelle inlet structure of claim 1, wherein

a first of the heat transfer augmentation features follows a helical first trajectory;

and

a second of the heat transfer augmentation features follows a helical second trajectory that is non-parallel to the helical first trajectory.

7. The nacelle inlet structure of claim 6, wherein the first of the heat transfer augmentation features and the second of the heat transfer augmentation features are substantially longitudinally aligned along the longitudinal centerline so as to collectively form an approximately chevron shaped feature.

8. The nacelle inlet structure of claim 1, wherein

a first of the heat transfer augmentation features follows a helical first trajectory;

and

a second of the heat transfer augmentation features follows a helical second trajectory that is approximately parallel to the helical first trajectory.

9. The nacelle inlet structure of claim 1, wherein a first of the heat transfer augmentation features follows a first trajectory that is non-parallel to the longitudinal centerline.

10. The nacelle inlet structure of claim 1, wherein a first of the heat transfer augmentation features follows a first trajectory that is substantially parallel to the longitudinal centerline.

11. The nacelle inlet structure of claim 1, wherein the cavity is formed radially between an outer side of the inner lip skin and an inner side of the outer lip skin, and the heat transfer augmentation features provide at least a portion of the outer side of the inner lip skin with a textured surface.

12. The nacelle inlet structure of claim 11, wherein substantially all of the inner side of the outer lip skin that forms the cavity is configured with a substantially smooth surface.

13. The nacelle inlet structure of claim 1, wherein the inner lip skin has a single layer thickness.

14. The nacelle inlet structure of claim 1, wherein the inner lip skin comprises metal.

15. A nacelle inlet structure for an aircraft propulsion system, comprising:

an inlet lip comprising an inner lip skin and an outer lip skin; and

a bulkhead configured with the inlet lip to form an annular cavity axially between a forward end of the inlet lip and the bulkhead and radially between an outer side of the inner lip skin and an inner side of the outer lip skin, wherein the cavity extends along an annular curvilinear centerline within the inlet lip;

wherein at least a portion of the outer side of the inner lip skin that forms the cavity comprises a relatively rough textured surface, and substantially all of the inner side of the outer lip skin that forms the cavity consists essentially of a substantially smooth surface.

16. The nacelle inlet structure of claim 15, wherein the relatively rough textured surface is axially next to the bulkhead.

17. The nacelle inlet structure of claim 15, wherein the relatively rough textured surface is formed by milling the inlet skin.

18. The nacelle inlet structure of claim 15, further comprising a nozzle configured to inject fluid into the annular cavity approximately tangential to the curvilinear centerline, wherein

the inner lip skin comprises a plurality of heat transfer augmentation features that form the relatively rough textured surface;

and

the heat transfer augmentation features are operable to contact the fluid within the cavity and thereby promote heat transfer between the inner lip skin and the fluid within the cavity.

19. A nacelle inlet structure for an aircraft propulsion system, comprising:

an inlet lip comprising an inner lip skin and an outer lip skin;

a bulkhead configured with the inlet lip to form an annular cavity axially between a forward end of the inlet lip and the bulkhead and radially between an outer side of the inner lip skin and an inner side of the outer lip skin, wherein the annular cavity extends along a curvilinear centerline within the inlet lip; and

a plurality of parallel ribs at the outer side of the inner lip skin.

20. The nacelle inlet structure of claim 19, further comprising;

a nozzle configured to inject fluid approximately tangentially into the annular cavity; and

a plurality of heat transfer augmentation features operable to interact with the fluid within the cavity and promote heat transfer between the inner lip skin and the fluid within the cavity;

wherein the heat transfer augmentation features comprise the parallel ribs.