RU2406626C2 - Air-cushion amphibian - Google Patents

Abstract

FIELD: transport.

SUBSTANCE: invention relates to aircraft engineering, namely, to amphibian with air-cushion landing gear. Amphibian comprises fuselage, engines with propellers, wing consisting of wing center section and outer wing, tail unit with aerodynamic control surfaces of inversed V-shaped and located to be blown by propellers airflows. Air-cushion landing gear with balloon skirt made up of flexible perforated envelopment which, when inflated, features toroidal shape, wheel landing gear and sliding support arranged inside said envelopment. Said sliding support represents trapezoidal plate made from flexible material. Plate larger side has shoe, while smaller side is hinged to fuselage bottom flat surface to be connected to toroidal surface of envelopment. Outer wings can have spars, the space between said spars being tightly communicated with wing center section inner space. Walls of outer wing rear spars can be furnished with perforations arranged over wing span separated from hinged rear flaperons by flexible curved walls. Lower sides of the latter can be attached to spar walls, under the perforated holes, while to upper sides jointed are boards pressed against flaperon upper surfaces and rear spar top flanges. Air-cushion landing gear can comprises radial-flow blowers to be mounted in wing center section. Said blowers can be could, via appropriate transmissions, with aforesaid engines.

EFFECT: higher safety due to improved aerodynamic and hydrodynamic characteristics.

10 cl, 6 dwg

Description

Description

The invention relates to the field of aviation, in particular to amphibious aircraft, and can be used in various industries producing and operating aircraft and other vehicles that can move along unprepared areas of the earth and water surface.

Airplane with hovercraft chassis.

A well-known LMA amphibious aircraft with an air-cushion landing gear containing the fuselage, engines, a wing consisting of a center wing and consoles, tail unit, an air-cushion landing gear with a balloon guard in the form of an elastic shell, which has a toroidal shape when supercharged by air (see AIAA Paper No. 79-0849, p. 53-61).

In the inflated state, such a membrane forms a toroidal shell fixed on the lower surface of the fuselage, the inner surface of which is perforated with many holes. The air flowing out of the openings creates in the cavity formed between the fuselage, the membrane and the abutment surface an area of increased pressure that balances the weight of the aircraft, providing it with non-contact movement when taking off on an air cushion over a surface of any hardness.

However, the LMA amphibious aircraft is not safe enough when operated from unprepared sites of different hardness, due to the lack of auxiliary takeoff and landing devices.

The objective of the invention is to increase the safety of operation of the aircraft by improving its aerodynamic and hydrodynamic characteristics.

This problem is solved by the fact that an amphibious aircraft with an air-cushion landing gear is proposed, comprising a fuselage, propeller engines, a wing consisting of a center section and consoles, a tail unit with air rudders having an inverted V cross-section and arranged to blow air flows from propellers of engines, an air cushion chassis with a balloon guard in the form of an elastic shell with holes, which, when supercharged with air, has a toroidal shape, a wheeled chassis and a sliding support, cat rye are located within the contour of said resilient shell.

The sliding support is made in the form of a trapezoidal plate made of elastic material, provided with a shoe on the side of the larger base, and mounted on the flat surface of the fuselage bottom with a hinge from the side of the smaller base so that it can be mated to the toroidal surface of the shell.

The wing consoles are made with spars, the cavities between which are hermetically connected to the center section cavity.

The walls of the rear side members of the wing consoles are provided with a profiled hole throughout the span, fenced off from the flanges of the rear side members pivotally mounted on the lower shelves by elastic curved walls, the lower sides of which are fixed to the side members walls below the holes, and the upper sides of the flaps are elastically connected pressed to the upper surfaces of the flaps rear side members shields.

The air-cushioned chassis includes centrifugal fans mounted in the center section of the wing center section.

Centrifugal fans are connected by respective transmissions having couplings to the mentioned motors.

The number of holes in said elastic shell is greater on the side of the bow than on the tail.

The wheeled chassis is located on the front of the fuselage in front of the plate.

The bearing surfaces of the tail unit are interconnected by a cylindrical surface.

The air rudders are equipped with horn compensators located below the tail beams on which the plumage is installed.

The slide support plate is made of greater rigidity from the side of the smaller base than from the side of the larger base.

The slide support plate has a detachable connection with the shoe.

Amphibious aircraft is represented by drawings, where

figure 1 - frontal projection of the aircraft (side view);

figure 2 is a view of the aircraft from above (half view) and bottom (half view);

figure 3 is a front view of the aircraft;

figure 4 is a cross section of the fuselage in the center section;

5 is a sectional view of a wing console in a cruise flight configuration and in a take-off and landing configuration;

figure 6 is a cross section of the bow of the fuselage in the cockpit area;

In the drawings, the positions indicated:

1. fuselage

2. crew cabin and passengers

3. nose

4. side edges

5. board

6. propeller propulsion engine

7. wing console

8. tail boom

9. tail with inclined stabilizers

10. transition with a cylindrical surface between inclined stabilizers

11. steering wheel

12. horn aerodynamic compensator

13. membrane

14. the nozzle on the membrane 13 from the rear of the fuselage 1

15. nozzle on the membrane 13 from the side of the nose 3 of the fuselage 1

16. wheel chassis wheel

17. slide support plate

18. brake shoe

19. high pressure centrifugal fan

20. transmission

21. clutch

22. engine nacelle 6

23. engine pylon 6

24. hole in the wall of the rear side member of the wing console 7

25. curved wall

26. visor

27. flaperon

28. rear spar

29. gap

An airplane with an air-cushioned landing gear contains (Fig. 1) a fuselage 1, a smoothly varying lenticular section, integrally mated to the cockpit and passengers, having a convex surface 3 with rounded side edges 4 in the bow.

The fuselage 1 is equipped, starting from the interface with the wing consoles 7 to the end, bent upward upward at an angle of about 45 ° 5. At the installation site of the consoles 7, the wing 5 wings provide cylindrical cavities for installing engines 6 with propellers, and, bending in the opposite direction , - the integral pairing of the fuselage 1 with the consoles 7 of the wing.

The tail of the fuselage 1 near the plane of symmetry is shorter than the sides 5. At the same time, its bent upwards, slightly converging along the length of the side 5 form short tail beams 8, on which the tail unit 9 is installed in the form of an inverted V. The bearing surfaces of the tail unit are interconnected by a transition 10 with a cylindrical surface and located in the nuclei of the satellite jets of propellers of engines 6.

The rudders 11 of the tail are equipped with horn aerodynamic compensators 12, which are located below the beams 8.

On the convex part of the lower surface of the fuselage 1 is installed with pre-tensioning elastic, made of two-dimensionally stretchable material, the membrane 13 in the form of an elongated ring, hermetically fixed along the outer and inner perimeters of the ring. The membrane 13 is made with several concentric rows of profiled holes forming a system of air nozzles 14, 15. The number of rows of nozzle holes 15 in the nose is substantially larger than in the tail of the membrane 13. The ratio of the number of holes in the nose and tail of the membrane 13 is selected in such a way so that the pressure in the nose 3 of the air cushion (before the septum) is greater than the pressure in the tail of the cushion (after the septum) so that the resulting pressure force of the air cushion is located near the center of gravity of the aircraft.

In the nose part 3 of the fuselage 1, on its lower surface, which is flat in its middle part, a retractable brake wheel 16 of the wheel chassis is installed as a front support, and a flexible plate 17 of the sliding support with replaceable brake shoes 18 is articulated with its short base back support.

The brake wheel 16 and the plate 17 of the slide support form an auxiliary wheel-ski chassis.

The inter-spar volumes of the wing consoles 7, hermetically connected to the inter-spherical volume of the center section, form a single volume, inside of which two high-pressure centrifugal fans 19 are installed, which are connected to main engines 6 installed in the nacelles 22 above the upper surface of the fuselage 1 through transmissions 20 with clutch 21 on short inclined pylons 23.

The walls of the rear side members of the wing consoles 7 are provided with profiled openings 24 across the entire span. On these walls below the holes 24, elastic curved walls 25 are fixed with their lower sides, the upper sides of which are resiliently connected to the shields 26 on the upper surfaces of the consoles 7.

Shields 26 are constantly pressed to the upper surfaces of the flaperons 27, pivotally mounted on the lower shelves of the rear side members of the wing consoles 7.

When the flaperons 27 are set in a cruising flight position, the front edges of the flaps 26 are firmly pressed against the rounded upper shelves of the rear side members 28. When the flaperons 27 are set in the take-off or landing position, the curved walls 25 are deflected and the flaps 26 are moved back so that between the curved walls 25 and the upper shelves of the rear side members 28 formed by profiled slots 29.

Before takeoff or landing, the pilot deflects the flaperons 27 to the appropriate position and engages the clutches 21 of the transmissions 20. The impellers of the fans 19 are rotated. In this case, a rarefaction is created in the inter-spar volume of the center wing and wing consoles 7, and the boundary layer of air flowing around the upper surface of the wing consoles 7 is sucked through the profiled slots 29 open on the upper surface of the consoles and guided by curved walls 25 to the holes 24 in the walls of the rear side members 27 of the consoles 7 , enters the inter-spar wing volume and falls on the blades of the impellers of the fans 19, where it is compressed, accelerated and thrown into the cavity between the bottom of the fuselage 1 and its tight-fitting membrane 13.

Under the influence of air pressure, the membrane stretches, becoming a torus, and air constantly entering the inflated membrane shell 13 escapes through a system of profiled nozzle openings 14.15 into the space between the bottom of the fuselage 1, the elastic inflated membrane shell 13 of a toroidal shape and the supporting surface, creating the area of high pressure (air cushion), which raises and holds the plane at a certain height from the supporting surface.

Suction by the fans 19 of the boundary layer of air in front of the deflected flaperons, providing continuous flow around them, allows the flaperons 27 to be installed at a larger angle than without suction.

At the same time, the increase in the lift coefficient of the wing consoles 7 increases, which leads to a decrease in the stall speed and takeoff and landing speeds, as well as to a reduction in takeoff and landing distances. All of these factors contribute to increased safety on takeoff and landing.

In flight, the fully convex, with rounded sides 4 geometry of the nose 3 of the fuselage 1 of the aircraft prevents the formation of powerful vortices on it when it is surrounded by an incoming air stream.

At the same time, the margin of longitudinal stability increases and the linear nature of its change in the angle of attack to supercritical values of this angle is maintained. This increases the safety of operation of the aircraft in all flight modes.

The shortened tail part of the fuselage 1 of the aircraft with elongated tail beams 8, on which the tail unit 9 is mounted, ensures its flow around with an incoming air stream at speeds close to the speeds of the undisturbed stream. At the same time, the controllability of the aircraft improves and remains high to supercritical angles of attack. This also contributes to the horn aerodynamic compensation of the rudders 11, which allows to expand the range of their deviation. The horn compensators 12 of the rudders 11 located at the bottom of the tail beams 8 together with their lower parts increase the stability and controllability of the aircraft, especially at positive angles of attack.

The pair of bearing surfaces of the plumage with a cylindrical surface 10 reduces the harmful interaction of the two halves of the tail unit 9 and increases its efficiency. All this helps to improve flight safety in all its modes.

The placement of the axes of the engines 6 near the planes of the chords of the tail stabilizers 9 contributes to a more intensive blowing of the tail 9 and thereby increases the control efficiency when accurately maneuvering the aircraft on an air cushion before takeoff and after landing. These measures increase the safety of operation of the aircraft both in cruising flight and in taxiing.

Before boarding the water on the auxiliary landing gear, the pilot deflects the flexible plate 17 of the sliding support pivotally mounted on the bottom of the fuselage so that at the moment of contact the shock loads that occur when the aircraft comes into contact with water are repaired and glide on the trailing edge of the plate 17, which performs thereby redan functions.

When moving on an air cushion, the sliding support plate 17 is deflected to the maximum angle, and its trailing edge is at the level of the lower surface of the membrane shell 13 of the air cushion guard, and the flexible sides are in close contact with the inflated guard so as to divide the volume of the air cushion in the longitudinal direction by two parts and increase the longitudinal stability of the aircraft when moving on an air cushion.

For mechanical braking of the aircraft, it is sufficient to reduce the air supply to the cushion by reducing the speed of the engines 6 in the nacelles 22 and the associated fans 19. Moreover, the brake shoes 18 on the trailing edge of the plate of the sliding support contact with the supporting surface the stronger, the lower the pressure in the air cushion.

Claims (11)

1. An amphibious aircraft with an air-cushion landing gear, comprising a fuselage, propeller engines, a wing consisting of a center wing and consoles, a tail unit with air rudders having an inverted V cross-section in shape and capable of being blown by air flows from propellers engines, an air cushion chassis with a balloon guard in the form of an elastic shell with holes, which, when supercharged with air, has a toroidal shape, a wheeled chassis and a sliding support, which are located inside the contour of mentioned elastic membrane, characterized in that the plain bearing is formed as a trapezoidal plate of resilient material provided by the greater base of the shoe from the weaker base by a hinge fixed to the flat bottom surface of the fuselage to mate with the toroidal surface of the shell. 2. The aircraft according to claim 1, characterized in that the wing consoles are made with spars, the cavities between which are hermetically connected to the center section cavity. 3. The aircraft according to claim 1, characterized in that the walls of the rear side members of the wing consoles are provided with a wide range of profiled openings, fenced off from the rear flanges of the flappers pivotally mounted on the lower shelves by elastic curved walls, the lower sides of which are fixed to the side members walls below the holes, and with the upper sides are elastically connected pressed against the upper surfaces of the flaperons and the upper shelves of the rear side members of the flaps. 4. The aircraft according to claim 1, characterized in that the hovercraft includes centrifugal fans installed in the wing center section. 5. The aircraft according to claim 4, characterized in that the centrifugal fans are connected by respective transmissions having couplings with the said engines. 6. The aircraft according to claim 1, characterized in that the number of holes in said elastic shell is greater from the side of the bow than from the tail. 7. The aircraft according to claim 1, characterized in that the wheeled landing gear is located on the side of the nose of the fuselage in front of the plate. 8. The aircraft according to claim 1, characterized in that the bearing surfaces of the tail unit are interconnected by a cylindrical surface. 9. The aircraft according to claim 1, characterized in that the air rudders are equipped with horn compensators located below the tail beams on which the plumage is installed. 10. The aircraft according to claim 1, characterized in that the sliding support plate is made of greater rigidity from the side of the smaller base than from the side of the larger base. 11. The aircraft of claim 10, characterized in that the said plate of the sliding support has a detachable connection with the shoe.

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