Passive boundary layer bleed system for nacelle inlet airflow control

Patent metadata

Field	Value
Publication number	US-9644535-B2
Application number	US-201414325583-A
Country	US
Kind code	B2
Filing date	Jul 8, 2014
Priority date	Oct 12, 2006
Publication date	May 9, 2017
Grant date	May 9, 2017

Abstract

A nacelle for a gas turbine engine system includes a housing that has a pressure side and a suction side. A passage extends between the pressure side and the suction side for permitting airflow from the pressure side to the suction side. The passage includes a first curved section that has an inlet at the pressure side. A linear section is connected with the first curved section. A second curved section is connected with the linear section and has an outlet at the suction side. The outlet has a cross sectional area smaller than a cross sectional area of the linear section.

First claim

We claim:

1. A nacelle for a gas turbine engine system, comprising:
a housing having a pressure side and a suction side, the pressure side is located radially outward from the suction side; and
a passage extending between the pressure side and the suction side for permitting airflow from the pressure side to the suction side and the passage includes a first curved section having an inlet at the pressure side, a linear section connected with the first curved section, and a second curved section connected with the linear section and having an outlet at the suction side, the outlet having a cross sectional area smaller than a cross sectional area of the linear section, wherein the passage is configured for passively drawing turbulent airflow into the nacelle.

2. The nacelle as recited in claim 1 , wherein the passage includes a section having a progressively increasing cross-sectional area.

3. The nacelle as recited in claim 2 , wherein the first curved section extends between a passage inlet at the pressure side and the linear section of the passage.

4. The nacelle as recited in claim 3 , wherein the first curved section includes a first cross-sectional area at the passage inlet and a second cross-sectional area at the linear section that is about 2.5 times greater than the first cross-sectional area.

5. The nacelle as recited in claim 1 , wherein the first curved section includes a progressively increasing cross-sectional area.

6. The nacelle as recited in claim 1 , wherein the housing includes an airflow surface and the passage includes the inlet that extends through the airflow surface, the airflow surface having a first section forward of the inlet relative to a direction of the airflow and a second section aft of the inlet, the first section defining a tangential plane wherein the second section is spaced apart from the tangential plane.

7. The nacelle as recited in claim 6 , wherein the second section is spaced an offset distance from the tangential plane depending on a thickness of an expected turbulent boundary layer.

8. The nacelle as recited in claim 6 , wherein the second section is spaced an offset distance of about 0.25 inches from the tangential plane.

9. The nacelle as recited in claim 6 , wherein the second section defines a scoop configured to direct airflow into the passage.

10. The nacelle as recited in claim 1 , wherein the housing includes an airflow surface having a transition section where airflow transitions from a first airflow that is generally laminar to a second airflow having a turbulent airflow component, wherein the passage extends from the airflow surface aft of the transition section.

11. A gas turbine engine system comprising:
a fan for air intake;
a nacelle that extends about the fan, the nacelle having a forward section that includes an outside airflow surface and an inside airflow surface relative to the fan; and
a passage located upstream of the fan extending between an inlet on the outside airflow surface and an outlet on the inside airflow surface, a first curved section extends from the inlet, a linear section connected with the first curved section, a second curved section connected with the linear section, the outlet includes a cross sectional area smaller than a cross sectional area of the linear section, wherein the passage is configured for passively drawing turbulent airflow into the nacelle.

12. The system as recited in claim 11 , wherein the passage is configured to permit airflow from the outside airflow surface toward the inside airflow surface and is configured for passively drawing turbulent airflow into the nacelle.

13. The system as recited in claim 11 , wherein the first curved section includes a progressively increasing cross-sectional area, the first curved section extends between the passage inlet at the outside airflow surface and the linear section of the passage.

14. The system as recited in claim 13 , wherein the first curved section includes a first cross-sectional area at the passage inlet and a second cross-sectional area at the linear section that is about 2.5 times greater than the first cross-sectional area.

15. The system as recited in claim 11 , wherein the passage includes the inlet that extends through the outside airflow surface, the outside airflow surface including a first section forward of the inlet relative to an airflow direction over the outside airflow surface and a second section aft of the inlet, the first section defining a tangential plane wherein the second section is spaced apart from the tangential plane.

16. A method of controlling a turbulent airflow over an airflow surface of a nacelle, comprising:
diverting at least a portion of the turbulent airflow from the airflow surface into a continuous passage located upstream of a fan, the passage includes a first curved section extending from an inlet, a linear section connected with the first curved section, and a second curved section connected with the linear section, and an outlet, wherein the passage extends between the inlet on a radially outer side of the nacelle and the outlet on a radially inner side of the nacelle, wherein the outlet has a cross sectional area smaller than a cross sectional area of the linear section.

17. The method as recited in claim 16 , further including producing a pressure differential between a passage inlet at the airflow surface and a passage outlet to urge the turbulent airflow into the passage.

18. The method as recited in claim 16 , further including diffusing the turbulent airflow to reduce a speed of the turbulent airflow within the passage.

Assignees

• United Technologies Corp

Inventors

• Zysman Steven H
• Lord Wesley K
• Miller Robert M
• Atassi Oliver V

Classifications

• F02C7/045

  having provisions for noise suppression · CPC title

• F02C7/04 Primary

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

• B64D2033/0226

  comprising boundary layer control means · CPC title

• F05D2250/71

  curved · CPC title

• Y10T137/0536

  Highspeed fluid intake means [e.g., jet engine intake] · CPC title