WO1997017241A1 - Vehicule a effet de sol - Google Patents

Vehicule a effet de sol Download PDF

Info

Publication number
WO1997017241A1
WO1997017241A1 PCT/AU1996/000698 AU9600698W WO9717241A1 WO 1997017241 A1 WO1997017241 A1 WO 1997017241A1 AU 9600698 W AU9600698 W AU 9600698W WO 9717241 A1 WO9717241 A1 WO 9717241A1
Authority
WO
WIPO (PCT)
Prior art keywords
wing
fuselage
vehicle
angle
attack
Prior art date
Application number
PCT/AU1996/000698
Other languages
English (en)
Inventor
Michael John Leslie
Original Assignee
Sea Wing International Pty. Ltd.
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 Sea Wing International Pty. Ltd. filed Critical Sea Wing International Pty. Ltd.
Priority to NZ320036A priority Critical patent/NZ320036A/en
Priority to AU72697/96A priority patent/AU716801B2/en
Priority to EP96934221A priority patent/EP0859715A4/fr
Publication of WO1997017241A1 publication Critical patent/WO1997017241A1/fr

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60V—AIR-CUSHION VEHICLES
    • B60V1/00—Air-cushion
    • B60V1/08—Air-cushion wherein the cushion is created during forward movement of the vehicle by ram effect

Definitions

  • This invention relates to an improved vehicle which relies on the known ground effect to achieve more efficient operation of the vehicle.
  • Ground effect is achieved when an aerofoil is operating close to the ground plane, and in this position the lift generated by the aerofoil can be increased by up to 45% and the drag decreased by up to 70% as compared to the same aerofoil operating in free flight away from the ground plane.
  • This increase in efficiency is achieved in two ways. Firstly the proximity of the ground plane suppresses the usual "trailing edge vortices" formed behind the wing tips, and secondly, the down wash off the top of the wing is restricted. This down wash is normally responsible for creating considerable "induced drag” when it mixes and eddies with the air that has passed under the wing. In ground effect, the air that has passed under the wing is more compressed and is generally less turbulent than when the wing is in free flight.
  • the Lippisch reverse delta plan form craft known as the X-114, an example of which is described in US 3,190,582.
  • the wings extend slightly downwardly from the fuselage to the wing tips which terminate in upwardly and outwardly extending winglets.
  • the leading edge of the wing is generally at right angles to the fuselage.
  • the chord section of the wing varies from the root chord to the wingtip chord, the angle of attack of the wing is constant along is length.
  • This craft is designed to operate either in the ground effect plane or in free flight, and thus the craft is classified as an aeroplane.
  • a still further object of the invention is to provide a ground effect vehicle which is limited to ground effect flight, and thus cannot partake of free flight out of the ground effect area.
  • a vehicle capable of operation above ground or water in the ground effect area but not in free flight, said vehicle comprising a fuselage, wings, tail assembly with elevator and rudder, propulsion means, and a hull for operation in water, wherein said wings extend downwardly from each side of the fuselage and each being substantially triangular in plan and terminate in winglets at the wing tip, the leading edge of each wing being in plan at right angles to the fuselage, the root rib of each wing extending from the leading edge of the respective wing to the rear of the fuselage, each wing having in front elevation a compound downwardly curved wing section terminating in said upstanding winglets, the angle of attack of each wing increasing from the root area to a maximum along the wing and then decreasing towards the wing tip.
  • the maximum angle of attack is such that at higher speeds stagnation is promoted under the wing to defeat and counteract some of the lift on top of the wing thus preventing free flight.
  • the wing root is at the upper portion of the fuselage and the wing tip at a level near the bottom of the fuselage.
  • FIG. 1 is a perspective view of one form of craft embodying the invention
  • Figure 2 is a plan view of the craft of Figure 1 ,
  • Figure 3 is a front elevation showing the curvature of the wings
  • Figure 4 is a sectional side view showing the profile of the wing from wing root to wing tip.
  • the ground effect craft comprises a fuselage with a hull 2 and undercarriage 3.
  • the undercarriage will be retracted into the hull for operation on water, the undercarriage only being extended when it is required to beach the craft or run it onto a ramp or into a hanger for maintenance.
  • a tail assembly 4 and wings 5 attached to the fuselage at the upper portion of the fuselage.
  • Each wing 5 extends at its root area from the leading edge 6 to adjacent the rear of the fuselage 1 as shown in Figs 1 , 2 and 4 with the trailing edge 7 extending from the wing tip 8 to the rear of the fuselage 1.
  • Each wing in front elevation has a compound curved shape, the wing curving downwardly from the leading edge at the root chord at the upper portion of the fuselage to the wing tip at a lower position adjacent to or on the same level as the hull 2.
  • the wing extends in a curve downwardly to the wing tip which is on or level with the lower portion of the fuselage.
  • each wing is a reverse delta in plan form, the leading edge being generally normal to the fuselage.
  • Figure 4 shows the wing section at various ribs, the chord length decreasing from the root rib 10 through ribs 11 , 12, 13, 14 to the tip rib 15, which thus results in the reverse delta plan form with the leading edge being generally normal to the fuselage.
  • the angle of attack of the wing varies throughout its length, from the root rib, increasing to a maximum at rib 13, and then decreasing again to the tip rib 15.
  • the wing has an angle of attack of 8° at the root, increasing to 14° and then decreasing to 8° at the tip.
  • Each wing has winglets 16 at the tip, the winglets extending upwardly at an angle and having adjustable ailerons 17. The winglets and ailerons reduce the wing tip vortex losses and provide banking and cross wind control to the craft.
  • each wing curves downwardly, thus having a negative anhedral, or anhedral.
  • the anhedral angle is not constant across the span of the wing, and gradually increases along the span of the wing to a maximum towards the wing tip.
  • This in combination of the reverse delta plan form of the wing creates a compound undersurface shape of the wing, resulting in efficient operation as later described.
  • the craft is powered by at least one engine mounted in the fuselage and driving ducted propellers or fans 21 mounted above the fuselage.
  • the tail assembly includes the conventional elevator 18 and rudders 19. However the tail assembly comprises two fins 20 inclined in a Vee formation supporting the stabiliser and elevator 18 at their top. Thus there are two rudders, one on each inclined fin 20.
  • the hull 2 is formed with two outboard portions 22 and 23 which extend rearwardly to breakaway 24. Between the outboard portions 22 and 23 the undersurface 25 of the hull slopes downwardly and rearwardly from the front edge 26 to a section 27 where the surface then slopes rearwardly and downwardly to the section 28 where it merges into the bottom-of the outboard portions 22 and 23.
  • the angle of attack In order to reduce the take off and landing runs to a minimum it is essential to have greatest wing lift at low air speeds, and in order to achieve lift at low air speeds, the angle of attack must be high. This is achieved by the wing of the present invention which has a varying angle of attack along its span, the higher angles of attack giving high lift at low air speeds, and the lower angles of attack providing greater lift at higher air speeds.
  • the wing sections having a greater angle of attack generate increased drag at higher speeds and they actually promote stagnation under the wing.
  • This pocket of stagnation in turn leaks air over the trailing edge, increases velocity components in the downwash air stream, and at high airspeeds ultimately defeats some of the lift on the top wing surface.
  • the increase in drag only becomes significant at airspeeds over 180 knots, and actually prevents the wing from ever achieving flight out of ground effect.
  • the wing has an effective fail safe design, for irrespective of the installed horsepower, the craft will not achieve free flight out of ground effect.
  • the compound wing profile of the present invention also provides an excellent Lift/Drag efficiency.
  • an efficiency of 20% of the wing span above the surface was considered good. It has been found that the aspect ration of the wing in a ground effect operation greatly influences the overall efficiency in terms of Lift/Drag. While the Lift/Drag efficiency of the present wing design is not high when flying at a height of 10% of the wing span, when flying at a height over 10% of the wing span, the positive effect of the under wing shape becomes significant. Thus when operating at 30% of wing span above the ground plane there is a Lift/Drag coefficient of 37. When flying 20% which is still acceptable.
  • the tail assembly by utilising the Vee tail arrangement provides that during a standard rudder turn, the Vee tail arrangement forces the vessels outboard wing to push down on the cushion under the wing to thus hold the wing down to avoid any air cushion losses normally encountered when making a banked turn. Such losses would reduce the craft's surface clearance. This however can result in a turn of large radius. This can be overcome by using the wing tip ailerons to bank the craft to a small degree, so that the cushion losses under the outboard wing are held to a minimum, and provided of course there is sufficient surface clearance.
  • the craft of the invention can be used as a passenger ferry, for cargo and freight transport and even for surveillance duties.
  • the craft is a quick mode of transport between islands and around coastal waters.
  • a ground effect craft which is efficient in operation, has a high weight to power ratio, and also a high Lift/Drag ratio, and although one form of the invention has been described in some detail, it is to be realised that the invention is not to be limited thereto, but can include variations and modifications falling with in the spirit and scope of the invention.

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  • Engineering & Computer Science (AREA)
  • Aviation & Aerospace Engineering (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Catching Or Destruction (AREA)
  • Toys (AREA)

Abstract

Cette invention concerne un véhicule à effet de sol, lequel possède un fuselage lui permettant de se déplacer sur l'eau, ainsi que des ailes (5) courbées vers le bas de chaque côté du fuselage. Vu de haut, les ailes sont triangulaires et leurs bords d'attaques sont à angle droit par rapport au fuselage. Vu de face, les ailes sont fixées en position haute sur le fuselage, et possèdent une courbe descendante complexe jusqu'à leurs extrémités situées au niveau du fond du fuselage. L'angle d'attaque de chaque aile augmente graduellement depuis la zone d'ancrage pour atteindre un maximum le long de l'aile et décroître ensuite vers l'extrémité de ladite aile. L'angle d'attaque élevé de la partie médiane de l'aile permet d'obtenir une sustentation élevée à de faibles vitesses, ceci sans augmentation sensible de la traînée jusqu'à ce que l'air s'écoule à une vitesse de plus de 180 noeuds. Ce système permet d'obtenir une conception à l'épreuve de toute défaillance étant donné que l'aile ne peut s'arracher à l'effet de sol, et ceci indépendamment de la motorisation. Les dérives de queue divergentes (19, 20) permettent de minimiser l'inclinaison latérale lors de tournants, et de maintenir ainsi le coussin d'air sous l'aile d'extrémité.
PCT/AU1996/000698 1995-11-06 1996-11-05 Vehicule a effet de sol WO1997017241A1 (fr)

Priority Applications (3)

Application Number Priority Date Filing Date Title
NZ320036A NZ320036A (en) 1995-11-06 1996-11-05 Ground effect vehicle capable of operation above the ground or water has downwardly extending wings
AU72697/96A AU716801B2 (en) 1995-11-06 1996-11-05 Ground effect vehicle
EP96934221A EP0859715A4 (fr) 1995-11-06 1996-11-05 Vehicule a effet de sol

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
AUPN6387A AUPN638795A0 (en) 1995-11-06 1995-11-06 Ground effect vehicle
AUPN6387 1995-11-06

Publications (1)

Publication Number Publication Date
WO1997017241A1 true WO1997017241A1 (fr) 1997-05-15

Family

ID=3790712

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/AU1996/000698 WO1997017241A1 (fr) 1995-11-06 1996-11-05 Vehicule a effet de sol

Country Status (4)

Country Link
EP (1) EP0859715A4 (fr)
AU (1) AUPN638795A0 (fr)
NZ (1) NZ320036A (fr)
WO (1) WO1997017241A1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1999033690A1 (fr) 1997-12-24 1999-07-08 Otarid Consult Limited Vehicule a effet de sol et a coussins d'air statiques permettant des vitesses reduites et de faire du sur place
JP2007190954A (ja) * 2006-01-17 2007-08-02 Fjc:Kk 飛翔舟船並びに翼
RU2729114C1 (ru) * 2019-11-14 2020-08-04 Федеральное государственное унитарное предприятие "Центральный аэрогидродинамический институт имени профессора Н.Е. Жуковского" (ФГУП "ЦАГИ") Экранолёт

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3190582A (en) 1964-01-02 1965-06-22 Collins Radio Co Ground effects utilizing and transition aircraft
FR2049012A1 (fr) * 1969-03-28 1971-03-26 Harley Rene
US3611111A (en) 1970-11-09 1971-10-05 Gen Motors Corp Inverter commutation voltage limiter
US3627235A (en) 1968-12-07 1971-12-14 Alexander M Lippisch Wing arrangement
US3830179A (en) 1972-06-20 1974-08-20 A Lippisch Ground effect flying surface
DE2547945A1 (de) * 1975-10-27 1977-04-28 Rhein Flugzeugbau Gmbh Tragfluegelausbildung fuer staufluegelfahrzeuge
US4159086A (en) * 1974-08-09 1979-06-26 Rhein-Flugzeugbau Gmbh Wing construction for surface effect vehicle
DE2942882A1 (de) * 1979-10-24 1981-05-07 Vereinigte Flugtechnische Werke Gmbh, 2800 Bremen Staufluegelfahrzeug
US4705234A (en) * 1985-04-10 1987-11-10 Bourn Ronald L Ram wing surface effect vehicle
US5314035A (en) * 1992-08-10 1994-05-24 Schoell Harry L Surface effect vehicle

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3190582A (en) 1964-01-02 1965-06-22 Collins Radio Co Ground effects utilizing and transition aircraft
US3627235A (en) 1968-12-07 1971-12-14 Alexander M Lippisch Wing arrangement
FR2049012A1 (fr) * 1969-03-28 1971-03-26 Harley Rene
US3611111A (en) 1970-11-09 1971-10-05 Gen Motors Corp Inverter commutation voltage limiter
US3830179A (en) 1972-06-20 1974-08-20 A Lippisch Ground effect flying surface
US4159086A (en) * 1974-08-09 1979-06-26 Rhein-Flugzeugbau Gmbh Wing construction for surface effect vehicle
DE2547945A1 (de) * 1975-10-27 1977-04-28 Rhein Flugzeugbau Gmbh Tragfluegelausbildung fuer staufluegelfahrzeuge
DE2942882A1 (de) * 1979-10-24 1981-05-07 Vereinigte Flugtechnische Werke Gmbh, 2800 Bremen Staufluegelfahrzeug
US4705234A (en) * 1985-04-10 1987-11-10 Bourn Ronald L Ram wing surface effect vehicle
US5314035A (en) * 1992-08-10 1994-05-24 Schoell Harry L Surface effect vehicle

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
"janes high-speed marine craft, twenty-sixth edition 1993-94"
"janes surface simmers", 1991, pages: 368
See also references of EP0859715A4

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1999033690A1 (fr) 1997-12-24 1999-07-08 Otarid Consult Limited Vehicule a effet de sol et a coussins d'air statiques permettant des vitesses reduites et de faire du sur place
JP2007190954A (ja) * 2006-01-17 2007-08-02 Fjc:Kk 飛翔舟船並びに翼
RU2729114C1 (ru) * 2019-11-14 2020-08-04 Федеральное государственное унитарное предприятие "Центральный аэрогидродинамический институт имени профессора Н.Е. Жуковского" (ФГУП "ЦАГИ") Экранолёт

Also Published As

Publication number Publication date
NZ320036A (en) 1998-09-24
AUPN638795A0 (en) 1995-11-30
EP0859715A1 (fr) 1998-08-26
EP0859715A4 (fr) 2000-06-28

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