METHODS AND APPARATUSES FOR CONTROLLING AIRFLOW PROXIMATE TO ENGINE/AIRFOIL SYSTEMS
Methods and apparatuses for controlling airflow proximate to engine/airfoil systems are disclosed. In one embodiment, an aircraft system includes an airfoil and an engine unit at least proximate to the airfoil with a gap between a portion of the airfoil and a portion of the engine unit. The system can further include a flow control device proximate to the gap and positionable among at least three stationary positions, including a retracted position in which the gap has a first area through which fluid can flow, a first extended position in which the gap is at least approximately aerodynamically sealed, and a second extended position in which the gap has a second smaller area through which fluid can flow. A control system can be coupled to the flow control device to move the flow control device among these positions.
Embodiments of the present invention relate to methods and apparatuses for controlling airflow proximate to engine/airfoil systems, for example, on aircraft with wing-mounted engine units.
BACKGROUNDMany modern-day aircraft include leading edge high lift devices (e.g., slats and Krueger flaps) to improve performance during certain phases of flight (e.g., takeoff and landing). Many of these aircraft also have wing-mounted propulsion units that are carried under the wing of the aircraft. The wing-mounted propulsion units can interfere with flow over the wing and detract from aircraft performance.
The local flow pattern around and through the gap 5 can be quite complex, especially when the aircraft is operated at higher angles of attack and/or when the high lift leading edge devices 12a, 12b are deployed. The interface between the wing 10 and propulsion unit 20, including the gap 5, is often optimized for the cruise condition when the high lift leading edge devices 12a, 12b are stowed. As angle of attack is increased above cruise values, the air flow through the gap 5 can often cause the performance (e.g., local drag coefficient and/or local lift coefficient) of the local wing section proximate to the gap 5 to degrade as compared to similar wing sections located away from the gap 5. Additionally, because the propulsion unit 20 interferes with the installation and/or deployment of high lift leading edge devices, the high lift leading edge devices 12a, 12b often do not extend laterally across the wing 10 in the area where the gap 5 is located. Accordingly, the local wing section proximate to the gap 5 does not get the performance benefits provided by the high lift leading edge devices 12a, 12b. Even if the high lift leading edge devices 12a, 12b extend laterally across the gap 5, the flow interference created by the wing 10 and the propulsion unit 20 can reduce the performance of the local wing section proximate to the gap 5.
One approach to addressing this problem is to provide the aircraft with a small flap-type device 30 that seals the gap when the high lift devices 12a, 12b are deployed. In
The present invention is directed generally toward methods and apparatuses for controlling airflow proximate to engine unit/airfoil systems. One aspect of the invention is directed toward an aircraft system having an airfoil and an engine unit. The engine unit can be at least proximate to the airfoil with a gap between a portion of the airfoil and a portion of the engine unit. The system can further include a flow control device proximate to the gap and positionable among at least three stationary positions. The three stationary positions can include a retracted position in which the gap has a first area through which fluid can flow, a first extended position in which the gap is at least approximately aerodynamically sealed, and a second extended position in which the gap has a second area through which fluid can flow. The second area can be smaller than the first area. In further aspects of the invention, the aircraft system can include a flow control device having multiple flow surface sections movable relative to each other.
Another aspect of the invention is directed toward a method for making an aircraft system that includes installing a flow control device at least proximate to an airfoil and an engine unit. The method can further include coupling a control system (e.g., an actuator and/or a computer) to the flow control device and configuring the control system to position the flow control device among at least three stationary positions. The three stationary positions can include a retracted position in which a gap between a portion of the airfoil and a portion of the engine unit has a first area through which fluid can flow, a first extended position in which the gap is at least approximately aerodynamically sealed, and a second extended position in which the gap has a second area through which fluid can flow, with the second area being smaller than the first area.
BRIEF DESCRIPTION OF THE DRAWINGS
The present disclosure describes methods and apparatuses for controlling airflow proximate to engine/airfoil systems, for example, on aircraft having wing-mounted engine units. Several specific details of the invention are set forth in the following description and in
The flow control device 230 can be coupled to the airfoil 210 and can be positioned proximate to the gap 205. The flow control device 230 can include multiple flow surface sections (shown in
In
During other operating conditions (e.g., cruise conditions), the flow control device 230 can be positioned in the retracted position (shown by the dashed lines in
The dotted lines show the flow control device 230 in a second extended position that can provide selected performance characteristics (e.g., an increase in maximum lift coefficient) during other operating conditions and/or phase(s) of flights (e.g., landing). In the second extended position, the flow control device 230 is positioned to provide a second area through which fluid can flow, with the second area smaller than the first area associated with the retracted position described above. For example, the flow control device 230 can be placed in the first extended position, discussed above, and the second portion 230b of the flow control device 230 can be pivoted upwardly from the housing 222 to allow fluid flow through a portion of the gap 205. Accordingly, as fluid approaches the gap 205, a portion of the fluid can pass through the gap (shown by arrow F2) and a portion of the fluid can be forced generally up and over the airfoil 210 (shown by arrow F1). The fluid flow proximate to the gap 205 can provide a fluid flow pattern, different from those associated with the retracted and first extended positions, that provides a distinct set of desired performance characteristics at selected operating conditions and/or phase(s) of flight. For example, the second extended position can provide a flow pattern that increases the maximum lift coefficient of a section of the airfoil 210 proximate to the gap 205 during the landing phase of flight.
The aircraft system 200 shown in
The first actuator 241a can include a hydraulic actuator coupled between the airfoil 210 and the first section 230a of the flow control device 230 and can be configured to move the flow control device 230 between the retracted and the first extended position. The second actuator 241b can include an electric actuator and can be coupled between the first and second sections 230a, 230b of the flow control device 230 to move the flow control device 230 between the first extended position and the second extended position. For example, the second actuator 241b can move the flow control device 230 between the first extended position and the second extended position by moving the second section 230b of the flow control device 230, while the first section 230a of the flow control device 230 is held stationary by the first actuator 241a. In certain embodiments, the first and second actuators 241a, 241b can operate simultaneously, for example, to move the flow control device 230 between the retracted and the first extended positions. In other embodiments, the first and second actuators 241a, 241b can operate sequentially.
The computer 245 can be connected to the first and second actuators 241a, 241b by the signal paths 243 and can be programmed to control the movement of the flow control device 230 among the retracted, first extended, and second extended positions. In other embodiments, more or fewer actuators 241 can be used to position the flow control device 230, and/or the actuators 241 can be connected to the flow control device 230 in other arrangements (e.g., connected to different sections of the flow control device 230). In still other embodiments, the control system 240 can have different kinds of elements and/or can transmit different kinds of signals. For example, in certain embodiments the control system 240 can be a purely mechanical system, a purely electrical system, a hydraulic system, or any combination thereof. In other embodiments, the signal paths 243 can include fiber optic pathways. In yet other embodiments of the invention, the control system 240 can direct the flow control device 230 to move to more than three stationary positions, providing aircraft designers with an increased capability to tailor fluid flow patterns proximate to the gap 205 for a variety of different operating conditions.
In certain embodiments, the engine unit 220 can include a thrust reverser 225. At least a portion of the engine housing 222 can be coupled to the thrust reverser and can be configured to move aft when the thrust reverser is deployed, as shown by arrows T in
In further embodiments of the invention, the airfoil 210 and the engine unit 220 can include other arrangements and/or components, and the gap 205 can be formed between other portions of the airfoil 210 and the engine unit 220. For example, in certain embodiments the engine unit 220 is not directly coupled to the airfoil 210 (e.g., the engine unit 220 can be located proximate to the airfoil 210, but coupled to a fuselage of the aircraft) and/or the engine unit 220 does not extend in front of the leading edge 211 of the airfoil 210. Additionally, in some embodiments additional structural elements associated with the airfoil 210, the engine unit 220, a portion of the flow control device 230 (even when in the retracted position), and/or other aircraft components can protrude into the gap 205, even when the flow control device 230 is in the retracted position. For example, in certain embodiments the pylon 221 can be located behind the gap 205. In still other embodiments, the airfoil 210 and engine unit 220 can define multiple gaps 205 (e.g., multiple gaps of varying widths located side by side or separated by aircraft components) and/or the system can include multiple flow control devices 230. For example, a gap 205 and a flow control device 230 can be located outboard of the pylon 221.
A feature of foregoing embodiments described above with reference to
In other embodiments, the flow control devices can include other types of control surfaces. For example,
In other embodiments, the flow control device can be coupled to aircraft components other than the airfoil. For example,
The flow control device 630 can be positionable among at least three stationary positions, including a retracted position, a first extended position, and a second extended position. In the retracted position, the upper and lower sections 630a, 630b of the flow control device 630 can be rotated aft and positioned proximate to the pylon 621 so that the gap 605 has a first area through which fluid can flow. In the first extended position, the lower and upper sections 630a, 630b of the flow control device 630 can be rotated forward and positioned to at least approximately aerodynamically seal the gap 605. In the second extended position, the upper section 630a of the flow control device 630 can be rotated forward and the lower section 630b can be rotated aft and positioned proximate to the pylon 621 (similar to being in the retracted position) so that the gap 605 can have a second area, smaller than the first area, through which fluid can flow. The flow control device 630 can control the airflow proximate to the gap 605 to provide selected performance characteristics, as discussed above with reference to
In other embodiments, in the second extended position the upper section 630a of the flow control device 630 can be rotated aft and the lower section 630b can be rotated forward. In still other embodiments, the flow control device 630 can include more or fewer sections and/or other arrangements (e.g., the upper and lower sections 630a, 630b can slide laterally into and out of the pylon 621). In certain embodiments, one or both of the upper and lower sections 630a, 630b of the flow control device 630 can also seal against a lateral edge of a leading edge device as discussed above with reference to
The flow control device 730 can be positionable among at least three stationary positions, including a retracted position, a first extended position, and a second extended position. In the retracted position, the main and vent sections 730a, 730b of the flow control device 730 can be rotated down about point B, as shown by arrow D, and positioned proximate to the housing 722 of the engine unit 720 so that the gap 705 has a first area through which fluid can flow. In the first extended position, the main and vent sections 730a, 730b of the flow control device 730 can be rotated up about point B and positioned so that the main section 730a can be at least approximately aerodynamically sealed against the airfoil 710. Additionally, the vent section 730b can be placed in the sealed position so that the flow control device 730 at least approximately aerodynamically seals the gap 705. In the second extended position, the main section 730a can be at least approximately aerodynamically sealed against the airfoil 710 and the vent section 730b can be placed in the open position, opening the vent area so that the gap 705 can have a second area, smaller than the first area, through which fluid can flow. The flow control device 730 can control the airflow proximate to the gap 705 to provide selected performance characteristics, as discussed above with reference to
In other embodiments, the vent area or slot created by the vent section 730b of the flow control device 730 can be located in other parts of the main section 730a of the flow control device 730 (e.g., closer to the airfoil 710). In still other embodiments, the flow control device 730 can have more or fewer sections and/or different types of sections. For example, in other embodiments, the flow control device 730 can include a single section with multiple positions or a flap-type device with hinged segments.
A feature of foregoing embodiments discussed above with reference to
From the foregoing, it will be appreciated that specific embodiments of the invention have been described herein for purposes of illustration, but that various modifications may be made without deviating from the spirit and scope of the invention. Additionally, features described in the context of particular embodiments can be combined or eliminated in other embodiments. For example, in another embodiment, a flow control device can include a first section that depends from an airfoil, similar to embodiments discussed with reference to
Claims
1. An aircraft system comprising:
- an airfoil;
- an engine unit having a housing at least proximate to the airfoil with a gap extending between a portion of the airfoil and a portion of the housing of the engine unit; and
- a flow control device proximate to the gap and positionable among at least three stationary positions, including: a retracted position in which the gap has a first area through which fluid flows during flight, a first extended position in which the gap is at least approximately aerodynamically sealed during flight; and a second extended position in which the gap has a second area through which fluid flows during flight, the second area being smaller than the first area.
2. The system of claim 1 wherein the flow control device includes multiple flow surface sections movable relative to each other.
3. The system of claim 1 wherein the engine unit includes a pylon, the engine unit being coupled to the airfoil via the pylon, the engine unit being positioned under the airfoil with a portion of the engine unit extending forward of a leading edge of the airfoil.
4. The system of claim 1 wherein the flow control device is coupled to the airfoil.
5. The system of claim 1 wherein the engine unit includes a pylon and the flow control device is coupled to the pylon.
6. The system of claim 1 wherein the flow control device is coupled to the housing.
7. The system of claim 1 wherein the engine unit includes a thrust reverser, at least a portion of the engine housing being coupled to the thrust reverser to move when the thrust reverser is deployed, and wherein at least a portion of the flow control device moves with the engine housing when the flow control device is in the first extended position.
8. The system of claim 1, further comprising a control system coupled to the flow control device to position the flow control device among the retracted, first extended, and second extended positions.
9. The system of claim 1, further comprising a control system coupled to the flow control device to position the flow control device among the retracted, first extended, and second extended positions, the control system having at least one actuator, the at least one actuator including at least one hydraulic actuator.
10. The system of claim 1, further comprising a control system coupled to the flow control device to position the flow control device among the retracted, first extended, and second extended positions, the control system having at least one actuator, the at least one actuator including at least one electric actuator.
11. The system of claim 1, further comprising a control system coupled to the flow control device to position the flow control device among the retracted, first extended, and second extended positions, at least a portion of the control system including a computer.
12. The system of claim 1, further comprising a control system coupled to the flow control device to position the flow control device among the retracted, first extended, and second extended positions, the control system including:
- a first actuator coupled to the flow control device to position the flow control device between the retracted and first extended positions; and
- a second actuator coupled to the flow control device to position the flow control device between the first and second extended positions.
13. The system of claim 1, further comprising a control system coupled to the flow control device to position the flow control device among the retracted, first extended, and second extended positions, wherein the flow control device includes a first portion and a second portion and wherein only the second portion of the flow control device moves when the flow control device is positioned between the first extended position and the second extended position.
14. The system of claim 1 wherein the airfoil includes at least one leading edge device laterally disposed from the flow control device and wherein the flow control device is at least approximately aerodynamically sealed against a portion of a lateral edge of the leading edge device when the flow control device is in at least one of the first and second extended positions.
15. The system of claim 1 wherein the engine unit includes a pylon and wherein the flow control device is at least approximately aerodynamically sealed against at least a portion of the pylon.
16. The system of claim 1 wherein the engine unit includes a pylon, the engine unit being coupled to the airfoil via the pylon, the engine unit being positioned under the airfoil with a portion of the engine unit extending forward of the leading edge of the airfoil, a portion of the pylon being positioned behind the gap.
17. The system of claim 1 wherein the airfoil, engine unit, and flow control device are installed on an aircraft.
18. The system of claim 1 wherein the flow control device includes a Krueger flap.
19. The system of claim 1 wherein the flow control device includes a slat.
20. The system of claim 1 wherein the flow control device includes a variable camber leading edge device.
21. The system of claim 1, further comprising a control system coupled to the flow control device to position the flow control device among the retracted, first extended, and second extended positions, the control system including:
- a first actuator coupled to the flow control device to position the flow control device between the retracted and first extended positions; and
- a second actuator coupled to the flow control device to position the flow control device between the first and second extended positions; and wherein:
- the engine unit includes a pylon, the engine unit being coupled to the airfoil via the pylon, the engine unit being positioned under the airfoil with a portion of the engine unit extending forward of a leading edge of the airfoil; and
- the flow control device depends from the airfoil and includes multiple flow surface sections movable relative to each other.
22. An aircraft system comprising:
- an airfoil;
- an engine unit at least proximate to the airfoil, the engine unit including a pylon and a housing, the engine unit being coupled to the airfoil via the pylon, the engine unit being positioned under the airfoil with a portion of the engine unit extending forward of a leading edge of the airfoil, a gap extending between a portion of the housing and a portion of the leading edge of the airfoil;
- a flow control device coupled to the airfoil and having multiple flow surface sections movable relative to each other, the flow control device being positionable among at least three stationary positions, including: a retracted position in which the gap has a first area through which fluid can flow; a first extended position in which the gap is at least approximately aerodynamically sealed; and a second extended position in which the gap has a second area through which fluid can flow, the second area being smaller than the first area; and
- a control system coupled to the flow control device to position the flow control device among the retracted, first extended, and second extended positions, the control system including: a first actuator coupled to the flow control device to position the flow control device between the retracted and first extended positions; and a second actuator coupled to the flow control device to position the flow control device between the first and second extended positions.
23. The system of claim 22 wherein the airfoil, engine unit, and flow control device are installed on an aircraft.
24. An aircraft system comprising:
- an airfoil;
- an engine unit at least proximate to the airfoil with a gap between a portion of the airfoil and a portion of the engine unit; and
- a flow control means for controlling the flow of fluid through the gap, the flow control means having at least three stationary positions, including: a retracted position in which the gap has a first area through which fluid can flow; a first extended position in which the gap is at least approximately aerodynamically sealed; and a second extended position in which the gap has a second area through which fluid can flow, the second area being smaller than the first area.
25. The system of claim 24 wherein the airfoil, engine unit, and flow control means are installed on an aircraft.
26. A method for making an aircraft system comprising:
- installing a flow control device at least proximate to an airfoil and an engine unit having a housing;
- coupling a control system to the flow control device; and
- configuring the control system to position the flow control device among at least three stationary positions, including: a retracted position in which a gap extending between a portion of the airfoil and a portion of the housing of the engine unit has a first area through which fluid flows during flight; a first extended position in which the gap is at least approximately aerodynamically sealed during flight; and a second extended position in which the gap has a second area through which fluid flows during flight, the second area being smaller than the first area.
27. The method of claim 26 wherein installing a flow control device includes installing a flow control device having multiple flow surface sections that are movable relative to each other.
28. The method of claim 26 wherein installing a flow control device at least proximate to an airfoil and an engine unit includes installing a flow control device proximate to an airfoil and an engine unit on an aircraft, the engine unit having a pylon, the engine unit being coupled to the airfoil via the pylon, the engine unit being positioned under the airfoil with a portion of the engine unit extending forward of a leading edge of the airfoil.
29. The method of claim 26 wherein installing a flow control device includes coupling a flow control device to the airfoil.
30. The method of claim 26 wherein installing a flow control device includes coupling a flow control device to a portion of the engine unit.
31. The method of claim 26 wherein configuring a control system includes configuring a computer.
32. The method of claim 26 wherein configuring the control system to position the flow control device includes configuring the control system to position the flow control device in the second extended position to increase at least one of a maximum lift coefficient or a lift to drag ratio of a portion of the airfoil.
33. The method of claim 26 wherein configuring the control system to position the flow control device includes configuring the control system to position the flow control device in the first extended position to increase at least one of a maximum lift coefficient or a lift to drag ratio of a portion of the airfoil.
34. The method of claim 26 wherein configuring the control system to position the flow control device includes configuring the control system to position the flow control device in the first extended position to decrease the drag coefficient of a portion of the airfoil.
35. The method of claim 26 wherein configuring the control system to position the flow control device includes configuring the control system to position the flow control device in the second extended position to decrease the drag coefficient of a portion of the airfoil.
36. The method of claim 26 wherein installing a flow control device at least proximate to an airfoil and an engine unit includes coupling a flow control device to an airfoil on an aircraft, the flow control device having multiple flow surface sections that are movable relative to each other, the engine unit having a pylon, the engine unit being coupled to the airfoil via the pylon, the engine unit being positioned under the airfoil with a portion of the engine unit extending forward of a leading edge of the airfoil.
37. A method for operating an aircraft comprising:
- positioning a flow control device of the aircraft in a first extended position in which a gap extending between a portion of an airfoil and a portion of a housing of an engine unit is at least approximately aerodynamically sealed during flight;
- flying the aircraft with the flow control device in the first extended position;
- positioning the flow control device of the aircraft in a retracted position in which the gap has a first area through which air flows during flight;
- flying the aircraft with the flow control device in the retracted position;
- positioning the flow control device of the aircraft in a second extended position in which the gap has a second area through which air flows during flight, the second area being smaller than the first area; and
- flying the aircraft with the flow control device in the second extended position.
38. The method of claim 37 wherein flying the aircraft with the flow control device in the retracted position includes flying the aircraft during a cruise phase of flight with the flow control device in the retracted position.
39. The method of claim 37 wherein flying the aircraft with the flow control device in the first extended position includes flying the aircraft during a takeoff phase of flight with the flow control device in the first extended position.
40. The method of claim 37 wherein flying the aircraft with the flow control device in the second extended position includes flying the aircraft during a landing phase of flight with the flow control device in the second extended position.
Type: Application
Filed: Jun 15, 2004
Publication Date: Dec 15, 2005
Inventor: Roy Dun (Seattle, WA)
Application Number: 10/868,238