US3830448A

US3830448A - Aero skimmer

Info

Publication number: US3830448A
Application number: US00263769A
Authority: US
Inventors: A Lippisch
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-06-19
Filing date: 1972-06-19
Publication date: 1974-08-20
Anticipated expiration: 1991-08-20
Also published as: CA987376A

Abstract

A combination air and water vehicle capable of operation as a boat at low speeds, as a ''''Ram Wing'''' ground effect operational craft at higher speeds, and as an aeroplane above the ground effect zone. The craft has two opposite truncated triangle wings with a dihedral angle and reverse taper having short cord ends attached to the fuselage and largest cord ends attached to wing end floats. These two opposite side wings form with the wing end floats two ram air chambers. Dual fins with rudders extend above the rear outer tips of the wings and mount outboard directed stabilizers, with combination elevators and ailerons, extending out well beyond the wing outer ends.

Description

United States Patent 1191 I 1111 3,830,448

Lippisch Aug. 26, 1974 AERO SKIMMER [76] Inventor: Alexander M. Lippisch, 3450 Pmflary Exam" 'er Duane Reger Cottage Grove Ave S- Cedar Assistant ExammerJesus D. Sotelo Rapids, Iowa 22403 Attorney, Agent, or FirmWarren I-l. Kintzinger [22] Filed: June 19, 1972 [21] Appl. No.: 263,769

[57] ABSTRACT U.S. R, A combination air and water vehicle apable of opera- [5 Cl. tion as a boat at low peeds as 3 Ram wing ground Fleld of Search 12 12 12 effect operational craft at higher speeds, and as an 244/23 23 23 35 45, aeroplane above the ground effect zone. The craft has 119; D71/1 two opposite truncated triangle wings with a dihedral angle and reverse taper having short cord ends at- [56] References Cited tached to the fuselage and largest cord ends attached UNITED STATES PATENTS to wing end floats. These two opposite side wings form 1,459,916 11/1946 Zabiak 1371 1 F with the wing end floats two Yam air chambefs- Dual 2,364,676 12/1944 Warn r '244 15 fins with rudders extend above the rear outer tips of 2,364,677 12/1944 Warner 1 244/15 the wings and mount outboard directed stabilizers, ,582 6/1965 Lippisch 2 1 2 R with combination elevators and ailerons, extending 3,627,235 l2/l97l Lipplsch 1 244/12 R ut ll b yond the wing outer ends. 3,661,111 5/1972 Lippisch 1 14/67 A v FOREIGN PATENTS OR APPLICATIONS 15 Claims 3 Drawing Figures 719,428 4/1942 Germany D7l/l D PAIENIEB mszomu sum 1 or .2

PAlENIiumszomu Z 3'.aa0 44e sum 20: 2

W P U ll FlG.3.

AERO SKIMMER This invention relates in general to a vehicle that, particularly in an amphibian or seaplane version, is capable of operation as a boat at low speeds, as a Ram Wing ground effect operational craft at higher speeds, and that is capable of flight as an aerodynamic vehicle above the ground effect zone. While there are some features common to a greater or lesser degree with some of my previously issued patents, U.S. Pat. No. 3,190,582, issued June 22, 1965, U.S. Pat. No. 3,627,235, issued Dec. 14, 1971, and US. Pat. No. 3,661,111, issued May 9, 1972, my present invention features two opposite truncated triangle wings with a dihedral angle and a reversed taper having short cord ends attached to the fuselage and longest cord ends attached to wing end floats. The two opposite side wings are convex on the top and generally concave on the bottom with trailing edges respectively in generally a common plane with the bottoms of the-wing end floats. Further, dual fins with rudders are mounted towardthe rear of the wings extending above the rear of the wing end floats and stabilizers having, in some versions, combination elevators and ailerons mounted to extend in outboard directions from the respective fins and beyond the outer ends of the wings.

With various vehicles of the ram air ground effect type, particularly those propelled by a water propeller or water jet, a horizontal stabilizer surface, located at the center behind the wing, is often affected by the water spray. and foam from the propeller or jet wake. Such horizontal stabilizer surfaces are used to neutralize tendency of a vehicle wing in ground effect becoming unstable with increasing vehicle distance from the ground. This longitudinal instability with increased ground effect spacing under the wing arises since the air pressure cushion beneath the wing is lessened especially toward the rear of the wing thereby causing forward movement of the center of aerodynamic lift pressure. Another consideration is that aerodynamic effectiveness of the stabilizer is decreased by drag due to the friction of water spray droplets on stabilizer surfaces. Further, as a ground effect vehicle moves away from a ground or water surface the lift action of the wings causes an increasing Downwash" behind the wing and an increasing Upwash airflow vector outside the wing span ends in an air flow tip vorticies action extending behind the wing. The upcurrent airflow vector partially impinging on stabilizers from below, that is with stabilizers mounted on fins at the rear of the wing outer ends and extending outboard from wing ends, causes an increase in lift of these surfaces. This, advantageously, not only neutralizes the forward travel of the center of pressure under the wing but also reduces the angle of incidence bringing the craft back toward the ground or water surface in an automatic trimming and A further object is to position stabilizers and elevators and other control surfaces generally away from the region of Rooster Tail generated with vehicles employing water propeller drive and minimize drag generated by friction of water spray droplets on vehicle surfaces.

Other objects are to improve vehicle riding characteristics, make lateral stability better and make the vehicle more responsive to terrain variations or water wave action while operating in ground effects.

Features of the invention useful in accomplishing the above objects include, in a vehicle capable of operation in ground effects over ground or water and as an aerodynamic vehicle above the ground effects zone, and also as a boat, a fuselage with a planing boat type deadrise bottom surface-Two opposite side truncated triangle wings extend from low on opposite sides of the fuselage with a dihedral angle and a reversed taper having short cord ends attached to the fuselage and longest cord ends attached to wing end floats. These opposite side wings are convex on the top and generally concave on the bottom and have trailing edges generally in a common plane with the bottoms of the wing end floats. Much greater lift is provided in ground effects by each side wing out toward the wing end floats than toward the fuselage ends and thereby provide a greatly improved terrain and wave action transverse adjusting characteristics and also an improved ride. Dual fins at the rear outer ends of the wings mount at their tops out-.

board extended stabilizers having combination elevators and ailerons.

Specific embodiments representing what are presently regarded as the best modes of carrying out the invention are illustrated in the accompanying drawings.

In the drawings:

FIG. 1 represents a perspective view of a ground effect vehicle according to the invention;

FIG. 2, a front view of a vehicle quite similar to the embodiment of FIG. 1, equipped, however, with an air driving propeller in addition to a water propeller that may be-retracted, in place of the vehicle propulsion water propeller of FIG. 1; and,

FIG. 3, a top plan view of a vehicle similar to both those of FIGS. 1 and 2, equipped, however, with only an air propeller as the vehicle propulsive means.

Referring to the drawings:

The surface, or ground, effect water and air vehicle 10 of FIG. 1 has a fuselage ll shaped as a floating body with planing boat type deadrise bottom surfaces 12 and includes a passenger cabin 13. Opposite side truncated

triangle wings

14L and 14R with a diehedral angle and reversed taper have short cord ends 15 attached to the fuselage and longest cord ends 16 attached to

wing end floats

17L and 17R. Since the only material differences between the vehicle embodiments of FIGS. 1, 2, and 3 reside in the propulsive means employed descriptive numbers are the same and the different views will be considered, as a matter of convenience, as being of the same vehicle 10. With the ground effects operational vehicle 10 of FIG. 1 propulsion is provided by a water propeller l8 suspended beneath the vehicle at the rear of fuselage 11 with drive through a drive pedestal 19 extended from a motor (not shown) contained within the rear of the fuselage. A water jet propulsion system could be used in place of the water drive propeller system shown. The vehicle 10 of FIG. 2 uses water propeller 18 for water drive propulsion at slower speeds with, in some units, the drive pedestal l9 and propeller l8 retractable to containment within the fuselage 11, and an air propeller 20 driven by a motor within the fuselage for higher speed operation in ground effects and in full flight as an aeroplane. With the version of FIG. 3 the vehicle 10 is driven solely by the air propeller and a drive motor within the fuselage 11.

In any event while the leading edges 21 of the

wings

14L and 14R are shown to be straight as seen in the top plan view of FIG. 3 they may be slightly swept back or forward without any material resulting change in performance. Much more significant, however, is that the trailing edges 22 of the

wings

14L and 14R are swept back approximately 60 and could be anywhere in the swept back range of approximately 45 to 75 with a taper ratio between the inner and outer wing cords being in the range of approximately l:2 to even more. Thus, with the leading edges 21 angled upward from their connection to the fuselage 11 to their connection with flat vertical inner faces 23 of outer

wing tip floats

17L and 17R the ram air receiving volume beneath the

wings

14L and 14R increases considerably from the areas adjacent to the fuselage 11 to the areas adjacent to the

floats

17L and 17R. This coupled with the fact that the trailing edges 22 of the

wings

14L and 14R are substantially in a common plane that is also generally common to the bottom of

floats

17L and 17R throughout the longitudinal length of the outer wing tip cord ends 16 results in effective ground effects lift of the

wings

14L and 14R being greater out toward the wind end floats than in toward the fuselage 11. Thus, the vehicle is advantageously much more responsive laterally to terrain variations or water wave action while operating in ground effects. It should be noted that while the surfaces of

wings

14L and 14R are convex on top that they may not be concave on the bottom although the ram air chamber under each defined with the wing end floats may be considered generally as a concavity..

Wing end floats 17L and 17R project forwardly from their connection with outer wing ends with the flat ver-. tical inner faces 23 extended to the forward ends of the floats. The

floats

17L and 17R are also equipped-with outboard facing

deadrise bottom surfaces

24L and 24R extending from the forward ends of the floats outward and downward to divert spray outward away from the wings when the floats are in the water planing state. At the rear end of

floats

17L and 17R and at the rear outer wing tips

vertical fins

25L and 25R are mounted and carry

rudder control surfaces

26L and 26R. Further, the

fins

25L and 25R are asymmetrically shaped as a useful arrangement in a avoiding dead spots in aerodynamic reaction forces.

Stabilizers

27L and 27R are mounted to extend in an outboard direction from the tops of the

respective fins

25L and 25R. This enables the

stabilizer

27L and 27R and the combination elevators and

ailerons

28L and 28R they carry to extend outwardly outside the outer tips of the

wings

17L and 17R. When the vehicle 10 moves higher away from the ground or water surface higher in ground effects and in full flight out of ground effects the lift of the wings causes a Downwash behind the wing surfaces and an Upwash outside the wing outer ends forming wing tip vortices behind the wing. With the outward extended position of the

stabilizers

27L and 27R beyond the outer ends of the wings and higher than the wings the upcurrent air flow of Upwash hits the stabilizers from below thereby increasing lift of these surfaces. This action not only neutralizes the forward travel of the center of pressure of the wing but also acts to reduce the vehicle 10 angle of incidence to automatically bring the craft back down toward the ground or water surface well down in ground effects. Thus, the positioning of the stabilizers outside and well behind the center span of the wing is significant in the attainment of automatic trim stability of the craft in ground effect. The vehicle is fullycapable of transition to full flight outside of ground effects however, by controlling the combination elevators and ailerons to bring the craft out of ground effects in spite of the Upwash automatic trimming force exerted on the stabilizers. This can be accomplished even with vehicle 10 of FIG. 1 by attaining sufficient speed with water propeller l8 drive and then gliding back down into ground effects and propeller 18 in driving reimmersion in water.

With this vehicle arrangement the horizontal stabilizer surfaces are located where they are least likely to be affected by water spray from a propeller wake such as a Rooster Tail or from a propelling water jet. Further, undesired friction by water spray droplets on stabilizer, rudder and control surfaces is greatly lessened. In the vehicles 10 employing water propulsion the drive system is located near the vehicle center of gravity with minimum change in position to the water with change in the angle of incidence of the vehicle and its wings. This is accomplished readily with the center cut-out effect of the wing rear toward the fuselage.

Whereas this invention is illustrated and described with respect to a plurality of embodiments thereof, it should be realized that various changes may be made without departing from the essential contributions to the art made by the teachings hereof.

I claim:

1. A vehicle capable of being supported above water by utilizing an air cushion forming due to the ground effect phenomenon, and as an aerodynamic vehicle in flight above the ground effect area of operation, including a fuselage, opposite side wings extended from the fuselage, fin means, stabilizer means, and vehicle propulsion means; each of the opposite side wings with a dihedral angle having a ram air chamber beneath the wing open toward the front; wing tip ram air chamber enclosure means for each opposite side wing extending downward from connection with the outer wing tip end to a lower edge generally co-planer with the trailing edge of the wing and longitudinally coextensive through the longitudinal extent of the cord of the outer wing tip end; and with said stabilizer means including two opposite side sections mounted higher than the wings projecting transversly outward beyond the outer wing tip ends at a longitudinal location generally well to the rear of the longitudinal center of lift of the wing structure.

2. The vehicle of claim 1 wherein the trailing edges of the opposite side wings each have a sweep back falling in the range of approximately 45 to 3. The vehicle of claim 2 wherein the opposite side wings are truncated triangle wings in plan view with short cord ends at the fuselage having a taper ratio to long cord outer ends falling in the range of from approximately l:2 to more.

4. The vehicle of claim 3, wherein said vehicle propulsion means includes a water propeller suspended from the rear of the fuselage.

5. The vehicle of claim 4, wherein said vehicle propulsion means also includes an air propeller.

6. The vehicle of claim 3, wherein said vehicle propulsion means includes an air propeller.

7. The vehicle of claim 3, wherein said wing tip ram air chamber enclosure means for each opposite side wing is a wing tip float.

8. The vehicle of claim 7, wherein said wing tip floats are extended forward from the leading edge of the wing.

9. The vehicle of claim 8, wherein said wing tip floats have flat inboard surfaces next to the wing outer cord ends; and outboard facing deadrise bottom surfaces.

10. The vehicle of claim 3, wherein said fin means are dual fins mounted to extend vertically from the top rear outer corners of the vehicle opposite side wings.

11. The vehicle of claim 10, wherein said fin means mount the two opposite side sections of the stabilizer means at the top of the fins to extend, respectively, in the outboard direction therefrom.

12. The vehicle of claim 10, wherein said fin means includes rudder means; and said stabilizer means mounts moveable control surface means.

13. The vehicle of claim 12, wherein said moveable control surface means mounted on said stabilizer means include combination elevator and aileron means.

14. ln a combination air and water vehicle capable of operation as a boat at low speeds, as a Ram Wing" ground effect operational craft at higher speeds, and as an aerodynamic vehicle above the ground effect zone: a fuselage; propulsive means; two opposite truncated triangle wings with a dihedral angle and reverse taper having short cord ends attached to the fuselage and long cord ends; wing end floats attached to said wing long cord ends; dual fins extended from the rear outer tips of the wings; and outboard directed stabilizers mounted to extend outward from said dual fins beyond the wing outer ends.

15. The combination air and water vehicle of claim 14, wherein said fuselage has a boat like bottom with opposite side directed dead-rise bottom surfaces; and with said propulsion means including propeller means mounted at the rear of the fuselage.

Claims

2. The vehicle of claim 1 wherein the trailing edges of the opposite side wings each have a sweep back falling in the range of approximately 45* to 75* .

3. The vehicle of claim 2 wherein the opposite side wings are truncated triangle wings in plan view with short cord ends at the fuselage having a taper ratio to long cord outer ends falling in the range of from approximately 1:2 to more.

14. In a combination air and water vehicle capable of operation as a boat at low speeds, as a ''''Ram Wing'''' ground effect operational craft at higher speeds, and as an aerodynamic vehicle above the ground effect zone: a fuselage; propulsive means; two opposite truncated triangle wings with a dihedral angle and reverse taper having short cord ends attached to the fuselage and long cord ends; wing end floats attached to said wing long cord ends; dual fins extended from the rear outer tips of the wings; and outboard directed stabilizers mounted to extend outward from said dual fins beyond the wing outer ends.