CA1105915A - Counter-rotating vortices generator for an aircraft wing - Google Patents
Counter-rotating vortices generator for an aircraft wingInfo
- Publication number
- CA1105915A CA1105915A CA306,774A CA306774A CA1105915A CA 1105915 A CA1105915 A CA 1105915A CA 306774 A CA306774 A CA 306774A CA 1105915 A CA1105915 A CA 1105915A
- Authority
- CA
- Canada
- Prior art keywords
- wing
- finger
- lift device
- fingers
- vortices
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 230000000694 effects Effects 0.000 claims abstract description 9
- 239000012530 fluid Substances 0.000 claims description 8
- 230000002708 enhancing effect Effects 0.000 abstract 1
- 230000033001 locomotion Effects 0.000 description 6
- 230000001276 controlling effect Effects 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64C—AEROPLANES; HELICOPTERS
- B64C23/00—Influencing air flow over aircraft surfaces, not otherwise provided for
- B64C23/06—Influencing air flow over aircraft surfaces, not otherwise provided for by generating vortices
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T50/00—Aeronautics or air transport
- Y02T50/10—Drag reduction
Landscapes
- Engineering & Computer Science (AREA)
- Aviation & Aerospace Engineering (AREA)
- Aerodynamic Tests, Hydrodynamic Tests, Wind Tunnels, And Water Tanks (AREA)
- Toys (AREA)
- Turbine Rotor Nozzle Sealing (AREA)
- Structures Of Non-Positive Displacement Pumps (AREA)
Abstract
COUNTER-ROTATING VORTICES GENERATOR FOR AN AIRCRAFT WING
ABSTRACT OF THE DISCLOSURE
A device for enhancing the lift capability of an aircraft wing is characterized by at least one forwardly projecting finger member mounted on the leading edge of the wing. The finger generates counter-rotating vortices, each in contact with the other, trailing backwardly across substantially the entire upper surface of the wing behind the fingers as the airflow moves upwardly and around the lateral edges of the finger. As the counter-rotating vortices trail backwardly over the upper surface of the wing, a blockage effect is created and the airflow patterns across the wing are modified to produce an increase in lift.
ABSTRACT OF THE DISCLOSURE
A device for enhancing the lift capability of an aircraft wing is characterized by at least one forwardly projecting finger member mounted on the leading edge of the wing. The finger generates counter-rotating vortices, each in contact with the other, trailing backwardly across substantially the entire upper surface of the wing behind the fingers as the airflow moves upwardly and around the lateral edges of the finger. As the counter-rotating vortices trail backwardly over the upper surface of the wing, a blockage effect is created and the airflow patterns across the wing are modified to produce an increase in lift.
Description
~1~5~5 COUNTER-ROTATING VORTICES GENERATOR FOR AN AIRCRAFT WING
BACKGROUND OF THE INVENTION
Field of the Invention This invention relates to a wing lift device for increasing the lift capability of aircraft wings.
Description of the Prior Art Lift of an airplane wing is a function of its forward speed and angle of attack. For each type of wing there is an upper limit to the angle of attack that can be effectively reached, beyond which a stall suddenly occurs with almost total loss of lift. The separation of the boundary layer from the surface of the aircraft wing occurs at a point on the surface of the wing at increasingly forward points from the trailing edge thereof as the angle of attack is increased. Therefore, in order to accommodate larger and heavier aircraft, it is necessary that progressively higher takeoff and landing velocities be maintained in order to prevent stall of the wing and the loss of lift cap-ability. It would be advantageous, therefore, to increase the lift capability of aircraft wings by more efficiently utilizing the airflow across the top surface of the wing.
SUMMARY OF THE INVENTION
The invention in its broader aspect pertains to apparatus for increasing the lift generated by an aircraft wing, having upper and lower surfaces, while propelled through a fluid medium. The apparatus comprises a finger mounted adjacent to the leading edge of the wing and extending forwardly therefrom such that the finger is essentially tangential to the upper surface of the wing, the finger having lateral edges thereon.
C
The finger is mounted on the wing such that as the wing is propelled through the fluid medium impingement of the fluid medium on the finger produces, by flow around the lateral edges, a first and second vortex trailing rearwardly from the finger over the upper surface of the wing in the direction of fluid flow, each of the vortices being in contact with and counter-rotating with respect to the other. The finger is sized such that each vortex produced thereby is of sufficient size and strength to modify the flow pattern above the boundary layer on the wing upper surface so as to effect an increase in the lift.
More particularly, the invention relates to, in combination to an aircraft wing, a wing lift device including at least one, but preferably a plurality of laterally spaced, for-wardly extending finger members mounted adjacent to the forward edge of the airfoil. The fingers may be mounted directly on the airfoil or supported a predetermined distance thereabove by suit-able struts or the like. The forwardly extending fingers obstruct the airflow impinging thereon at predetermined angles of attack so as to generate counter-rotating vortices trailing backwardly therefrom over substantially the entire upper surface of the wing that lies behind the fingers as the airflow moves upwardly -la-C
and over the lateral edges of thc fingcrs. Thc rin~ers ~re sized and configured such that the counter-rotating vorticcs produced thereby are in contact one with the other and remain intact as vortices as they extend backwardly and trail over the upper surface of the aircraft wing. As a result of the counter-rotating vortices, a blockage effect is created which modifies the airflow patterns across the upper surface of the wing and to produce increased lift capability o~ tl-e Will'1~
BRIEF DESCRIPTION OF TIIE DR~WINGS
The invention will be more fully understood from the following detailed description of a preferred embodiment thereof, taken in connection with the accompanying drawings, which form a part of the specification, and in which:
Figure 1 is a plan view of an aircraft wing illustrating a wing lift device embodyinq the teachings of this invention;
Figure 2 is a front view taken along lines 2 - 2 of Figure l;
Figure 3 is a section view of the wing of Fiyure l;
Figure 4 is an isolated perspective view of one embodiment of a wing lift device in accordance with the teachings of the invention;
Figure 5 is a fragmentary view of an alternate mode of attachment of the wincr lift device to an aircraft wing;
Figures 6, 7, 8, 9, 10, 11 and 12 are alternate embodiments of the invention.
_ESCRIPTION OF THF PREFERRED EMBODIMENT
Throughout the following description, similar reference numerals refer to similar elements in all figures of the drawings.
Referring to Figures 1 through 3, an aircraft wing, generally indicated by reference numeral 10, of known airfoil configuration as viewed in the cross section of Figure 3 is ~, ~
shown in isolation from the remainder oE the aircraft fusclagc and like structures with which it is normally associated. It is understood that the wing 10 may be either a conventional straight wing or a swept-back wing and still be utilizable in connection with a wing lift device generally indicated by reference numeral 12 embodying the teachings of this invention.
The wing 10 includes a forward or leading edge 14 and a rearward or trailing edge 16. An upper surface 18 and a lower surface 20 are interposed to connect the forward and rearward edges 14 and 16, respectively. The width C of the wing 10 is the distance between the leading edge 14 and trailing edge 16 of the wing 10. For definitional purposes, the wing 10 will be assumed to be confronted by an airflow indicated by a vector 22 approaching the leading edge 14 of the wing 10 f LOm t~le lower forward direction defining a predetermined angle of attack 24 with respect to a horizontal datum.
Mounted adjacent to the leading edge 14 of the wing 10 is at least one, but preferably a plurality, of la-terally spaced, forwardly extending finger members 30. As viewed in the figures, the fingers 30 are provided with a forward and trailing edge 32 and 34, respectively, and are also provided with upper surfaces 36 and lower surfaces 38. The upper and lower surfaces 36 and 38 meet at lateral edges 40A and 40B. As is discussed more fully herein, the fingers 30 define a predetermined cross sectional area when viewed as along section lines 2 - 2 in Figure 1. As shown in Figures 2 and 4, the fingers 30 are preferably biconve:; in cross section. The fi~ cl-s 8n may bc mounted directly to the upper surface 18 of the wing 10 adjacent the leading edge 14 thereof (as illustrated in Figure 2) or, alternatively, as illustrated in Figure 5, may be mounted a predetermined distance H thereabove on suitable struts 42 or the like. The fingers 30 may be pivotally mounted, if desired.
By whatever mode of attachment utilized, the fingers .~ -- 3 --,~" ,.,~.
1~5~
are spaced latercally a predc~cL-millcd di;~all(c ~, bci~c(~ll r centerlines of adjacent fingers 30. sy spaced lateral adjacency it is meant that adjacent finyers 30 are close enou~h together that adjacent vortices are in contact with each other.
Referring to Figure 4, it is seen that each finger 30 has a predetermined length 1, (measured along the forwardly projecting direction of the fingers), width w, (measured in a direction transverse to the forward direction), and heiallt h, definc(1 in accordance with Figure 4. It will be appreciated that the forward dimension 1 of the finger is at least equal to but preferably greater than its transverse dimension w as illustrated in Figure 4. In practical application, each aircraft wing will have appropriately configured and dimensioned fingers 30 for generating counter-rotating vortices of sufficient size and strength to remain intact until thcy reach substantially to or past the trailing cdge of Lll(~ willg.
That is to say, the fingers 30 are configured, dimensioned and mounted on the wing so as to generate a pair of counter-rotating, contacting vortices which are strong enough to remain intact and not dissipate over substantially the width of or the entire width of the wing behind the finaers. Bv way of examplc, suitable values for finger dimensions, in terms of the width of the wing C include: projection of the finger 30 forward of the edge 14 of the wing (distance 43, Fiaure 1), .29C; width w of finger, .167C; spacing L between fingers 30, .333C.
The fingers 30 may exhibit any of a predetermined plurality of configurations, as illustrated in Figures 6, 7, 8, 9, 10 and 11. The fingers 30 may cithcL^ bc ul~wal-dlv (~ .'.l, as viewed from the side as shown in Figure 6, downwardly curved as viewed from the side as shown in Figure 7, or may be T-shaped in cross section as viewed from the frontal view shown in Figure 8.
Further, as viewed in plan, the fingers 30 may be trapezoidal, with the short base extending forward of the edge 14 (Figure 9) or the long base forward of the edge i4 (~igures '0 and 11~
Further, the sides of the trapezoid may be straight (~igure 10), ~1~5~5 serrated (Figure 9) or curved (~i.gure 11), whetiler the short or long base is forwardly extending. The fingers, when viewed in plan, may also be triangular in -Eorm.
As mentioned, suitable means may be provided for extending the fingers 30 to their forwardly extending position adjacent the leading edge 14 of the wing 10, and retracting the fingers into a recess provided withill the WillCl (not showll), or disposing the finger 30 to any intermediate position therebetween. Furthermore, as viewed in Fiqure 5, the fingers 30 may be pivotally mounted, as at 44, with the points of attachment of the finger 30 to the strut 92, or between thc strut 42 and the surface 18 of the wing 10, so as to be moveable either upwardly or downwardly, lateral.lv from siAe-to-side, or both, as may be necessary in certain situations. Suitable means for con-trolling the upward or downward lateral. movelnellt of the fingers may be provided.
In operation, the wing lift clevice l2, incluAing the fingers 30, has the effect of changing the airflow patterns with respect to the upper surface 18 of the wing 10. This is believed to be an effect of a counter-rotati.ng vortcx system (Figures 1 and 2) trailing rearwardly from the fingers 30. As the airflow vector 22 impinges on the lower surfaces 38 of the fingers 30, the flow moves upwardly and around the lateral edges 40A and 40B of the fingers 30 to qenerate side-by-side counter-rotating vortices 50A and 50B (illustrated diagrammatically in Figures 1 and 2). By "counter-rotating vortices" it is meant that the pair of vortices 50A all~ 50s producecl frolll eacll fill-lel-30 are close enough toaether as to be in contact with and reinforce the other as they trail rearwardly in oppositely rotating directions across the surface of the wing behind the fingers. As seen from the front (Figure 2), the vortex 50A
rotates in a clockwise direction as it trails rearwardly over the upper surface 18 of the wing 10. The vortex 50B rotates in a counterclockwisc? dirccti.on as it tL-ai~s re~ wal ~ly O\'CI- tlle upper surface 18 of the wing 10.
'' ~ d`'~l-~s~
A consequence of the counter-rotatiny vortices is that the lift capability of the winy 10 is increased for a yiven angle of attack and air speed. Alternatively, decreased angles of attack or lower air speeds would be required to maintain the lift capability of the wing at a predetermined value. As a result takeoffs and landings at slower speeds and with shorter runways may be accomplished through the utilization of the wing lift device embodying the teachings of this invention.
Each of the projecting fingers 30 generate the counter-rotating vortices 50A~and 50B, as discussed above,-covering the upper surface 18 behind the fingers. As these vortices trail rearwardly over the top surface 18 of the wing, a possible mode of action is that these vortices 50 induce chan~es in the alrflow pattern over the surface 18 of the wing that extend considerably above the thickness dimension 52 (Fiyure 2) of the vortices 50. It is believed that the vortices 50 induce a second set of vortices above them which together create a blockage effect above the wing surface 18. As a result, the airflow over the upper surface 18 "humps" over the wing as if the wing curvature were greater than it actually is.
Consequently, increased lift is generated from the wing. It is also noted that airflow over the upper surface 18 of the wing do not sweep forwardly over the wing (the characteristic of the stall condition) until high angles of attack well past the usual stall region are attained. The finaers 30 projectinq forwardly from the wing 10 yenerate increased lift from the winq over a wide range from very low angles of attack, (wh~re there is no stall even with conventional wings), through angles of attack in the usual stall region, to relatively high angles of attack. As will be evident from Fiqures 1 to 3, for example, when the fingers 30 are directly attached to the leading edge of the wing, they are each tangentially mounted with respect to the wing's surface adjacent the leading edge. It will be appreciated that the arrangement of the fingers, their s angularity and location, although generatina the counter-rotatinq vortices, should not otherwise obstruct airflow over the wing surface 18. The fingers 30 are not intended and should be positioned and mounted on the leading edge to generate the counter-rotating vortices ancl ~ct not provic1e a s~oilcl c 1- rcc~ .
When the fingers are located above the wing (as in Figures 5 and 8), the space between the wing and the finger disposed thereabove allows a continuous airflow over the winq's surface to occur. Accordingly when the fingers 30 are attached directly to the leading edge of the wing, the fingers should be arranged to provide a smooth continuous airflow over the upper surface subject to the counter-rotating vorticcs and thus the trailing edge 34 of fingers 30 would in practice be smoothly aligned with or connected to the surface of the wing. The same would of course be the case where the wings are pivotally or retractably mounted. By "continuous airflow" it is meant that the fingers should be positioned so as to only generate the desired counter-rotating vortices and not provide a spoilel-effect.
As seen from Figure 12, the fingers 30 may be used adjacent the leading edge 14' of a swept back wing 10'. The fingers 30 have, if necessary, the leading edges 32' thereof angled along a common plane, as illustrated in Figure 12 to prevent mutual interference. The angled leading edges 32' may or may not be e~tended parallel to the leadillg edgc 14' of thc swept back wing.
Having described a preferred embodiment of the invention, those skilled in the art may effect modifications thereto in view of the teachings herein provided. Yet, it is understood that these modifications are within the contemplation of this invention, as defined in the appended claims.
~,~
Supplementary Disclosure In the principal disclosure it was indicated that fingers 30 may be pivotally mounted, as exemplified at 44 in Figure 5, so as to be moveable either upwardly or downwardly, laterally in a side-to-side, or botll, as ma~ be lleCe5S;II'~' 01-desirable in certain situations. Suitable means for controlling the upward, downward and/or lateral movement would be provided.
Similarly, it was disclosed in the principal disclosure, that suitable means may be provided for extendinq fingers 30 forwardly from a recess (not shown) to their forwardly extending position adjacent the leading edqe 14 of the wing 10 and for retracting the fingers into the recess.
Although various means of pivotally mounting the fingers are possible, it can be done by setting them in a gimbal mounting with vertical and transverse axes to allow for side-to-side and up-and-down rotational motions, respectively.
Rotations about other axes can be used. The motions can be accomplished by means of a lever arm e~te~ from e.lcll .~
at the end of which is a nut through which a threaded bolt is passed to form a jackscrew. An electric or hydraulic motor can be used to power the jackscrew. This mechanism allows the fingers to be positioned in any attitude and to be held rigidly in that attitude. It will be appreciated that once an attitude of the finger is selected, the fingers are to remain rigidly and securely in place.
An alternative mechanism would include a linear actuator to move the lever arms, with detents and an appropriate latching device such as a pin to fit the detent, the detents being located to obtain the best average position for two, or perhaps more, flight conditions. The actuator can be electrically or hydraulically powered. It is appreciated that any suitable means may be utilized to mount the fingers, move them in side-to-side and in up-and-down rotational motions, and ~1~5~
rigidly secure them in a selected attitude in accordance with the invention.
Similarly for extendina or retracting the fingers, the fingers may be moun-ted on guides to allow slidillg motioll, and either a jackscrew or a linear actuator with detents used to power the motion. A ~imbal system as described above can be included with the fingers mounted on the guides to simultaneously provide rotational motion.
~ _ 9 _ " ,c~: .
,~,
BACKGROUND OF THE INVENTION
Field of the Invention This invention relates to a wing lift device for increasing the lift capability of aircraft wings.
Description of the Prior Art Lift of an airplane wing is a function of its forward speed and angle of attack. For each type of wing there is an upper limit to the angle of attack that can be effectively reached, beyond which a stall suddenly occurs with almost total loss of lift. The separation of the boundary layer from the surface of the aircraft wing occurs at a point on the surface of the wing at increasingly forward points from the trailing edge thereof as the angle of attack is increased. Therefore, in order to accommodate larger and heavier aircraft, it is necessary that progressively higher takeoff and landing velocities be maintained in order to prevent stall of the wing and the loss of lift cap-ability. It would be advantageous, therefore, to increase the lift capability of aircraft wings by more efficiently utilizing the airflow across the top surface of the wing.
SUMMARY OF THE INVENTION
The invention in its broader aspect pertains to apparatus for increasing the lift generated by an aircraft wing, having upper and lower surfaces, while propelled through a fluid medium. The apparatus comprises a finger mounted adjacent to the leading edge of the wing and extending forwardly therefrom such that the finger is essentially tangential to the upper surface of the wing, the finger having lateral edges thereon.
C
The finger is mounted on the wing such that as the wing is propelled through the fluid medium impingement of the fluid medium on the finger produces, by flow around the lateral edges, a first and second vortex trailing rearwardly from the finger over the upper surface of the wing in the direction of fluid flow, each of the vortices being in contact with and counter-rotating with respect to the other. The finger is sized such that each vortex produced thereby is of sufficient size and strength to modify the flow pattern above the boundary layer on the wing upper surface so as to effect an increase in the lift.
More particularly, the invention relates to, in combination to an aircraft wing, a wing lift device including at least one, but preferably a plurality of laterally spaced, for-wardly extending finger members mounted adjacent to the forward edge of the airfoil. The fingers may be mounted directly on the airfoil or supported a predetermined distance thereabove by suit-able struts or the like. The forwardly extending fingers obstruct the airflow impinging thereon at predetermined angles of attack so as to generate counter-rotating vortices trailing backwardly therefrom over substantially the entire upper surface of the wing that lies behind the fingers as the airflow moves upwardly -la-C
and over the lateral edges of thc fingcrs. Thc rin~ers ~re sized and configured such that the counter-rotating vorticcs produced thereby are in contact one with the other and remain intact as vortices as they extend backwardly and trail over the upper surface of the aircraft wing. As a result of the counter-rotating vortices, a blockage effect is created which modifies the airflow patterns across the upper surface of the wing and to produce increased lift capability o~ tl-e Will'1~
BRIEF DESCRIPTION OF TIIE DR~WINGS
The invention will be more fully understood from the following detailed description of a preferred embodiment thereof, taken in connection with the accompanying drawings, which form a part of the specification, and in which:
Figure 1 is a plan view of an aircraft wing illustrating a wing lift device embodyinq the teachings of this invention;
Figure 2 is a front view taken along lines 2 - 2 of Figure l;
Figure 3 is a section view of the wing of Fiyure l;
Figure 4 is an isolated perspective view of one embodiment of a wing lift device in accordance with the teachings of the invention;
Figure 5 is a fragmentary view of an alternate mode of attachment of the wincr lift device to an aircraft wing;
Figures 6, 7, 8, 9, 10, 11 and 12 are alternate embodiments of the invention.
_ESCRIPTION OF THF PREFERRED EMBODIMENT
Throughout the following description, similar reference numerals refer to similar elements in all figures of the drawings.
Referring to Figures 1 through 3, an aircraft wing, generally indicated by reference numeral 10, of known airfoil configuration as viewed in the cross section of Figure 3 is ~, ~
shown in isolation from the remainder oE the aircraft fusclagc and like structures with which it is normally associated. It is understood that the wing 10 may be either a conventional straight wing or a swept-back wing and still be utilizable in connection with a wing lift device generally indicated by reference numeral 12 embodying the teachings of this invention.
The wing 10 includes a forward or leading edge 14 and a rearward or trailing edge 16. An upper surface 18 and a lower surface 20 are interposed to connect the forward and rearward edges 14 and 16, respectively. The width C of the wing 10 is the distance between the leading edge 14 and trailing edge 16 of the wing 10. For definitional purposes, the wing 10 will be assumed to be confronted by an airflow indicated by a vector 22 approaching the leading edge 14 of the wing 10 f LOm t~le lower forward direction defining a predetermined angle of attack 24 with respect to a horizontal datum.
Mounted adjacent to the leading edge 14 of the wing 10 is at least one, but preferably a plurality, of la-terally spaced, forwardly extending finger members 30. As viewed in the figures, the fingers 30 are provided with a forward and trailing edge 32 and 34, respectively, and are also provided with upper surfaces 36 and lower surfaces 38. The upper and lower surfaces 36 and 38 meet at lateral edges 40A and 40B. As is discussed more fully herein, the fingers 30 define a predetermined cross sectional area when viewed as along section lines 2 - 2 in Figure 1. As shown in Figures 2 and 4, the fingers 30 are preferably biconve:; in cross section. The fi~ cl-s 8n may bc mounted directly to the upper surface 18 of the wing 10 adjacent the leading edge 14 thereof (as illustrated in Figure 2) or, alternatively, as illustrated in Figure 5, may be mounted a predetermined distance H thereabove on suitable struts 42 or the like. The fingers 30 may be pivotally mounted, if desired.
By whatever mode of attachment utilized, the fingers .~ -- 3 --,~" ,.,~.
1~5~
are spaced latercally a predc~cL-millcd di;~all(c ~, bci~c(~ll r centerlines of adjacent fingers 30. sy spaced lateral adjacency it is meant that adjacent finyers 30 are close enou~h together that adjacent vortices are in contact with each other.
Referring to Figure 4, it is seen that each finger 30 has a predetermined length 1, (measured along the forwardly projecting direction of the fingers), width w, (measured in a direction transverse to the forward direction), and heiallt h, definc(1 in accordance with Figure 4. It will be appreciated that the forward dimension 1 of the finger is at least equal to but preferably greater than its transverse dimension w as illustrated in Figure 4. In practical application, each aircraft wing will have appropriately configured and dimensioned fingers 30 for generating counter-rotating vortices of sufficient size and strength to remain intact until thcy reach substantially to or past the trailing cdge of Lll(~ willg.
That is to say, the fingers 30 are configured, dimensioned and mounted on the wing so as to generate a pair of counter-rotating, contacting vortices which are strong enough to remain intact and not dissipate over substantially the width of or the entire width of the wing behind the finaers. Bv way of examplc, suitable values for finger dimensions, in terms of the width of the wing C include: projection of the finger 30 forward of the edge 14 of the wing (distance 43, Fiaure 1), .29C; width w of finger, .167C; spacing L between fingers 30, .333C.
The fingers 30 may exhibit any of a predetermined plurality of configurations, as illustrated in Figures 6, 7, 8, 9, 10 and 11. The fingers 30 may cithcL^ bc ul~wal-dlv (~ .'.l, as viewed from the side as shown in Figure 6, downwardly curved as viewed from the side as shown in Figure 7, or may be T-shaped in cross section as viewed from the frontal view shown in Figure 8.
Further, as viewed in plan, the fingers 30 may be trapezoidal, with the short base extending forward of the edge 14 (Figure 9) or the long base forward of the edge i4 (~igures '0 and 11~
Further, the sides of the trapezoid may be straight (~igure 10), ~1~5~5 serrated (Figure 9) or curved (~i.gure 11), whetiler the short or long base is forwardly extending. The fingers, when viewed in plan, may also be triangular in -Eorm.
As mentioned, suitable means may be provided for extending the fingers 30 to their forwardly extending position adjacent the leading edge 14 of the wing 10, and retracting the fingers into a recess provided withill the WillCl (not showll), or disposing the finger 30 to any intermediate position therebetween. Furthermore, as viewed in Fiqure 5, the fingers 30 may be pivotally mounted, as at 44, with the points of attachment of the finger 30 to the strut 92, or between thc strut 42 and the surface 18 of the wing 10, so as to be moveable either upwardly or downwardly, lateral.lv from siAe-to-side, or both, as may be necessary in certain situations. Suitable means for con-trolling the upward or downward lateral. movelnellt of the fingers may be provided.
In operation, the wing lift clevice l2, incluAing the fingers 30, has the effect of changing the airflow patterns with respect to the upper surface 18 of the wing 10. This is believed to be an effect of a counter-rotati.ng vortcx system (Figures 1 and 2) trailing rearwardly from the fingers 30. As the airflow vector 22 impinges on the lower surfaces 38 of the fingers 30, the flow moves upwardly and around the lateral edges 40A and 40B of the fingers 30 to qenerate side-by-side counter-rotating vortices 50A and 50B (illustrated diagrammatically in Figures 1 and 2). By "counter-rotating vortices" it is meant that the pair of vortices 50A all~ 50s producecl frolll eacll fill-lel-30 are close enough toaether as to be in contact with and reinforce the other as they trail rearwardly in oppositely rotating directions across the surface of the wing behind the fingers. As seen from the front (Figure 2), the vortex 50A
rotates in a clockwise direction as it trails rearwardly over the upper surface 18 of the wing 10. The vortex 50B rotates in a counterclockwisc? dirccti.on as it tL-ai~s re~ wal ~ly O\'CI- tlle upper surface 18 of the wing 10.
'' ~ d`'~l-~s~
A consequence of the counter-rotatiny vortices is that the lift capability of the winy 10 is increased for a yiven angle of attack and air speed. Alternatively, decreased angles of attack or lower air speeds would be required to maintain the lift capability of the wing at a predetermined value. As a result takeoffs and landings at slower speeds and with shorter runways may be accomplished through the utilization of the wing lift device embodying the teachings of this invention.
Each of the projecting fingers 30 generate the counter-rotating vortices 50A~and 50B, as discussed above,-covering the upper surface 18 behind the fingers. As these vortices trail rearwardly over the top surface 18 of the wing, a possible mode of action is that these vortices 50 induce chan~es in the alrflow pattern over the surface 18 of the wing that extend considerably above the thickness dimension 52 (Fiyure 2) of the vortices 50. It is believed that the vortices 50 induce a second set of vortices above them which together create a blockage effect above the wing surface 18. As a result, the airflow over the upper surface 18 "humps" over the wing as if the wing curvature were greater than it actually is.
Consequently, increased lift is generated from the wing. It is also noted that airflow over the upper surface 18 of the wing do not sweep forwardly over the wing (the characteristic of the stall condition) until high angles of attack well past the usual stall region are attained. The finaers 30 projectinq forwardly from the wing 10 yenerate increased lift from the winq over a wide range from very low angles of attack, (wh~re there is no stall even with conventional wings), through angles of attack in the usual stall region, to relatively high angles of attack. As will be evident from Fiqures 1 to 3, for example, when the fingers 30 are directly attached to the leading edge of the wing, they are each tangentially mounted with respect to the wing's surface adjacent the leading edge. It will be appreciated that the arrangement of the fingers, their s angularity and location, although generatina the counter-rotatinq vortices, should not otherwise obstruct airflow over the wing surface 18. The fingers 30 are not intended and should be positioned and mounted on the leading edge to generate the counter-rotating vortices ancl ~ct not provic1e a s~oilcl c 1- rcc~ .
When the fingers are located above the wing (as in Figures 5 and 8), the space between the wing and the finger disposed thereabove allows a continuous airflow over the winq's surface to occur. Accordingly when the fingers 30 are attached directly to the leading edge of the wing, the fingers should be arranged to provide a smooth continuous airflow over the upper surface subject to the counter-rotating vorticcs and thus the trailing edge 34 of fingers 30 would in practice be smoothly aligned with or connected to the surface of the wing. The same would of course be the case where the wings are pivotally or retractably mounted. By "continuous airflow" it is meant that the fingers should be positioned so as to only generate the desired counter-rotating vortices and not provide a spoilel-effect.
As seen from Figure 12, the fingers 30 may be used adjacent the leading edge 14' of a swept back wing 10'. The fingers 30 have, if necessary, the leading edges 32' thereof angled along a common plane, as illustrated in Figure 12 to prevent mutual interference. The angled leading edges 32' may or may not be e~tended parallel to the leadillg edgc 14' of thc swept back wing.
Having described a preferred embodiment of the invention, those skilled in the art may effect modifications thereto in view of the teachings herein provided. Yet, it is understood that these modifications are within the contemplation of this invention, as defined in the appended claims.
~,~
Supplementary Disclosure In the principal disclosure it was indicated that fingers 30 may be pivotally mounted, as exemplified at 44 in Figure 5, so as to be moveable either upwardly or downwardly, laterally in a side-to-side, or botll, as ma~ be lleCe5S;II'~' 01-desirable in certain situations. Suitable means for controlling the upward, downward and/or lateral movement would be provided.
Similarly, it was disclosed in the principal disclosure, that suitable means may be provided for extendinq fingers 30 forwardly from a recess (not shown) to their forwardly extending position adjacent the leading edqe 14 of the wing 10 and for retracting the fingers into the recess.
Although various means of pivotally mounting the fingers are possible, it can be done by setting them in a gimbal mounting with vertical and transverse axes to allow for side-to-side and up-and-down rotational motions, respectively.
Rotations about other axes can be used. The motions can be accomplished by means of a lever arm e~te~ from e.lcll .~
at the end of which is a nut through which a threaded bolt is passed to form a jackscrew. An electric or hydraulic motor can be used to power the jackscrew. This mechanism allows the fingers to be positioned in any attitude and to be held rigidly in that attitude. It will be appreciated that once an attitude of the finger is selected, the fingers are to remain rigidly and securely in place.
An alternative mechanism would include a linear actuator to move the lever arms, with detents and an appropriate latching device such as a pin to fit the detent, the detents being located to obtain the best average position for two, or perhaps more, flight conditions. The actuator can be electrically or hydraulically powered. It is appreciated that any suitable means may be utilized to mount the fingers, move them in side-to-side and in up-and-down rotational motions, and ~1~5~
rigidly secure them in a selected attitude in accordance with the invention.
Similarly for extendina or retracting the fingers, the fingers may be moun-ted on guides to allow slidillg motioll, and either a jackscrew or a linear actuator with detents used to power the motion. A ~imbal system as described above can be included with the fingers mounted on the guides to simultaneously provide rotational motion.
~ _ 9 _ " ,c~: .
,~,
Claims (22)
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. Apparatus for increasing the lift generated by an aircraft wing, having upper and lower surfaces, while propelled through a fluid medium comprising:
a finger mounted adjacent to the leading edge of said wing and extending forwardly therefrom such that the finger is essentially tangential to the upper surface of said wing, said finger having lateral edges thereon, said finger being mounted on the wing such that as the wing is propelled through the fluid medium impingement of the fluid medium on said finger produces, by flow around said lateral edges, a first and second vortex trailing rearwardly from said finger over the upper surface of the wing in the direction of fluid flow, each of said vortices being in contact with and counter-rotating with respect to the other, said finger being sized such that each vortex produced thereby is of sufficient size and strength to modify the flow pattern above the boundary layer on the wing upper surface so as to effect an increase in the lift.
a finger mounted adjacent to the leading edge of said wing and extending forwardly therefrom such that the finger is essentially tangential to the upper surface of said wing, said finger having lateral edges thereon, said finger being mounted on the wing such that as the wing is propelled through the fluid medium impingement of the fluid medium on said finger produces, by flow around said lateral edges, a first and second vortex trailing rearwardly from said finger over the upper surface of the wing in the direction of fluid flow, each of said vortices being in contact with and counter-rotating with respect to the other, said finger being sized such that each vortex produced thereby is of sufficient size and strength to modify the flow pattern above the boundary layer on the wing upper surface so as to effect an increase in the lift.
2. The wing lift device of claim 1 further comprising a second finger mounted at the forward edge of the aircraft wing and extending forwardly therefrom and in spaced lateral adjacency to said finger such that the second finger is essentially tangential to the upper surface of said wing, said second finger having lateral edges thereon, impingement of an airflow on said second finger generating, by flow around said lateral edges, a second set of contacting counter-rotating vortices trailing rearwardly over the upper surface of said wing, one of said second set of vortices being in contact with the other of said vortices generated from said finger, the second finger being sized such that each of the vortices generated by said second finger is of sufficient size and strength to modify the flow pattern above the boundary layer on the wing upper surface to effect an increase in the lift.
3. The wing lift device of claim 1 wherein said finger is pivotable upwardly and downwardly relative to the upper surface of the wing.
4. The wing lift device of claim 1 or 2 wherein said finger is pivotable laterally from side-to-side relative to the upper surface of the wing.
5. The wing lift device of claim 3 wherein said finger is pivotable laterally from side-to-side with respect to the surface of the wing.
6. The wing lift device of claim 1, 2 or 5 wherein said finger is substantially biconvex in frontal cross section.
7. The wing lift device of claim 1, 2 or 5 wherein said finger is substantially T-shaped in frontal cross section.
8. The wing lift device of claim 1, 2 or 5 wherein said finger is substantially curved upwardly with respect to the surface of the wing.
9. The wing lift device of claim 1, 2 or 5 wherein said finger is curved downwardly with respect to the upper surface of the wing .
10. The wing lift device of claim 1 wherein said finger is substantially trapezoidal in plan.
11. The wing lift device of claim 10 wherein the long base of said finger is mounted adjacent to the leading edge of the wing.
12. The wing lift device of claim 10 wherein the short base of the trapezoid is mounted adjacent to the wing attachment point at the leading edge of the aircraft wing.
13. The wing lift device of claim 10 wherein the sides of the trapezoid are straight lines.
14. The wing lift device of claim 10 wherein the sides of the trapezoid are curved lines.
15. The wing lift device of claim 2 wherein the leading edges of each finger are angled in a common plane.
16. The wing lift device of claim 2 wherein said aircraft wing is a straight wing.
17. The wing lift device of claim 15 wherein said aircraft wing is a swept back wing.
18. The wing lift device of claim 17 wherein said angle of said leading edge of said fingers is parallel to the leading edge of said swept back wing.
19. The wing lift device of claim 1 wherein the fingers are of rectangular plan form.
20. The wing lift device of claim l where said contacting opposed vortices remain intact as vortices above the entire upper surface of the wing behind the finger.
21. The wing lift device of claim 2 wherein said fingers are of rectangular plan form and substantially biconvex in frontal cross section and wherein said contacting opposed vortices produced therefrom remain intact as vortices above the entire upper surface of the wing behind the fingers and wherein vortices produced by said fingers contact each other.
Claims Supported by Supplementary Disclosure
Claims Supported by Supplementary Disclosure
22. The wing lift device of claims 3, 4 or 5 wherein means for pivotally mounting said fingers include gimbal mounting means, lever means operatively associated with said gimbal mounting means and selectively powered jackscrew means operatively associated with said lever means for positioning said fingers in a desired position.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US81673277A | 1977-07-18 | 1977-07-18 | |
| US816,732 | 1977-07-18 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1105915A true CA1105915A (en) | 1981-07-28 |
Family
ID=25221472
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA306,774A Expired CA1105915A (en) | 1977-07-18 | 1978-07-04 | Counter-rotating vortices generator for an aircraft wing |
Country Status (4)
| Country | Link |
|---|---|
| CA (1) | CA1105915A (en) |
| DE (1) | DE2830371A1 (en) |
| FR (1) | FR2397977A1 (en) |
| GB (1) | GB2001024B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3521329A1 (en) * | 1985-06-14 | 1986-12-18 | Messerschmitt-Bölkow-Blohm GmbH, 8012 Ottobrunn | Vortex generator and boundary layer deflector arrangement |
| DE4208751A1 (en) * | 1992-02-27 | 1993-11-11 | Fritz Karl Hausser | Reducing resistance to aerofoil or hydrofoil passing through medium e.g. air or water - uses array of teeth formed on leading and/or trailing edge of aerofoil or hydrofoil section |
| CN113581459B (en) * | 2021-08-13 | 2023-01-31 | 中电科芜湖钻石飞机制造有限公司 | High lift assembly for composite wing aircraft and composite wing aircraft |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1809593B2 (en) * | 1968-11-18 | 1974-07-18 | Messerschmitt-Boelkow-Blohm Gmbh, 8000 Muenchen | Device for influencing the eddies on the upper side of wings |
-
1978
- 1978-07-04 CA CA306,774A patent/CA1105915A/en not_active Expired
- 1978-07-10 GB GB7829360A patent/GB2001024B/en not_active Expired
- 1978-07-11 DE DE19782830371 patent/DE2830371A1/en active Granted
- 1978-07-17 FR FR7821149A patent/FR2397977A1/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| GB2001024A (en) | 1979-01-24 |
| GB2001024B (en) | 1982-04-21 |
| FR2397977A1 (en) | 1979-02-16 |
| DE2830371A1 (en) | 1979-02-08 |
| FR2397977B1 (en) | 1983-11-10 |
| DE2830371C2 (en) | 1988-03-10 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4323209A (en) | Counter-rotating vortices generator for an aircraft wing | |
| US5072894A (en) | Apparatus and method for increasing the angle of attack operating range of an aircraft | |
| US4739957A (en) | Strake fence flap | |
| US7661630B2 (en) | High lift longitudinal axis control system | |
| US6098923A (en) | Aircraft structure to improve directional stability | |
| US5772155A (en) | Aircraft wing flaps | |
| US5108044A (en) | Shroud-fin integration shelf for a helicopter empennage structure | |
| JPS647920B2 (en) | ||
| US6513761B2 (en) | Method and apparatus for reducing trailing vortices in the wake of an aircraft | |
| US4466586A (en) | Directional control device for aircraft | |
| CA1324120C (en) | Thrust-deflecting vane devices of v/stol aircraft | |
| US3172621A (en) | Airfoil | |
| US4429843A (en) | Counter-rotating vortices generator for an aircraft wing | |
| US4381091A (en) | Control-effect enhancement of tiltable aircraft stabilizing member | |
| US4291853A (en) | Airplane all-moving airfoil with moment reducing apex | |
| US4227665A (en) | Fixed leading edge slat spoiler for a horizontal stabilizer | |
| CA1105915A (en) | Counter-rotating vortices generator for an aircraft wing | |
| US4358077A (en) | Transverse wing actuation system | |
| US4442986A (en) | Leading edge augmentor wing-in-ground effect vehicle | |
| US4582276A (en) | Lifting shock wave cancellation module | |
| EP0052360B1 (en) | Air aspiration device of aircraft-mounted gas-turbine engine | |
| US3009670A (en) | Airplane with adjustable wings and tail | |
| US4440361A (en) | Aircraft structure | |
| EP1100718B1 (en) | An aircraft fin and rudder | |
| JPH07132893A (en) | Rotary-wing aircraft |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |