WO1991009776A1 - Profil d'aile ameliore par un venturi - Google Patents

Profil d'aile ameliore par un venturi Download PDF

Info

Publication number
WO1991009776A1
WO1991009776A1 PCT/US1990/007687 US9007687W WO9109776A1 WO 1991009776 A1 WO1991009776 A1 WO 1991009776A1 US 9007687 W US9007687 W US 9007687W WO 9109776 A1 WO9109776 A1 WO 9109776A1
Authority
WO
WIPO (PCT)
Prior art keywords
airfoil
port
gas
aperture
extending
Prior art date
Application number
PCT/US1990/007687
Other languages
English (en)
Inventor
Mark T. Willis
Sterge T. Demetriades
M. Edmund Ellion
Martin Brouillette
Frank E. Marble
Craig D. Maxwell
Gregoire S. Winckelmans
Kostanenos N. Hronopoulos
Original Assignee
Venturi Applications, Inc.
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Venturi Applications, Inc. filed Critical Venturi Applications, Inc.
Publication of WO1991009776A1 publication Critical patent/WO1991009776A1/fr

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D5/00—Blades; Blade-carrying members; Heating, heat-insulating, cooling or antivibration means on the blades or the members
    • F01D5/12—Blades
    • F01D5/14—Form or construction
    • F01D5/141—Shape, i.e. outer, aerodynamic form
    • F01D5/145—Means for influencing boundary layers or secondary circulations
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B64—AIRCRAFT; AVIATION; COSMONAUTICS
    • B64C—AEROPLANES; HELICOPTERS
    • B64C21/00—Influencing air flow over aircraft surfaces by affecting boundary layer flow
    • B64C21/02—Influencing air flow over aircraft surfaces by affecting boundary layer flow by use of slot, ducts, porous areas or the like
    • B64C21/025—Influencing air flow over aircraft surfaces by affecting boundary layer flow by use of slot, ducts, porous areas or the like for simultaneous blowing and sucking
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B64—AIRCRAFT; AVIATION; COSMONAUTICS
    • B64C—AEROPLANES; HELICOPTERS
    • B64C2230/00—Boundary layer controls
    • B64C2230/04—Boundary layer controls by actively generating fluid flow
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B64—AIRCRAFT; AVIATION; COSMONAUTICS
    • B64C—AEROPLANES; HELICOPTERS
    • B64C2230/00—Boundary layer controls
    • B64C2230/06—Boundary layer controls by explicitly adjusting fluid flow, e.g. by using valves, variable aperture or slot areas, variable pump action or variable fluid pressure
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B64—AIRCRAFT; AVIATION; COSMONAUTICS
    • B64C—AEROPLANES; HELICOPTERS
    • B64C2230/00—Boundary layer controls
    • B64C2230/28—Boundary layer controls at propeller or rotor blades
    • 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
    • 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
    • Y02T50/60—Efficient propulsion technologies, e.g. for aircraft

Definitions

  • the present invention relates to devices for increasing the lift of an airfoil by airflow circulation control and reaction forces.
  • the devices available for improving the performance of aircraft airfoils divide naturally into two groups: (1) high-lift devices to optimize aircraft performance during take-off and landing, and (2) devices that increase the ratio of lift-to-drag to optimize steady- state cruise performance.
  • Known devices for increasing lift include the fan-in-wing, ducted fan-in-wing, jet flap, blown flap, ejector and Coanda jet.
  • the known devices offer some benefits, they have significant disadvantages.
  • a typical airfoil provides lift by causing the air that flows across the upper surface to accelerate to a high velocity, and the air that flows across the lower surface to flow at a lower velocity. The difference in velocity results in a lower pressure on the upper surface as compared to the pressure on the lower surface. The differential in pressure thus generates a lifting force on the airfoil.
  • Design for increasing lift by controlling the airflow across the airfoil thus aim to increase the velocity difference, and consequently the pressure difference between the upper and lower surfaces of the airfoil. This is commonly referred to as “circulation control.”
  • Lift can also be generated by reaction forces against the airfoil, which is different than circulation control. These lifting reaction forces act in the same way as the forward thrust of a propeller or jet engine, except that the discharged gas is oriented downward rather than horizontally rearward.
  • One device to increase the lift of an airfoil is the trailing edge flap.
  • a movable flap is mounted on the trailing edge of the airfoil, so that the aft section of the airfoil is movable. When the flap is in a downward orientation, the air flowing under the airfoil is deflected downwardly, resulting in an increased pressure and thus a higher lift.
  • This device is used in modern aircraft to provide increased lift during take-off, as well as to slow the aircraft during landing.
  • trailing edge flap causes substantial drag when in the extended downward position, thus making it undesirable for cruise operation.
  • Another problem arises under certain flap conditions, that cause the airflow over the upper surface of the flap to separate. The separation causes the pressure against the upper surface to increase and therefore decreases the lift.
  • One technique for preventing the separation of airflow over the upper surface of a trailing edge flap is to provide a slotted flap.
  • a slot is extended through the flap. Air is permitted to flow from the high pressure side under the aifoil, through the slot, and into the low pressure side on the upper surface of the airfoil.
  • the slotted flap thus provides a high velocity jet that energizes the boundary layer on the upper surface and therefore prevents, or at least delays separation.
  • the slotted flap performs reasonably well in controlling separation, the air flowing from under the airfoil into the slot decreases the pressure under the airfoil, and consequently decreases the lift.
  • there is a trade-off in preventing separation on the upper surface of the airfoil a decrease in lift due to the lower pressure on the under surface, for the increase in lift provided by preventing separation on the upper surface of the flap.
  • the blown flap is a natural extension of the slotted flap.
  • the blown flap uses compressed air generated in a main aircraft engine or an auxiliary compressor, rather than the air from the under surface of the airfoil, as with the slotted flap. While the blown flap prevents flow separation and avoids the disadvantages of the slotted flap in using air from the under surface of the airfoil, it requires an external power source which lowers the overall efficiency of the aircraft.
  • the Coanda jet utilizes a high velocity jet directed tangentially to a convex surface, to cause a main stream of air to flow around the convex surface without separation. Without a Coanda jet, air flowing around a convex surface would tend to flow in a straight line and separate from the surface. However, when a Coanda jet is directed tangentially to a convex surface, the boundary layer is energized, causing the main stream to remain attached for some distance. Thus, a Coanda jet can be used to increase lift by circulation control. The Coanda jet, however, performs inefficiently during cruise because its low mass, high velocity jet is inherently inefficient for propulsion.
  • the jet flap is a thin sheet of high velocity air discharged along the trailing edge at an angle directed below the cord line of the airfoil.
  • the effect of the jet of air is similar to that of the trailing edge flap, in that it directs the airflow under the wing downwardly, resulting in an increased lift.
  • the jet provides some lift and forward thrust by its reaction force against the wing. Because the jet has a high velocity and appreciable surface area, it also entrains air, thus increasing the airflow over the wing and in turn increasing the lift by circulation control.
  • the jet flap Since power must be expended to pressurize the air that forms the jet, it is important that the jet flap operate efficiently during take-off, landing and cruise.
  • the jet flap performs efficiently during take-off and landing because its low mass, high velocity jet is effective for circulation control.
  • the jet flap performs poorly during cruise because, like the Coanda jet, its low mass, high velocity jet is inherently inefficient for propulsion.
  • the fan-in-wing generates a high-mass, low-velocity air stream, and thus unlike the jet flap, the fan-in-wing is an inherently efficient propulsion device.
  • a fan-in- wing can provide significant lift during take-off and landing.
  • a fan-in-wing generally comprises a fan mounted within a hole in the wing. The flow axis of the fan is oriented substantially perpendicular to the chord line of the wing. A portion of the air above the wing is drawn into the fan, compressed, and discharged through an exit port in the underside of the wing. If the fan is installed in a relatively thin wing or airfoil, the entrance and exit ports must be circular and the axis of the fan substantially vertical to the chord line of the airfoil.
  • the downward flow of air through the fan produces a reaction force and thus an upward lift on the wing.
  • the air drawn into the fan has a relatively low velocity, and low surface area in comparison to its volume, the fan does not entrain much air.
  • the fan-in-wing therefore causes very little additional air to flow over the wing, and consequently cannot be used effectively for circulation control.
  • the discharged air stream has an approximately circular cross-sectional configuration and is directed substantially perpendicular to the under surface of the wing.
  • the discharged air does not attach to the aft lower surface of the wing.
  • the resulting lower pressure in the aft region of the airfoil decreases the lift.
  • the fan-in-wing thus provides good take-off and landing performance, but cannot be used during cruise; the separation under the aft section of the wing decreases lift and generates substantial drag. Since the fan-in- wing cannot be used effectively during cruise, the entrance and exit ports must be covered with relatively complicated closure mechanisms to lower the drag caused by separation. The appreciable weight of the fan system and the complexities of the closures make the fan-in- wing an unattractive alternative for increasing lift.
  • a ducted fan-in-wing is a fan mounted within a circular hole extending through a wing.
  • a shroud surrounds the fan and is spaced apart from the wall defining the hole in the wing. Because of the shroud, an additional amount of air is entrained through the hole in the wing. The result is that for the same quantity of air pumped through the fan, there is a greater flow of discharged air from the under surface of the wing, than with the fan-in-wing. Therefore, the upward thrust of the ducted fan-in-wing is typically greater than the fan-in-wing.
  • the ducted fan-in-wing provides efficient lift during take-off and landing due to its reaction force, it has the same disadvantages as the fan-in-wing during cruise operation. The circular entrance and exit ports, and the flow separation under the aft section of the airfoil severely inhibit efficient cruise operation.
  • An ejector injects a small quantity of high velocity gas into a duct to entrain free stream air and thus act as a pump.
  • the entrance and exit ports can be shaped as desired, and do not have to be circular, as with the fan-in-wing and ducted fan-in-wing.
  • the exit port can be oriented and configured to cause the discharged air to remain attached to the under surface of an airfoil.
  • the ejector is simple, reliable, and flexible with regard to packaging, it is far less efficient than most mechanical pumps, such as the fan. Consequently, the overall efficiency of an aircraft employing an ejector, and not a mechanical pump, is likely to be significantly lower.
  • Applicant's novel airfoil has application in both a fixed horizontal airfoil of an aircraft or its structure may be incorporated into the vertical rudder of the tail section of an aircraft or helicopter.
  • the leading edge of the airfoil causes air to flow across both the upper and lower surfaces of the airfoil.
  • the velocity of air passing over the upper surface of the airfoil is greater than that passing beneath its lower surface, thus causing a lower pressure on the top surface of the airfoil.
  • the lower pressure results in a lift of the airfoil itself in a static condition.
  • Applicant's novel venturi assembly is incorporated into the airfoil adjacent to the trailing edge thereof.
  • the venturi has an entry port at its upper end and an exit port at its lower end.
  • the entry port and the exit port each have a greater circumference than a throat portion located therebetween.
  • a plurality of air nozzles are spaced around the circumference of the venturi at a position between the throat and the exit port thereof.
  • the air nozzles are in communication with a plenum chamber within the airfoil.
  • the plenum chamber is supplied with pressurized air from either the engine of the aircraft or some auxiliary source.
  • the airfoil thus produces an air-driven venturi which creates a strong suction on the upper surface of the airfoil. This further increases the velocity of air passing over the top surface of the airfoil, and thus further decreases the pressure on the top side of the airfoil.
  • the air which is sucked down through the venturi assembly further increases the high pressure force on the bottom of the airfoil and slows the velocity of air passing along the lower surface of the airfoil. The combination of these different forces results in additional lift performance for the airfoil itself.
  • the venturi assembly defines a vertical axis and can be incorporated into an airfoil so that the vertical axis is located at an angle with respect to the horizontal axis of the airfoil within a range of about two to twenty degrees. This inclination results in a vectored thrust in the forward direction that the wing would be traveling in.
  • the geometrical configuration of the venturi , s aperture can be circular, elongated oval shaped, or other desired geometrical shapes. There may be more than one venturi assembly formed adjacent to the trailing edge of an airfoil.
  • the venturi-enhanced airfoil can also be incorporated into the rudder of the tail of an aircraft or helicopter.
  • the rudder can have either a single venturi assembly incorporated therein or multiple venturi assemblies incorporated therein.
  • one venturi assembly can have its entry port on one vertical side of the airfoil and the other venturi assembly can have its entry port on the opposite side of the airfoil.
  • the venturi's can create their suction effects on both sides of the airfoil, which in turn can move the airfoil in either direction in a static condition. This effect can be created by increasing and decreasing the pressurized air flow in the particular venturi in order to move the airfoil in the desired direction.
  • the exhaust gas from the turbine of the helicopter is ducted to the front of the vertical venturi-enhanced airfoil which is mounted on the end of the helicopter's tail boom.
  • the venturi-enhanced airfoil acts as a rudder with the enhanced pressure differential acting against the main rotor torque.
  • the present invention is also directed to an airfoil defining an upper surface, a lower surface, and a first aperture extenting therethrough.
  • the first aperture is located in about the aft half section of the airfoil.
  • the first aperture is defined by an inlet port extending through the upper surface, an exit port extending through the lower surface, and a wall extending therebetween.
  • the exit port is located farther aft on the airfoil than the inlet port.
  • the wall defines at least one suction port extending therethrough, and at least one injection port extending therethrough. The injection port is located downstream of the suction port.
  • the aircraft further comprises means for generating pressurized gas coupled to the suction port and to the injection port.
  • the means for generating pressurized gas draws gas through the inlet port and through the suction port, compresses the gas, and in turn injects the gas through the injection port.
  • the gas flowing into the suction port causes additional gas to be entrained into the first aperture.
  • the gas flowing through the injection port further entrains gas within the first aperture.
  • the stream of gas is discharged through the exit port and across the trailing edge of the airfoil.
  • the lift on the airfoil of the present invention is thus increased by the reaction forces of the jet of air discharged through the exit port of the first aperture, and by circulation control.
  • the wall defining the first aperture includes a throat section.
  • the cross-sectional area of the first aperture in the throat section is less than its cross- sectional area in either the inlet port or the exit port.
  • a converging section converges inwardly from the inlet port and terminates on the throat section.
  • a diverging section diverges outwardly from the throat section and terminates on the lower surface.
  • the at least one suction port extends through the converging section, and the at least one injection port extends through the throat section.
  • the first aperture defines a longitudinal axis extending therethrough, which is oriented at an angle less than about 45° with respect to the chord line of the airfoil.
  • One advantage of the airfoil of the present invention is that the combined action of the suction port and the injection port generate a significant flow of air through the first aperture in a manner analogous to the ducted fan-in-wing.
  • the airfoil of the present invention therefore emulates the advantages of the ducted fan-in-wing.
  • the entrance and exit ports of the first aperture do not have to be circular, as with the ducted fan-in-wing.
  • the discharged air can be controlled to prevent separation from the under surface of the wing.
  • the airfoil embodying the present invention therefore provides significant advantages over the prior art devices for increasing lift.
  • Figure 1 is a partial top plan view illustrating applicant's novel airfoil
  • Figure 2 is a schematic cross-sectional elevation view taken along line 2-2 of Figure 1;
  • Figure 3 is a partial top plan view illustrating a first alternative venturi-enhanced airfoil
  • Figure 4 is a schematic cross-sectional elevational view taken along line 4-4 of Figure 3;
  • Figure 5 is a schematic illustration that indicates how air is supplied to the venturi assemblies
  • Figure 6 is a side elevation view of the venturi- enhanced airfoil utilized in the tail of an aircraft
  • Figure 7 is a horizontal cross-sectional view taken along line 7-7 of Figure 6;
  • Figure 8 is a first alternative embodiment of the venturi-enhanced airfoil utilized in the tail of an aircraft
  • Figure 9 is a horizontal cross-sectional view taken along line 9-9 of Figure 8.
  • Figure 10 is a horizontal cross-sectional view taken along line 10-10 of Figure 8;
  • Figure 11 is a partial cross-sectional view illustrating a modified venturi assembly in the horizontal fixed airfoil of an aircraft; -13-
  • Figure 12 is a schematic cross-sectional view of another airfoil embodying the present invention.
  • Figure 13 is a schematic cross-sectional view of the airfoil of Figure 12 illustrating the trailing edge flap rotated downwardly;
  • Figure 14 is a schematic cross-sectional view of the airfoil of Figure 12, illustrating the trailing edge flap rotated inwardly to form a Coanda jet on the trailing edge;
  • Figure 15 is a schematic cross-sectional view of another airfoil embodying the present invention.
  • Figure 16 is a schematic cross-sectional view of another airfoil embodying the present invention.
  • Figure 17 is a top plan view of a fixed wing aircraft employing the airfoil of Figure 16;
  • Figure 18 is a schematic illustration of a turbine blade mounted on a rotating turbine shaft
  • Figure 19 is an enlarged cross-sectional view of the turbine blade of Figure 18, taken along the line A-A;
  • Figure 20 is an enlarged cross-sectional view of another embodiment of the turbine blade of Figure 18, taken along the line A-A;
  • Figure 21 is an enlarged cross-sectional view of another embodiment of the turbine blade of Figure 18, taken along the line A-A;
  • Figure 22 is an enlarged cross-sectional view of another embodiment of the turbine blade of Figure 18, taken along the line A-A;
  • Figure 23 is an enlarged cross-sectional view of another embodiment of the turbine blade of Figure 18, taken along the line A-A;
  • Figure 24 is a schematic illustration of another turbine blade mounted on a rotating turbine shaft.
  • Figure 25 is an enlarged cross-sectional view of the turbine blade of Figure 24, taken along the line B-B.
  • FIG. 1 the fixed wing airfoil is generally designated by the reference numeral 16.
  • the airfoil 16 has a leading edge 17, a trailing edge 18, an upper surface 19, and a lower surface 20.
  • a deflector cap 22 is mounted adjacent to and covering the leading edge 17.
  • a venturi assembly 24 is located adjacent to the trailing edge 18.
  • a plenum chamber 21 is positioned in the leading edge 17, and pressurized air is released through an orifice 21a to travel over both the respective upper and lower surfaces 19 and 20.
  • the venturi assembly 24 has an entry port 25, an exit port 26, and a throat 27.
  • the venturi assembly 24 has a vertical x-axis with respect to the y-axis.
  • the y-axis has a forward inclination with respect to the x-axis and this may be designed within the range of about two to twenty degrees.
  • Positioned slightly below the throat 27 are a plurality of air nozzles 30 that are in communication with a plenum chamber 32.
  • Conventional ducting (not shown) is connected to plenum chamber 32 from a source of pressurized air, such as the exhaust of the aircraft.
  • a source of pressurized air such as the exhaust of the aircraft.
  • the airfoil illustrated in Figure 3 is designated generally by the reference numeral 40.
  • the airfoil 40 has a leading edge 41, a trailing edge 42, an upper
  • the airfoil 40 further defines a plurality of venturi assemblies 45 each having an elongated oval shape.
  • Each venturi assembly 45 has an entry port 47, an exit port 48, and a throat 49.
  • Air nozzles 50 are in communication with a
  • FIG 6 an embodiment is illustrated that shows the venturi-enhanced airfoil incorporated into the tail 53 of the fuselage 54 of an aircraft.
  • the tail 53 may be
  • the airfoil 56 functions as the rudder of the aircraft, and it pivots about an axis 58. Utilizing the same descriptive designations to airfoil 56 as that of the horizontally oriented
  • a venturi assembly 65 has an entry port 66, an exit port 67, and a throat 68.
  • a plurality of air nozzles 70 are in communication with a plenum chamber 72. The plenum
  • 30 chamber 72 would have conventional ducting from a pressurized air supply source.
  • An airfoil 75 has a leading edge 76, a trailing edge 77, an upper surface 78, and a lower surface 79.
  • An upper venturi assembly 80 has its entry port 81 on one side of the airfoil 75, while a lower venturi assembly 90 has its entry port 91 on the opposite side.
  • the venturi assembly 80 has an exit port 82, a throat 83, air nozzles 84, and a plenum chamber 85.
  • the lower venturi assembly 90 has an exit port 92, a throat 93, air nozzles 94, and a plenum chamber 95.
  • a modified structure of a venturi assembly 100 is illustrated in Figure 11 in a horizontal fixed wing.
  • the venturi assembly 100 has an entry port 101, an exit port 102, and a throat 103.
  • a plurality of air nozzles 104 are in communication with a plenum chamber 105.
  • Deflector vanes 107 are pivoted, respectively, on hinges 108. The deflector vanes 108 can be actuated together in coordinated travel to vary the direction of the air flow exiting the venturi assembly 100.
  • applicant's novel airfoil construction could be used on a water vehicle to aid in lifting its hull partially or entirely out of the water. It would also provide forward thrust.
  • FIG. 12-14 another airfoil embodying the present invention is indicated generally by the reference numeral 110.
  • the airfoil 110 is the fixed wing of an aircraft (not shown) .
  • the airfoil of the present invention will be described with reference to a fixed wing aircraft, it can be equally employed in other types of vehicles and apparatus.
  • airfoils embodying the present invention can be used to form the tail rudders of aircraft, the rotating blades of helicopters, or the blades of gas turbines or air compressors. -17-
  • the airfoil 110 is defined by a leading edge 112, a trailing surface 114, an upper surface 116, and a lower surface 118.
  • the airfoil 110 defines a chord line C, and is positioned in a typical flight orientation. 5 Thus, the chord line C is oriented at an angle A with respect to the horizontal axis X.
  • the airfoil 110 has a venturi-shaped aperture 120 extending therethrough.
  • the venturi-shaped aperture 120 is a venturi-shaped aperture 120 extending therethrough.
  • the venturi-shaped aperture 120 is defined by an inlet port 122 extending through the upper surface 116, and an exit port 124 extending through the lower surface 118. As shown in Figure 12, the inlet port 122 is located
  • the exit port 124 is located within about the aft quarter section of the lower surface 118.
  • the venturi-shaped aperture 120 is further defined by a 20 forward and an aft wall extending between the inlet port 122 and the exit port 124. Each wall is defined by a narrow throat portion 128, a converging portion 126 converging inwardly from the inlet port 122 and
  • the diverging portions 130 diverge outwardly from the throat portion 128 and terminate on the exit port 124.
  • the throat portions 128 thus define a narrow throat located about halfway between the inlet port 122 and exit port 124. As shown in Figure 12, the
  • the 30 throat has a cross-sectional flow area less than that of either the inlet or exit ports.
  • the geometrical configurations of the converging portions 126 and diverging portions 130 can be shaped as desired to optimize the flow characteristics of the air
  • the venturi-shaped aperture 120 defines a longitudinal axis Z, oriented at angle B with respect to the vertical axis Y.
  • the angle B is determined so that the exit port 124 is positioned sufficiently aft of the inlet port 122, to cause the air to be discharged at an angle with respect to the under surface of the airfoil to prevent separation.
  • the angle B is preferably within the range of about 20 to 80 degree .
  • the airfoil 110 further defines a plurality of suction ports 132 extending through the converging portion 126 of the forward wall below the entrance port 122.
  • the suction ports 132 are spaced apart from each other across the converging portion 126 and in the spanwise direction of the airfoil.
  • a first plenum chamber 134 is formed within the airfoil 110 adjacent to the suction ports 132.
  • the first plenum chamber 134 is coupled to the suction ports 132 and to one end of a suction line 136 (indicated in phantom) .
  • the other end of the suction line 136 is coupled to the entrance port of a fan 138 (illustrated schematically) .
  • the fan 138 is remotely mounted on an aircraft (not shown) away from the airfoil 110 in a location where it can be conveniently packaged.
  • the outlet port of the fan 138 is coupled to a discharge line 140 (indicated in phantom) .
  • An auxiliary power unit 139 (illustrated schematically) is coupled through a valve 141 to the discharge line 140.
  • the auxiliary power unit 139 is preferably the compressor bleed line of the gas turbine engine (not shown) on the aircraft, but might otherwise be an additional fan or compressor.
  • the valve 141 can thus be opened to direct additional pressurized gas into the discharge line 140. However, the valve 141 can be closed if the additional pressurized gas is not needed.
  • the discharge line 140 is in turn coupled to two second plenum chambers 142 and a third plenum chamber 144.
  • the third plenum chamber 144 is formed within the airfoil 110 adjacent to the trailing edge 114, and extends in the spanwise direction of the airfoil.
  • Each second plenum chamber 142 is formed within the airfoil 110 adjacent to a respective throat portion 128, and extends in the spanwise direction of the airfoil.
  • a plurality of first injection ports 146 extend through the respective throat portions 128, and are each coupled to a respective second plenum chamber 142.
  • the first injection ports 146 are spaced apart from each other in the spanwise direction of the airfoil.
  • the first injection ports 146 are oriented so that the air flowing therethrough is directed at an angle of about 20° with respect to a line extending tangential to the adjacent diverging portion 130.
  • the pressurized air flowing into the two second plenum chambers 142 is injected through the first injection ports 146 into the throat of the venturi-shaped aperture 120.
  • the first injection ports 146 and the venturi- shaped aperture 120 thus act as an ejector.
  • the high velocity injected air entrains a larger amount of free stream air by momentum and energy transfer.
  • the airflow through the first injection ports 146 thus energizes the stream of air flowing through the venturi-shaped aperture 120.
  • the air stream is in turn discharged through the diverging portions 130 and the exit port 124, as indicated by the arrows in Figure 12.
  • the air drawn into the suction ports 132 also causes additional air to be entrained into the venturi-shaped aperture 120.
  • the air flowing through the first injection ports 146 further contributes to entraining air. Therefore, the total quantity of air discharged through the venturi-shaped aperture 120 is greater than the amount that would be realized from either the suction ports 132 or the first injection ports 146 operating alone.
  • the combined action of the suction ports 132, the fan 1 ' 38 (and the auxiliary power unit 139) , and the first injection ports 146 overcomes many of the inefficiencies of simply using an ejector as a pump alone.
  • the slanted orientation of the venturi-shaped aperture 120, and thus the location of the exit port 124 aft of the inlet port 122 provides a relatively long ejector mixing section defined by the diverging portions 130.
  • the elongated configuration of the diverging portions 130 thus improves the performance of the first injection ports 146.
  • the aft edge of the exit port 124 is contoured to cause the discharged air to flow smoothly across the under surface of the airfoil to avoid separation.
  • the trailing surface 114 is defined by a trailing edge flap 148 pivotally mounted on the aft edge of the airfoil 110.
  • the trailing edge flap 148 is coupled to a hydraulic control system (not shown) .
  • a hydraulic control system not shown
  • other types of control systems known to those skilled in the art can equally be used.
  • the orientation of the flap 148 is adjusted to control the direction of airflow over and under the aft section of the airfoil.
  • the airfoil 110 further defines a second injection port 150, extending through the upper surface 116 above the trailing edge flap 148.
  • the second injection port 150 extends along the upper surface 116 in the spanwise direction of the airfoil.
  • the second injection port 150 is coupled to the third plenum chamber 144 to receive pressurized air therefrom.
  • the second injection port 150 is oriented to direct a high velocity jet of air substantially tangential to the upper surface of the flap 148, as indicated by the arrow in Figure 12.
  • the second injection port 150 and trailing edge flap 148 thus act as a blown flap.
  • the high velocity air is injected into the boundary layer on the upper surface of the flap 148.
  • the high velocity air delays flow separation over the upper surface 116 and the upper surface of the flap 148 and, as a result, provides additional lift through circulation control.
  • the trailing edge flap 148 can be rotated into a downward position as illustrated in Figure 13, to provide additional lift during take-off or landing.
  • the injection port 150 and trailing edge flap 148, or blown flap thus delay flow separation aft of the inlet port 122 and over the upper surface of the trailing edge flap 148. Therefore, the blown flap is useful even when the trailing edge flap 148 is in the cruise position, because the flow aft of the inlet port 122 is prone to separate. -22-
  • the trailing edge flap 148 is shown rotated so as to close the exit port 124. In this position, the blown flap becomes a Coanda jet.
  • the trailing surface 114 of the airfoil is defined by a substantially semi-circular surface, and the high velocity jet of air passing through the injection port 150 is directed over that surface, as indicated by the arrow in Figure 14.
  • the high speed jet energizes the boundary layer of the trailing surface 114.
  • the flow on the upper side of the trailing surface remains substantially attached, and the rear stagnation point is moved approximately under the rounded trailing surface. This unsymmetrical flow pattern increases the circulation and, hence, the lift of the airfoil.
  • FIG. 15 another airfoil embodying the present invention is indicated generally by the reference numeral 210.
  • the airfoil 210 is defined by a leading edge 212, a trailing surface 214, an upper surface 216, and a lower surface 218.
  • the airfoil 210 is the fixed -23 - wing of an aircraft (not shown) . It should be noted, however, that the airfoil 210, like the airfoil 110 described above, can be equally used in other types of vehicles.
  • the airfoil 210 defines a venturi 220 formed therethrough and extending in the spanwise direction of the airfoil.
  • the venturi 220 is defined by an entrance port 222 extending through the upper surface 216, and an exit port 224 extending through the airfoil below the trailing surface 214.
  • the venturi 220 is further defined by a front wall and an aft wall extending between the entrance port 222 and exit port 224.
  • Each wall is defined by a converging portion 226, converging inwardly and terminating on a throat portion 228, and a diverging portion 230.
  • the diverging portions 230 diverge outwardly from the respective throat portions 228 and terminate on the exit port 224.
  • the diverging portions 230 thus define a mixing chamber 232 extending between the throat portions 228 and the exit port 224.
  • the mixing chamber 232 is substantially elongated, and its longitudinal axis is oriented at a slight angle with respect to the chord line C, preferably within the range of about 0° to 30°.
  • the trailing surface 214 is defined by a trailing edge flap 234 pivotally mounted to the aft edge of the airfoil and extending in its spanwise direction.
  • the trailing edge flap 234 defines a channel 235 extending from the exit port 224 through the trailing edge of the flap, and extending in the spanwise direction of the airfoil.
  • the channel 235 is in fluid communication with the exit port 224, and thus permits the airflow through the venturi 220 to pass therethrough.
  • the trailing surface 214 and channel 235 thus act as a mechanical flap as well as a jet flap.
  • the high velocity airflow generated through the venturi 220 passes through the trailing edge 214 and, hence, provides lift through circulation control and the directional thrust of the airflow.
  • the trailing edge flap 234 is coupled preferably to a hydraulic control system (not shown) . However, other types of control systems known to those skilled in the art can equally be used. The position of the trailing edge flap 234 is adjusted to control the direction of the airflow through and over the trailing surface 214.
  • the converging portions 226 define several suction ports 236 extending therethrough. There are a plurality of suction ports 236 spaced apart from each other across the converging portion 226 of the front wall, and in the spanwise direction of the airfoil on both the front and aft walls.
  • the suction ports 236 are each coupled to one of two respective first plenum chambers 238.
  • Each first plenum chamber 238 is defined within the airfoil 210 adjacent to a respective converging portion 226, and extends in the spanwise direction of the airfoil.
  • the first plenum chambers 238 are each in turn coupled to a suction line 240 (indicated in phantom) .
  • the other end of the suction line 240 is coupled to the entrance port of a compressor 242 (illustrated schematically) .
  • the compressor 242 is located in a remote section of the aircraft (not shown) where it can be conveniently mounted.
  • An auxiliary pressure line 243 (indicated in phantom) is coupled on one end to the outlet port of the compressor 242, and coupled on the other end to the exit port of an auxiliary power unit 245 (illustrated schematically) .
  • the auxiliary power unit 245 is an additional source of pressurized gas, preferably the compressor bleed duct of a gas turbine engine (not shown) on the aircraft.
  • the auxiliary power unit 245 can otherwise be, for example, an additional fan or compressor. An additional amount of pressurized gas from the auxiliary power unit 245 is therefore pumped through the exit port of the compressor 242 to enhance the effect of the venturi 220.
  • the exit port of the compressor 242 is coupled to a first pressure line 244 and a second pressure line 246 (both indicated in phantom) .
  • the first pressure line 244 is in turn coupled to two second plenum chambers 248.
  • Each second plenum chamber 248 is defined within the airfoil 210 adjacent to a respective throat portion 228, and extends in the spanwise direction of the airfoil.
  • the airfoil 210 further defines several first injection ports 250 extending through the throat portions 228, and spaced apart from each other in the spanwise direction of the airfoil.
  • Each first injection port 250 is coupled to a respective second plenum chamber 248 to receive pressurized gas therefrom.
  • Each first injection port 250 is oriented so that the air flowing therethrough is directed at an angle of about 20* with respect to a line extending tangential to the adjacent diverging portion 230.
  • the injection ports 250 and throat portions 228 are positioned to act as an ejector in the same way as the first injection ports 146 and throat portions 128 described above.
  • the compressor 242 sucks air through the suction ports 236 into the two first plenum chambers 238.
  • the air in the first plenum chambers 238 flows through the compressor 242, is compressed, and then mixed with the additional pressurized air or gas from the auxiliary power unit 245 in the outlet port of the compressor.
  • the pressurized air then flows into the first and second pressure lines 244 and 246, respectively.
  • the air in the first pressure line 244 flows into the second plenum chambers 248, through the first injection ports 250, and into the venturi 220, thus generating a relatively high mass airflow therethrough.
  • the airfoil 210 further defines a third plenum chamber 252 located adjacent to the trailing surface 214 and extending in its spanwise direction.
  • a second injection port 254 is formed through the upper surface 216 above the trailing edge flap 234 and extends in the spanwise direction of the airfoil.
  • the second injection port 254 is coupled to the third plenum chamber 252 to receive pressurized gas therefrom.
  • the third plenum chamber 252 is in turn coupled to the other end of the second pressure line 246. Pressurized air thus flows into the third plenum chamber 252 and through the second injection port 254.
  • the second injection port 254 is positioned so that a high velocity jet of air is directed tangentially to the trailing surface 214, as indicated by the arrow in Figure 15.
  • the second injection port 254 and trailing edge flap 234 thus act as a blown flap in the same way as the second injection port 150 and flap 148 described above.
  • a lift is induced by the circulation control caused by sucking air in over the upper surface 216 and discharging air through the trailing edge flap 234.
  • the high velocity jet discharged through the second injection port 254 across the trailing surface 214, or blown flap, further contributes to circulation control and, hence, an increase in lift.
  • a lift is also induced by the momentum of the discharging jet from the venturi 220 through the exit port 224, and thus the trailing edge flap 234.
  • the mixing channel 232 is oriented at only a slight angle relative to the airfoil chord line C, the exiting jet of the venturi 220 can be oriented at about the same angle, depending upon the orientation of the flap 234, as indicated by the arrow in Figure 15.
  • the venturi 220 has a relatively long mixing chamber 232, which tends to maximize its efficiency.
  • the exit port 224 of the venturi 220 is located within the trailing surface 214, and is not located through the lower surface 218 of the airfoil, air separation on the lower surface aft of the venturi , s discharge port is prevented.
  • the airfoil of the present invention thus emulates the performance of a fan-in-wing or a ducted fan-in-wing with a jet flap, without many of the disadvantages of those devices.
  • the trailing surface 214, and thus the ducting for the jet flap can be oriented in various positions to deflect the high velocity jet from a horizontal to a more vertical position.
  • the venturi 220 provides a large mass airflow at a relatively low velocity, so that it is an efficient propulsion device.
  • the airfoil of the present invention is therefore useful for both take-off and landing, as well as cruise operation.
  • the entrance port and exit port of the venturi 220 do not have to be circular, as is the case with the fan-in-wing or ducted fan-in-wing, the airfoil of the present invention can be more conveniently packaged on an aircraft.
  • FIG. 16 another airfoil embodying the present invention is indicated generally by the reference numeral 310.
  • the airfoil 310 defines an upper surface -28-
  • the airfoil 310 further defines a venturi-shaped aperture 318 extending therethrough.
  • the venturi-shaped aperture 318 is defined by an inlet port 320 and an exit port 322.
  • the venturi-shaped aperture 318 is further defined by a front wall and an aft wall extending between the inlet port 320 and exit port 322.
  • Each wall is defined by a converging portion 324, converging inwardly toward a throat portion 326, and a diverging portion 328, diverging outwardly toward the exit port 322.
  • the throat portions 326 define a throat having a cross-sectional area less than that of either the inlet port 320 or exit port 322.
  • the airfoil 310 further defines a plurality of injection ports 330 extending through the throat portions 326.
  • the injection ports 330 are spaced apart from each other in the spanwise direction of the airfoil.
  • the cross- sectional area of each injection port 330 is dimensioned to be substantially less than the cross-sectional area of the throat.
  • Two first plenum chambers 332 are defined within the airfoil 310, each being located adjacent to a respective throat portion 326.
  • Each first plenum chamber 332 is coupled in fluid communication with the injection ports 330 extending through the adjacent throat portion 326.
  • the first plenum chambers 332 are in turn coupled to a source of pressurized gas (not shown) .
  • the airfoil 310 further defines a scoop 342 extending through the upper surface 312 in front of the inlet port 320.
  • the scoop 342 is provided to direct the flow of air over the upper surface 312 into the inlet port 320.
  • pressurized gas flows through the injection ports 330, and into the -29- throat of the venturi-shaped aperture 318.
  • Each injection port 330 is oriented so that the stream of air passing therethrough is directed approximately 20° with respect to a line extending tangential to the adjacent diverging portion 328.
  • the injection ports 330 and the throat 326 thus act as an ejector.
  • the high velocity injected air entrains an additional amount of free steam air by momentum and energy transfer.
  • the airflow through the injection ports 330 thus energizes the stream of air flowing through the venturi-shaped aperture 318.
  • the stream of air is in turn discharged through the exit port 322, as indicated by the arrows in Figure 16.
  • the aft edge of the exit port 322 is defined by a radius of curvature R.
  • the radius of curvature R is dimensioned to prevent, or at least delay separation of the air discharged through the exit port 322 from the trailing edge 316 of the airfoil.
  • the air flowing across the aft edge of the exit port 322 thus emulates a Coanda jet and further increases lift by circulation control.
  • the exit port 322 can be shaped as desired to achieve different performance with the airfoil 310.
  • the forward edge of the exit port 322 can be formed into a semi-circular surface, as indicated in phantom in Figure 16.
  • the aft edge of the exit port 322 can be formed into a sharp corner, as also indicated in phantom in Figure 16.
  • the forward edge of the exit port 322 acts as a Coanda jet.
  • the air discharged over the forward edge tends to flow downwardly, as indicated by the arrows in phantom in Figure 16, to increase the lift on the airfoil.
  • the downward flow of air can be used to generate a drag sufficient to slow the aircraft during landing.
  • the airfoil 320 further defines an injection slot 338 formed through the upper surface 312 aft of the inlet port 320, and extending in the spanwise direction of the airfoil.
  • a second plenum chamber 340 is defined within the airfoil 310 adjacent to the injection slot 338 and is in fluid communication therewith.
  • the second plenum chamber 340 is coupled to a source of pressurized gas (not shown) .
  • the pressurized gas flows into the second plenum chamber 340 and through the injection slot 338.
  • the injection slot 338 is oriented so that the stream of pressurized gas flowing therethrough is directed tangentially to the upper surface 312, as indicated by the arrow in Figure 16.
  • the injection slot 338 and trailing edge 316 thus act as a blown flap.
  • the jet of air is injected into the boundary layer over the trailing edge 316 to delay flow separation aft of the inlet port 320 and, therefore, increase lift by circulation control.
  • FIG 17 two airfoils 310 of the present invention are shown employed as the fixed wings of an aircraft, indicated generally as 344.
  • Each wing 310 has incorporated therein five venturi-shaped apertures 318 spaced apart from each other in the spanwise direction of the wing.
  • the aircraft 344 comprises a jet engine 346, and a compressor 348 (illustrated schematically) mounted to its fuselage 349.
  • a first pressure line 350 is coupled to the outlet port of the compressor 348 and extends in the spanwise direction of each wing 310.
  • Two third pressure lines 351 are each coupled on one end to the -31- compressor bleed duct of the gas turbine engine 346, to receive a portion of the pressurized compressor gases flowing therefrom. The other ends of the third pressure lines 351 are coupled to the first pressure line 350.
  • the first pressure line 350 is in turn coupled to a plurality of third pressure lines 352.
  • Each third pressure line 352 is in turn coupled to the first plenum chambers 332 associated with a respective venturi-shaped aperture 318.
  • Each third pressure line 352 is also coupled to the second plenum chamber 340 of the respective wing 310.
  • the pressurized gases flow through the pressure line 350 and into the first plenum chambers 332 and second plenum chamber 340 of each wing 310.
  • an airfoil indicated generally by the reference numeral 510 is employed as a typical blade in a gas turbine (not shown) .
  • the airfoil 510 is mounted on one end to a rotating, hollow shaft 512 of the gas turbine.
  • the airfoil 510 has a geometrical surface configuration typical of gas turbine blades.
  • the airfoil 510 defines a leading edge 514, a trailing edge 516, a lower surface 518, and an upper surface 520.
  • the shaft 512 rotates in a counterclockwise direction, as indicated by the arrow in Figure 18. Therefore, the lower surface 518 is on the lower velocity, higher pressure side, and the upper surface 520 is on the higher velocity, lower pressure side of the airfoil 510.
  • the airfoil 510 is hollow and thus defines an air chamber 522 therein.
  • the airfoil 510 further includes a hollow tube 524 extending through the airfoil in its spanwise direction, as shown in phantom in Figure 18.
  • the tube 524 is mounted on one end to an inlet port 526 extending through the fixed end of the airfoil, and is mounted on the other end to the inside surface of the free end of the airfoil.
  • the tube 524 is located within about the forward quarter section of the airfoil 510 near the leading edge 514, as shown in Figure 19.
  • the inlet port 526 is in turn coupled in fluid communication with a port 528 extending through the outer wall of the shaft 512.
  • the tube 524 further defines a plurality of injection nozzles 530 extending through the front side of the tube and facing the inside surface of the leading edge 514.
  • the injection nozzles 530 are spaced apart from each other in the spanwise direction of the tube 524.
  • the airfoil 510 further defines an injection slot 532 extending through the upper surface 520 and located in about the aft quarter section of the airfoil.
  • the injection slot 532 is oriented so that the air flowing therethrough is directed substantially tangential to the upper surface 520 toward the trailing edge 516. The air is thus injected into the boundary layer to delay flow separation over the upper surface 520 and trailing edge 516 and, hence, to increase lift through circulation control.
  • the pressurized gas generated by a compressor (not shown) driven by the turbine is directed through the hollow shaft 512.
  • the pressurized gas flows through the port 528, into the inlet port 526, and thus into the tube 524.
  • the pressurized gas in turn flows through the injection nozzles 530 and across the inside surface of the leading edge 514, as indicated by the arrows in Figure 19.
  • the pressurized gas is cooler than the metal surfaces of the airfoil 510. Therefore, the lower temperature gas flowing across the inside surface of the leading edge 514 tends to cool the leading edge and, as a result, increase in temperature.
  • the higher temperature pressurized gas then flows through the air chamber 522 and is discharged through the injection slot 532, as indicated by the arrow in Figure 19.
  • the pressurized gas flows substantially tangential to the upper surface 520 and across the trailing edge 516. Accordingly, the pressurized gas both cools the leading edge 514 and increases the lift on the airfoil by circulation control.
  • FIGs 20 through 23 various embodiments of the airfoil 510 are illustrated, wherein like reference numerals are used to indicate like elements.
  • the injection slot 532 extends through the trailing edge 516. Therefore, the higher temperature pressurized gas flowing through the air chamber 522 is discharged through the trailing edge 516.
  • the injection slot 532 thus emulates a jet flap; the reaction force of the pressurized gas discharged through the trailing edge increases the lift on the airfoil.
  • the airfoil 510 further includes a slot 534 formed therethrough and extending in its spanwise direction.
  • the slot 534 is defined by an entrance port 536 extending through the lower surface 518, and an exit port 538 extending through the upper surface 520.
  • the slot 534 is further defined by a wall 540 extending between the entrance port 536 and the exit port 538.
  • the exit port 538 is located aft of the entrance port 536. Therefore, the longitudinal axis of the slot 534 is oriented at an angle D with respect to a plane of the upper surface 520.
  • the angle D is preferably within the range of about 0 to 30 degrees.
  • the injection slot 532 extends through the upper surface 520 immediately in front of the exit port 538.
  • the injection slot 532 is oriented so that the pressurized gas discharged therethrough is directed substantially tangential to the upper surface 520, and across the trailing edge 516.
  • the exit port 538 is oriented so that the air flowing therethrough flows substantially tangential to the upper surface 520 toward the trailing edge 516.
  • the high velocity jet discharged through the injection port 532 energizes the boundary layer over the exit port 538 and the trailing edge 516, and further entrains some additional air through the slot 534.
  • the slot 534 and the injection slot 532 thus increase the lift on the airfoil by circulation control. As a result, the lift on the airfoil 510 is increased and, therefore, the efficiency of the gas turbine is increased.
  • the airfoil 510 includes a venturi-shaped aperture 542 formed therethrough and extending in the spanwise direction of the airfoil.
  • the venturi-shaped aperture 542 is defined by an inlet port 544 and an exit port 546.
  • the venturi-shaped aperture 542 is further defined by a front wall and an aft wall extending -35- between the inlet port 544 and the exit port 546.
  • Each wall is defined by a converging portion 548 that terminates on a throat portion 550, and a diverging portion 552.
  • Each diverging portion 552 diverges outwardly from the respective throat portion 550 and terminates on the exit port 546.
  • the cross-sectional area between the throat portions 550 is less than that of either the inlet port 544 or the exit port 546.
  • the exit port 546 is located aft of the inlet port 544, so that the longitudinal axis of the venturi-shaped aperture 542 is oriented at an angle E with respect to a vertical axis Y.
  • the angle E is determined to avoid, or at least delay separation of the air discharged through the exit port 546 from the under surface 518 of the airfoil.
  • the airfoil 510 further defines a plurality of injection ports 554 extending through the throat portion 550 of the front wall.
  • the injection ports 554 are spaced apart from each other in the spanwise direction of the airfoil.
  • Each injection port 554 is oriented so that the air discharged therethrough flows downwardly through the exit port 546.
  • the warmer pressurized gas flowing through the air chamber 522 is discharged through the injection ports 554.
  • the pressurized air in turn flows down through the exit port 546.
  • the air discharged through the exit port 546 further entrains additional air through the entrance port 544. Therefore, the venturi-shaped aperture 542 increases the lift of the airfoil by the reaction forces of the jet through the exit port 546 and by circulation control.
  • the airfoil 510 defines a substantially cylindrical surface 553 extending therethrough in its spanwise direction and surrounding the tube 524.
  • the air chamber 522 is thus defined between the tube 524 and the surface 553.
  • the airfoil 510 further defines a first injection port 554 extending through the upper surface 520 immediately above the tube 524.
  • Each first injection port 554 is coupled to the air chamber 522 by a first conduit 556, to receive pressurized gas therefrom.
  • the airfoil 510 further defines several second injection ports 558 extending through the upper surface 520.
  • the second injection ports 558 are located about halfway across the upper surface 520 and spaced apart from each other in the spanwise direction of the airfoil. Each second injection port 558 is coupled to the air chamber 522 by a second conduit 560, to receive pressurized gas therefrom.
  • the airfoil 510 further defines several third injection ports 562 extending through the upper surface 520 adjacent to the trailing edge 516. Each third injection port 562 is coupled to the air chamber 522 by a third conduit 564, to receive pressurized gas therefrom.
  • the first injection ports 554, second injection ports 558, and third injection ports 562 are oriented with respect to the upper surface 520, so that the pressurized gas flowing therethrough achieves maximum performance in obtaining the desired effect of the airfoil 510.
  • FIG. 24 and 25 another airfoil, indicated generally by the reference numeral 610, is employed as a typical blade in a gas turbine (not shown) .
  • the airfoil 610 is mounted on one end to a rotating, hollow shaft -37-
  • the airfoil 610 has a geometrical surface configuration typical of gas turbine blades.
  • the airfoil 610 defines a leading edge 614, a trailing edge 616, a lower surface 618, and an upper surface 620.
  • the shaft 612 rotates in a counterclockwise direction, as indicated by the arrow in Figure 24. Therefore, the lower surface 618 is on the lower velocity, higher pressure side, and the upper surface 620 is on the higher velocity, lower pressure side of the airfoil 610.
  • the airfoil 610 further includes a channel 622 defined by a substantially cylindrical wall 624 extending through the airfoil in its spanwise direction.
  • the channel 622 is further defined by an inlet port 626 extending through the fixed end of the airfoil, and a first exit port 628 extending through the lower surface 618 adjacent to the free end of the airfoil, as shown in Figure 24.
  • the channel 622 is located within about the forward quarter section of the airfoil 610 near the leading edge 614, as shown in Figure 25.
  • the inlet port 626 is in turn coupled in fluid communication with a port 630 extending through the outer wall of the shaft 612.
  • the airfoil 610 further defines several first injection ports 632 extending through the upper surface 620 and in fluid communication with the channel 622, to receive pressurized gas therefrom.
  • the first injection ports 632 are located immediately above the channel 622 and are spaced part from each other in the spanwise direction of the airfoil.
  • the airfoil 610 further defines several second injection ports 634 formed through the upper surface 620 and a fluid communication with the channel 622, to receive pressurized gas therefrom.
  • the second injection ports 634 are located -38- in about the aft half section of the upper surface 620, and spaced apart from each other in the spanwise direction of the airfoil.
  • the airfoil 610 further defines several apertures 636 extending therethrough in about the forward half section of the airfoil, on the aft side of the channel 622.
  • the apertures 636 are spaced apart from each other in the spanwise direction of the airfoil.
  • Each aperture 636 is defined by an inlet port 638 formed through the lower surface 618, and second exit port 640 formed through the upper surface 620.
  • Each second exit port 640 is located aft of the respective inlet port 638.
  • the first exit port 628, second exit ports 640, first injection ports 632, and second injection ports 634 are oriented with respect to the upper surface 620 to achieve maximum performance for the desired effect of the airfoil 610.
  • pressurized gas generated by a compressor (not shown) driven by the turbine is directed through the hollow shaft 612.
  • the pressurized gas flows into the port 630 and channel 622, and through the outlet port 628 of the airfoil, as indicated by the arrow in Figure 24.
  • the pressurized gas also flows through the first injection ports 632 and second injection ports 634 into the low pressure side of the airfoil.
  • the first injection ports 632 and second injection ports 634 can be oriented to direct the gas flowing therethrough substantially tangential to, or at a slight angle with respect to the upper surface 620.
  • the pressurized gas would thus energize the boundary layer on the upper surface 620 and, hence, increase lift by circulation control.
  • the gas flowing through the apertures 636 can be discharged to energize the boundary layer on the upper surface 620 and, therefore, further increase lift by circulation control.
  • the density of the air decreases and, as a result, the airflow generated over the blades of a gas turbine usually becomes more laminar.
  • a laminar flow does not attach as easily to the surfaces of the turbine blades, as compared to the more turbulent flow at lower atmospheric levels. The laminar flow is thus prone to separate from the surfaces of the turbine blades and, as a result, can cause the gas turbine to stall.
  • the airfoil 610 alleviates this problem by injecting the pressurized gas through the first injection ports 632 and second injection ports 634 into the low pressure side of the airfoil.
  • the pressurized gas increases the turbulence adjacent to the boundary layer of the airfoil. Therefore, under low density, high atmospheric conditions, separation is less likely to occur.
  • the apertures 636 further contribute to generating - turbulence by permitting air to flow from the high pressure side into the low pressure side of the airfoil.

Abstract

Un profil d'aile est défini par une surface supérieure, une surface inférieure, ainsi qu'une ouverture en forme de venturi formée dans ces dernières. L'ouverture (120) en forme de venturi s'étend dans le sens de l'envergure du profil d'aile, et se situe dans la demi-section arrière du profil d'aile. L'ouverture (120) en forme de venturi est définie par un orifice d'admission (122) s'étendant dans la surface supérieure, et par un orifice de sortie (124) s'étendant dans la surface inférieure. Le profil d'aile définit également une pluralité d'orifices d'aspiration (132) s'étendant dans la partie convergente (126) de la paroi avant. Une pluralité d'orifices d'injection s'étend dans la partie de gorge (128). La soufflante (138) aspire de l'air par l'intermédiaire des orifices d'aspiration (132), comprime l'air, puis injecte l'air par l'intermédiaire des orifices d'injection (146) dans l'ouverture (120) en forme de venturi. Ainsi, l'ouverture (120) en forme de venturi augmente la sustentation sur le profil d'aile par les forces de réaction du jet déchargées par l'intermédiaire de l'orifice de sortie (124), et par régulation de la circulation.
PCT/US1990/007687 1989-12-29 1990-12-28 Profil d'aile ameliore par un venturi WO1991009776A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US45816489A 1989-12-29 1989-12-29
US458,164 1989-12-29

Publications (1)

Publication Number Publication Date
WO1991009776A1 true WO1991009776A1 (fr) 1991-07-11

Family

ID=23819636

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1990/007687 WO1991009776A1 (fr) 1989-12-29 1990-12-28 Profil d'aile ameliore par un venturi

Country Status (1)

Country Link
WO (1) WO1991009776A1 (fr)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1118747A2 (fr) * 2000-01-22 2001-07-25 Rolls-Royce Plc Aube pour une turbomachine axiale
WO2009004499A1 (fr) 2007-06-29 2009-01-08 Alenia Aeronautica S.P.A. Procédé pour augmenter la portance de surfaces aérodynamiques et pour réduire la traînée
WO2010115656A1 (fr) * 2009-04-06 2010-10-14 Rolls-Royce Plc Dispositif de commande d'écoulement destiné à commander un écoulement de fluide sur une surface
FR2974563A1 (fr) * 2011-04-28 2012-11-02 Airbus Operations Sas Profil aerodynamique reduisant le deficit de vitesse dans son sillage
EP2597038A3 (fr) * 2011-11-24 2015-11-25 Rolls-Royce plc Aéronef
JP2021526094A (ja) * 2018-05-29 2021-09-30 ジェトップテラ，インコーポレイテッド 境界取り込み流体推進要素による機体の合理化

Citations (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1829616A (en) * 1929-03-28 1931-10-27 Edward A Stalker Airplane
US1993419A (en) * 1931-08-19 1935-03-05 Edward A Stalker Aircraft
US2466466A (en) * 1945-11-01 1949-04-05 United Aircraft Corp Flap and jet device for airplane wings
US2585676A (en) * 1947-07-31 1952-02-12 Poisson-Quinton Philippe Aircraft wing and flap with boundary layer control
US2631794A (en) * 1947-07-22 1953-03-17 Douglas K Warner Airfoil nose flap arrangement
US3013744A (en) * 1960-03-11 1961-12-19 Gen Electric Vtol boundary layer control system
US3047208A (en) * 1956-09-13 1962-07-31 Sebac Nouvelle Sa Device for imparting movement to gases
US3406759A (en) * 1967-08-15 1968-10-22 Nutku Ata Controllable pitch propeller
US3507463A (en) * 1968-01-18 1970-04-21 William Donald Kuntz Thrust induced vortex lift arrangement for aircraft
US3574481A (en) * 1968-05-09 1971-04-13 James A Pyne Jr Variable area cooled airfoil construction for gas turbines
US3628880A (en) * 1969-12-01 1971-12-21 Gen Electric Vane assembly and temperature control arrangement
US3819134A (en) * 1972-11-30 1974-06-25 Rockwell International Corp Aircraft system lift ejector
EP0029145A2 (fr) * 1979-11-19 1981-05-27 Vianova Kunstharz Aktiengesellschaft Procédé de préparation d'émulsions aqueuses de résines alkydes séchant à l'air ou au traitement thermique
US4442986A (en) * 1982-08-30 1984-04-17 The United States Of America As Represented By The Secretary Of The Navy Leading edge augmentor wing-in-ground effect vehicle
WO1988010210A1 (fr) * 1987-06-25 1988-12-29 Willis Mark T Plan de sustentation ameliore par venturi

Patent Citations (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1829616A (en) * 1929-03-28 1931-10-27 Edward A Stalker Airplane
US1993419A (en) * 1931-08-19 1935-03-05 Edward A Stalker Aircraft
US2466466A (en) * 1945-11-01 1949-04-05 United Aircraft Corp Flap and jet device for airplane wings
US2631794A (en) * 1947-07-22 1953-03-17 Douglas K Warner Airfoil nose flap arrangement
US2585676A (en) * 1947-07-31 1952-02-12 Poisson-Quinton Philippe Aircraft wing and flap with boundary layer control
US3047208A (en) * 1956-09-13 1962-07-31 Sebac Nouvelle Sa Device for imparting movement to gases
US3013744A (en) * 1960-03-11 1961-12-19 Gen Electric Vtol boundary layer control system
US3406759A (en) * 1967-08-15 1968-10-22 Nutku Ata Controllable pitch propeller
US3507463A (en) * 1968-01-18 1970-04-21 William Donald Kuntz Thrust induced vortex lift arrangement for aircraft
US3574481A (en) * 1968-05-09 1971-04-13 James A Pyne Jr Variable area cooled airfoil construction for gas turbines
US3628880A (en) * 1969-12-01 1971-12-21 Gen Electric Vane assembly and temperature control arrangement
US3819134A (en) * 1972-11-30 1974-06-25 Rockwell International Corp Aircraft system lift ejector
EP0029145A2 (fr) * 1979-11-19 1981-05-27 Vianova Kunstharz Aktiengesellschaft Procédé de préparation d'émulsions aqueuses de résines alkydes séchant à l'air ou au traitement thermique
US4442986A (en) * 1982-08-30 1984-04-17 The United States Of America As Represented By The Secretary Of The Navy Leading edge augmentor wing-in-ground effect vehicle
WO1988010210A1 (fr) * 1987-06-25 1988-12-29 Willis Mark T Plan de sustentation ameliore par venturi

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1118747A2 (fr) * 2000-01-22 2001-07-25 Rolls-Royce Plc Aube pour une turbomachine axiale
EP1118747A3 (fr) * 2000-01-22 2003-01-08 Rolls-Royce Plc Aube pour une turbomachine axiale
WO2009004499A1 (fr) 2007-06-29 2009-01-08 Alenia Aeronautica S.P.A. Procédé pour augmenter la portance de surfaces aérodynamiques et pour réduire la traînée
WO2010115656A1 (fr) * 2009-04-06 2010-10-14 Rolls-Royce Plc Dispositif de commande d'écoulement destiné à commander un écoulement de fluide sur une surface
FR2974563A1 (fr) * 2011-04-28 2012-11-02 Airbus Operations Sas Profil aerodynamique reduisant le deficit de vitesse dans son sillage
US8596574B2 (en) 2011-04-28 2013-12-03 Airbus Operations S.A.S. Streamlined profile reducing the speed deficit in its wake
EP2597038A3 (fr) * 2011-11-24 2015-11-25 Rolls-Royce plc Aéronef
JP2021526094A (ja) * 2018-05-29 2021-09-30 ジェトップテラ，インコーポレイテッド 境界取り込み流体推進要素による機体の合理化
EP3802323A4 (fr) * 2018-05-29 2022-03-02 Jetoptera, Inc. Fuselage aérodynamique avec éléments de propulsion fluidiques à ingestion de limite

Similar Documents

Publication Publication Date Title
US5016837A (en) Venturi enhanced airfoil
EP3363732B1 (fr) Configurations d'éjecteur et de profil aérodynamique
EP1159533B1 (fr) Regulation de flux d'air centrifuge
US5407150A (en) Thrust unit for VTOL aircraft
US7100875B2 (en) Apparatus and method for the control of trailing wake flows
US2841344A (en) Boundary layer control
US2408788A (en) Airfoil
US20100127129A1 (en) High performance airfoil with co-flow jet flow control
US3051413A (en) Vtol aircraft
US3317162A (en) Aircraft wing with internal air passages for increased lift
US6755374B1 (en) Anti-Torque and yaw-control system for a rotary-wing aircraft
US4641799A (en) Arrangement for controlling the air flow over aerodynamic profiles
US3085740A (en) End inlet jet pump for boundary layer control system
US3724784A (en) Wing with thrust augmentor
EP2597038A2 (fr) Aéronef
WO1991009776A1 (fr) Profil d'aile ameliore par un venturi
US3291420A (en) Wing structure and duct means for aircraft
US2961192A (en) Jet propelled aircraft
US3801048A (en) Method for reducing drag of vertical takeoff type aircraft
JP3212692B2 (ja) ローターブレードの境界層制御装置
US3237892A (en) Aircraft aerodynamic lifting member
CN111655580B (zh) 小翼喷射器构造
WO1988010210A1 (fr) Plan de sustentation ameliore par venturi
US3350036A (en) High-lift aircraft
GB2109755A (en) Propulsion system with thrust vectoring for a V/STOL airplane

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): CA JP KR NO SU

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FR GB GR IT LU NL SE

NENP Non-entry into the national phase

Ref country code: CA