GB2531468A

GB2531468A - A wing-in-ground effect vehicle having a lift system

Info

Publication number: GB2531468A
Application number: GB1601534.9A
Authority: GB
Inventors: Gonzague Leruth
Original assignee: Exclin Ltd
Current assignee: Exclin Ltd
Priority date: 2016-01-27
Filing date: 2016-01-27
Publication date: 2016-04-20
Anticipated expiration: 2036-01-27
Also published as: GB2531468B; GB201601534D0; WO2017129953A1

Abstract

A wing-in-ground-effect vehicle 1 comprises a lift system with a pressure vessel or tank 2 and a set of nozzles 3-8. The lift system allows the wing-in-ground effect vehicle to take off. The pressure vessel holds a fluid, such as air, under pressure. The fluid is delivered from the pressure vessel to the nozzles via a conduit 17 and may be regulated by a valve which is controlled by a vehicle control system. Compressed fluid from the pressure vessel is expelled through the nozzles on operation of a valve by the vehicle control system to levitate the vehicle and allow the main propulsion system 33a to accelerate the vehicle in horizontal flight until sufficient lift is generated by the ground effect wings. The lift system may also discharge the nozzles to reduce the risk of collision with the ground or water through the delivery of a lift that increases the vehicle clearance from the ground or water, or stabilizes the vehicle roll and pitch angles.

Description

A Wing-In-Ground Effect Vehicle Having A Lift System.

Technical Field

roou This invention relates to a wing-in-ground effect vehicle especially means to facilitate takeoff.

[002] A wing-in-ground effect vehicle is a vehicle that attains level flight near the ground or water by making use of the aerodynamic interaction between the wings and the surface known as ground effect. A wing-in-ground effect vehicle requires some forward velocity to generate a ground effect cushion and benefit from the dynamic lift that supports its level flight.

[003; A wing-in-ground effect vehicle typically follows an initial takeoff phase to attain the required forward velocity. Therefore, the design of a wing-in-ground effect vehicle generally has to provide a mean to allow takeoff.

Prior Art

[004] Conventional wing-in-ground effect designs include an undercarriage which provides; wheels, a marine hull, skis, floats or a means to produce a static cushion of air (for example a hovercraft) under the vehicle which are combined with the main propulsion system to allow takeoff. However, these conventional designs may exclude takeoff from some surfaces, such as an uneven ground surface or rough water. These conventional undercarriage designs may also add a significant weight for the purpose of the takeoff capability, which translates into additional energy and cost required to operate the wing-in-ground effect vehicle. These conventional designs may also increase the vehicle drag coefficient for the purpose of the takeoff capability, which translates into additional energy and cost required to operate the wing-in-ground effect vehicle.

[005; The constraint of maintaining the forward velocity to benefit from the dynamic lift generally limits the possible trajectories a wing-in-ground effect vehicle can follow during a level flight near the ground or water.

[006] A wing-in-ground effect vehicle generally has also to avoid, or at least reduce or minimize, collision with the ground or water to preserve its level flight velocity and avoid damage, typically during turns or with obstacles such as high waves lying in the path of the wing-in-ground effect vehicle.

[007] A wing-in-ground effect vehicle may also encounter vibration during flight over an uneven surface due to the partial or total loss of the ground effect cushion and thus, of the corresponding dynamic lift.

[008] The present invention provides a lift system to alleviate at least one of these problems.

Statement of Invention

[009; Accordingly the present invention provides a wing in ground effect vehicle having a lift system with a pressure vessel to deliver compressed fluid to a lift nozzle arranged to provide a lift thrust.

[010] The lift system allows the wing-in-ground effect vehicle to take off (levitate). The lift system may also allow the wing-in-ground effect vehicle to effect movements for which the dynamic lift is either low or not available, such as hovering, or for landing, particularly vertical landing. The lift system may also reduce the risk of damage or instability due to collision with the ground or water surface by increasing the wing-in-ground effect vehicle clearance from the ground or water. Damage or instability risk may be reduced by the modification of the wing-in-ground effect vehicle pitch and roll angles induced by the lift system. Lift caused by the ground effect is dependent on the height of the vehicle above the underlying surface. Where the surface is uneven this can cause the vehicle to vibrate or bounce. The lift system may be operated to attenuate the vibrations encountered during flight over an uneven surface by delivering a lift thrust that compensates a transient reduction of the dynamic lift provided by the ground effect.

ioiu The lift system includes at least one pressure vessel and one, or preferably a set of lift nozzles. The one or more pressure vessel holds a fluid under pressure.

Preferably the fluid is a gas, such as air, however a liquid or vapor may be used.

The fluid is delivered from the or each pressure vessel to the or each lift nozzle through one or more pipes or through other means. Each or any lift nozzle may also be attached and connected to the pressure vessel. The fluid may be regulated by one or more valves which is typically controlled by a vehicle control system, or by other manual or automatic systems. Each or any lift nozzle may deliver a thrust produced by the jet of the gas flowing out of the lift nozzle. The lift system thrust is the force resulting from the thrust delivered by the lift nozzle.

[012] To allow the wing-in-ground-effect vehicle to takeoff, the force resulting from the lift system thrust and the forces provided by the other propulsion devices must overcome the weight of the wing-in-ground effect vehicle. The lift system thrust therefore requires a force component opposed to the weight of the wing-in-ground effect vehicle. This can be achieved by design of the lift nozzle exit direction, for example the nozzle is directed down. Alternatively the jet expelled from the nozzle may be deflected with some mechanical means, for example a vane. The vane may be fixed or may be steerable to alter the direction of thrust. Alternatively the nozzle may be steered by providing a mean to rotate the lift nozzle, for example the nozzle may be mounted on a gimbal.

[013] The lift system is operated during the takeoff phase by delivering a lift system thrust which is sufficient to provide an initial vertical acceleration to the wing-in-ground effect vehicle. The lift system and the main propulsion device of the wing-in-ground effect vehicle are typically jointly operated during the takeoff phase during which the wing-in-ground effect vehicle is above the ground. The lift system typically no longer needs to be operated for the purpose of takeoff when the wing-in-ground effect vehicle reaches a forward velocity which is sufficient to fly from the wing-in-ground effect. Accordingly the control system may respond to sensed inputs such as air speed indicative of lift to attenuate or amplify the down thrust applied through the nozzle in order to maintain the vehicle altitude.

[014] The lift system may be operated during flight to maintain a ground clearance, or to maintain a vertical speed, or to maintain a vertical acceleration, or to avoid, reduce or minimize a collision with an obstacle lying in the path of the wing-in-ground effect vehicle.

[015] The lift system may be operated during movements of the wing-in-ground effect vehicle for which the dynamic lift required to maintain the wing-in-ground effect vehicle in flight is either low or not available, such as during flight at low speed, during the landing phase or for moving the wing-in-ground effect vehicle in and out a hangar.

[018; The lift system may be operated to maintain the wing-in-ground effect vehicle in a static flight position above the ground.

[017; The lift system may be operated to attenuate the vibrations of the wing-in-ground effect vehicle encountered during a flight, such as the vibrations resulting from a flight over an uneven surface. In this case the control system will respond to perception of an approaching sudden change in the elevation of the approaching ground or sea level to maintain a relatively constant altitude of flight above the nominal or average ground or sea level. Thus in the case of a sudden depression down-thrust may be briefly increased to maintain level flight. In the case of a sudden elevation the nozzles may apply an up-thrust so long as this does not result in collision with the sudden elevation.

[018] The lift system may be operated to stabilize the pitch and roll angles of the wing-in-ground effect vehicle during flight. For example the down-thrust or up-thrust applied on approach to a depression or elevation may be directed through dirigible nozzles or distributed to fore and aft or port and starboard nozzles to minimize unwanted pitch and roll. The control system may control the direction or distribution of thrust in response to input values sensed from trim sensors such as pitch, roll and yaw sensors.

[019; A vehicle control system is typically used to regulate one or more valves located between each pressure vessel and each nozzle to adjust the vertical acceleration and the pitch and roll angles of the wing-in-ground effect vehicle during the operation of the lift system. The vehicle control system typically receives input information from a manual command and from sensors such as accelerometers. The vehicle control system may be linked to one or more position sensor such as a distance-to-ground sensor in order to operate the lift system to maintain a ground clearance during the flight of the wing-in-ground effect vehicle. The vehicle control system may be linked to a fore-looking sensor which provides input information on the ground or water surface contours and obstacles, such as a radar, laser, infrared, acoustic or imaging sensor, in order to operate the lift system to avoid, or at least reduce or minimize, a collision with the ground surface or with an obstacle, such as a high wave, lying in the path of the wing-in-ground effect vehicle.

[020] Each pressure vessel is filled with a fluid, such as air. Each pressure vessel is pressurized before or during flight. Each pressure vessel may be filled and pressurized during flight, typically with at least one air compressor located in the wing-in-ground effect vehicle.

[021; The air compressor may be an electric air compressor powered by an electric battery or a mechanical air compressor typically powered by an engine or turbocharger of the wing-in-ground effect vehicle. The air compressor may be regulated by a pressure control system. The pressure control system typically receives input information from a sensor such as a vessel pressure sensor or from a manual command. The compressed air generated by the air compressor may typically go through an air dryer to remove the water vapor from the compressed air before the compressed air enters the pressure vessel. The pressure vessel may be equipped with a pressure relief valve.

[022] Any pressure vessel holding a high pressure fluid may deliver pressurized fluid to one or more other pressure vessel of the lift system having a lower or equal pressure, typically through a regulation system connecting the pressure vessels through one or more pipes, one or more valves and a pressure control system.

[023] The compressed fluid for any pressure vessel of the lift system may be generated through a chemical reaction. The reaction may be regulated through a regulation system connecting any vessel containing reactant to the pressure vessel through one or more pipes and/or one or more valves. The reaction regulation system may include a catalyst material mesh to catalyze the reaction. The regulation system may also include a pressure control system.

[024] The one or more pressure vessels may be located inside the wings of the wing-in-ground effect vehicle.

[025; The one or more pressure vessel may be inflatable, ie of variable volume to expand or contract as it is inflated or deflated.

[028; The lift nozzles may be convergent-divergent nozzles.

[027] Extra maneuvering nozzles may be provided to the wing-in-ground-effect vehicle in addition to the lift nozzles of the lift system in order to expand the movement capabilities of the wing-in-ground effect vehicle during flight. For example, maneuvering nozzles can provide facility to brake (reverse thrust) and/or lateral movement or a control over the yaw angle of the wing-in-ground effect vehicle. The extra maneuvering nozzles may typically be supplied with compressed fluid from the lift system pressure vessel. The fluid supply may be regulated by valves which are controlled by the vehicle control system.

[02Sf The pressure vessel, nozzle, pipes and valves of the lift system may be wholly or partially duplicated and configured to provide partial or full redundancy, in order to reduce the impact of a failure.

Brief Description of the Drawings

[029] An embodiment of a wing-in-ground effect vehicle with a lift system based on a pressure vessel and a set of nozzles constructed in accordance with the present invention will now be described, by way of example and with reference to the accompanying drawings, which are not necessarily represented to scale, and in which: Figure 1 shows a perspective view; Figure 2 shows a side view with hidden detail; Figure 3 shows a front view; Figure 4 shows a perspective SE view of the lift system Figure 5 is an isometric SW view of the lift system.

Detailed Description of the Drawings

[030] The invention will now be described more fully with references to the drawings, in which preferred embodiments of the invention are presented. The invention may, however, be embodied in many different forms. Like numbers refer to like elements.

[031] The figures illustrate one embodiment of a wing-in-ground effect vehicle 1, having a lift system based on a pressure vessel 2 and a set of nozzles 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14. Afixed ground effect wing iSis attached to a fuselage 16, as conventionally found on wing-in-ground effect vehicles. The pressure vessel 2 is attached inside the fuselage 16. In general, pressure vessels are designed to achieve certain properties according to design parameters, such as volume, maximum storage pressure and dimensions. The set of twelve convergent-divergent nozzles 3-14 is attached to the fuselage 16 and connected through a conduit provided by a set of pipes 17, 18 and valves 19, 20, 21, 22, 23, 24. 25, 26, 27, 28, 29, 30 to the pressure vessel 2. In general, nozzles are designed to achieve certain properties according to design parameters, such as thrust force, operating pressure and dimensions. The set of nozzles 3-14 is placed so that the lift system is able to deliver a thrust that has a force component opposed to the weight of the wing-in-ground effect vehicle 1. To achieve this the nozzles are mounted to discharge gas from the pressure vessel downwards relative to a nominal vehicle horizontal axis.

One or more of the nozzles may have gimbal mounts (not shown) which allow the nozzle thrust vector to be altered in relation to at least the horizontal axis during operation. Alternatively the thrust may be redirected by vanes (not shown) downstream of the nozzle.

[032J Six nozzles 3,4, 5, 6, 7, 8 and 9, 10, 11, 12, 13, 14 are placed symmetrically with half the nozzles being located on each side of the plane formed by the vertical and longitudinal axes of the wing-in ground effect vehicle 1. On each side, the six nozzles 3-8 and 9-14 are placed parallel to the longitudinal axis of the wing-in ground effect vehicle. Six nozzles 3, 4, 5, 9, 10, 11 are placed to the front (relative to the center of gravity of the wing-in-ground effect vehicle 1) of the wing-in-ground effect vehicle 1 and six nozzles 6, 7, 8, 12, 13, 14 are placed at the back of the wing-in-ground effect vehicle 1. The nozzles 3-14 axes are parallel to the vertical axis of the wing-in-ground effect vehicle 1. Air under pressure is held by the pressure vessel 2 and the pipes 17 and 18, to be delivered through the set of pipes 17, 18 and valves 19, 20, 21, 22. 23, 24, 25, 26, 27, 28, 29, 30. The compressed air is delivered at the top (inlet port) of the nozzles 3-14, when the valves 19-30 are opened. The nozzles 3-14 expel the jet of air downward to generate an upthrust.

[033] The set of valves 19-30 regulate the supply of air under pressure to the nozzles 3-14.

The set of valves 19-30 is regulated by a vehicle control system 31. The nozzles 3- 14 deliver a thrust produced by the jet of air flowing out of the nozzles 3-14. The lift system thrust is the force resulting from the thrusts delivered by the nozzles 3-14.

During the takeoff phase, the vehicle control system 31 regulates the set of valves 19-30 to provide a lift thrust that has a force component opposed to the weight of the wing-in-ground effect vehicle 1 with a magnitude greater than the weight of the wing-in ground effect vehicle 1. As a consequence, the lift system thrust provides an initial vertical acceleration to the wing-in-ground effect vehicle 1. The vehicle control system 31 regulates flow independently to each individual valve 19-30 to adjust the vertical acceleration and position, the pitch and roll angles of the wing-in-ground effect vehicle 1 during the operation of the lift system. The vehicle control system 31 receives input information from integrated accelerometers sensors and a controller 32, such as a joystick, manually operable by a pilot seated in seat 42.

[034] The wing in ground effect vehicle includes a main propulsion system intended to provide thrust directed rearwardly of the vehicle in normal horizontal flight. This system comprises a fan 33a driven by a motor 33d to induct air through vents 33b to the rear of the fuselage. The compressed air is discharged through a rear facing exhaust nozzle 33c.

[035] The lift system and the main propulsion system 33 of the wing-in-ground effect vehicle 1 are jointly operated during the takeoff phase during which the wing-in-ground effect vehicle 1 is above the ground. The lift system is operated for the purpose of takeoff until the wing-in-ground effect vehicle 1 reaches a forward velocity which is sufficient to fly from the wing-in-ground effect.

[038] An electric air compressor 34 is located inside the wing-in-ground effect vehicle fuselage 16. The electric air compressor 34 is powered by an electrical battery 35.

The electric air compressor 34 delivers compressed air to the pressure vessel 2 through a set of pipes 36, 37 and an air dryer 38 prior to the takeoff phase. The air dryer 38 removes the water vapor from the compressed air before the compressed air enters the pressure vessel 2. A pressure control system 39 regulates the electric air compressor 34 to adjust the air pressure in the pressure vessel 2. The pressure control system 39 receives input information from a vessel pressure sensor 40. The pressure vessel is equipped with a pressure relief valve 41.

[037] Although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims

CLAIMS1. A wing-in-ground effect vehicle having a lift system and a horizontal axis aligned with the horizontal during normal flight, said lift system comprising: a pressure vessel capable of holding fluid under pressure; a conduit communicating said pressure vessel with a nozzle said nozzle arranged to be capable of discharging said fluid down to provide a lift thrust with a force component opposed to the weight of the wing-in-ground effect vehicle.
2. A wing-in-ground effect vehicle according to claim 1, wherein the said conduit is one or more pipes.
3. A wing-in-ground effect vehicle according to claim 1 or claim 2, wherein a valve is disposed between the nozzle and the pressure vessel to control the discharge of fluid.
4. A wing-in-ground effect vehicle according to claim 3, wherein a valve is disposed between the conduit and each nozzle.
5. A wing-in-ground effect vehicle according to claim 3 or 4, wherein each valve is controlled by a vehicle control system.
6. A wing-in-ground effect vehicle according to any one of the preceding claims; wherein the nozzle is mounted on gimbals to provide thrust vectoring capability.
7. A wing-in-ground effect vehicle according to claim 5, wherein the said vehicle control system receives input from a manual command.
8. A wing-in-ground effect vehicle according to claim 5, wherein the said vehicle control system receives input information from a sensor.
9. A wing-in-ground effect vehicle according to claim 8, wherein the sensor is an accelerometer.
10. A wing-in-ground effect vehicle according to claim 8 or 9, wherein the sensor is a position sensor.
11. A wing-in-ground effect vehicle according to claim 10, wherein the said position sensor is a distance-to-ground sensor.
12. A wing-in-ground effect vehicle according to claim 8, wherein the sensor provides input information on the ground or water surface contours and obstacles to the said vehicle control system.
13. A wing-in-ground effect vehicle according to claim 12, wherein the vehicle control system operates the lift system from the input information provided by one of the sensors to avoid, or at least reduce or minimize, a collision with the ground surface or with an obstacle lying in the path of the said wing-in-ground effect vehicle.
14. A wing-in-ground effect vehicle according to claim 13 wherein the vehicle control system is: responsive to a sensor input to detect an obstruction in the path of the vehicle, responsive to detection of an obstruction to calculate a revised path, responsive to calculation of a revised path to control the lift system and a main propulsion system to direct the vehicle towards the revised path.
15. A wing-in-ground effect vehicle according to claim 14 wherein the vehicle control system is responsive to the calculation of a revised path to actuate a valve to open for a period and to a degree to deliver a determined charge of compressed fluid to a nozzle in order to direct the vehicle towards the revised path.
16. A wing-in-ground effect vehicle according to claim 1, wherein the fluid is compressed air.
17. A wing-in-ground effect vehicle according to claim 16, wherein the said compressed air is supplied by an air compressor located in the wing-in-ground effect vehicle.
18. A wing-in-ground effect vehicle according to claim 17, wherein the said air compressor is an electric motor driven air compressor powered by an electric battery located in the wing-in-ground effect vehicle.
19. A wing-in-ground effect vehicle according to claim 17, wherein the air compressor is an air compressor powered by a main motor of the wing-in-ground effect vehicle.
20. A wing-in-ground effect vehicle according to one of claims 17 to 19, wherein the said air compressor is regulated by a pressure control system.
21. A wing-in-ground effect vehicle according to claim 20, wherein the said pressure control system regulates the air compressor from the input information provided from a vessel pressure sensor, to maintain the pressure of the said compressed air inside the pressure vessel above a defined level.
22. A wing-in-ground effect vehicle according to claim 20 or 21, wherein the said pressure control system receives input information from a manual command.
23. A wing-in-ground effect vehicle according to one of claims 17 to 22, wherein the said compressed air goes through an air dryer to remove the water vapor from the compressed air before the said compressed air enters the pressure vessel.
24. A wing-in-ground effect vehicle according to any one of the preceding claims, wherein the pressure vessel is equipped with a pressure relief valve.
25. A wing-in-ground effect vehicle according to any one of the preceding claims, wherein there is more than one pressure vessel and at least one conduit communicating between each vessel to be able to convey fluid from one vessel to another.
26. A wing-in-ground effect vehicle according to claim 25, wherein a regulation system connects the pressure vessels through a pipe, a valve and the pressure control system.
27. A wing-in-ground effect vehicle according to any one of the preceding claims, wherein the fluid is generated through a chemical reaction, the chemical reaction is done through a regulation system connecting a vessel containing one or more chemical reactant substance to the pressure vessel through a pipe and a valve.
28. A wing-in-ground effect vehicle according to claim 27, wherein the regulation system includes a catalyst material mesh and the pressure control system.
29. A wing-in-ground effect vehicle according to any one of the preceding claims, wherein the pressure vessel is located inside a wing.
30. A wing-in-ground effect vehicle according to any one of the preceding claims, wherein the pressure vessel is inflatable.
31. A wing-in-ground effect vehicle according to any one of the preceding claims, wherein the nozzle is a convergent-divergent nozzle.
32. A wing-in-ground effect vehicle according to claim 5, wherein an extra nozzle in fluid communication with the pressure vessel by way of an extra valve, controlled by the vehicle control system and able to discharge compressed fluid from the pressure vessel directed other than down in order to expand the movement capabilities.
33. A wing-in-ground effect vehicle according to any one of the preceding claims, wherein a component is duplicated to provide redundancy.
34. A wing-in-ground effect vehicle according to claim 1 and as herein described with reference to the figures.