WO2017129953A1

WO2017129953A1 - A wing-in-ground effect vehicle having a lift system

Info

Publication number: WO2017129953A1
Application number: PCT/GB2017/050153
Authority: WO
Inventors: Gonzague LERUTH
Original assignee: Exclin Ltd
Priority date: 2016-01-27
Filing date: 2017-01-20
Publication date: 2017-08-03
Also published as: GB2531468B; GB2531468A; GB201601534D0

Abstract

Wing-in-ground effect vehicle (1) having a lift system with a pressure vessel (2) and a set of nozzles (3-14). 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 and may be regulated by a valve (19-30) which is controlled by a vehicle control system (31). Compressed fluid from the pressure vessel is discharged through the nozzles on operation of a valve by the vehicle control system to levitate the vehicle and allow the main propulsion system (33) 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 thrust that increases the vehicle clearance from the ground or water, or modifies the vehicle roll and pitch angles.

Description

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

Technical Field

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

A wing-in-ground effect vehicle is a vehicle that attains level flight near the ground or water surface 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.

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

Background Art

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.

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.

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.

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.

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

Disclosure of Invention

Accordingly the present invention provides a wing-in-ground effect vehicle having a lift system as defined in claim 1.

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.

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 vapour 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.

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. 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 means to rotate the lift nozzle, for example the nozzle may be mounted on a gimbal.

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.

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

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 of a hangar.

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

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.

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.

A vehicle control system is typically used to regulate one or more valves located between the or each pressure vessel and the or 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.

The or each pressure vessel is filled with a fluid, such as air. The or each pressure vessel is pressurized before or during flight. The or each pressure vessel may be filled and pressurized during flight, typically with at least one air compressor (34) located in the wing-in-ground effect vehicle.

The air compressor (34) may be an electric air compressor (34) powered by an electric battery or a mechanical air compressor (34) typically powered by an engine or turbocharger of the wing-in-ground effect vehicle. The air compressor (34) may be regulated by a pressure control system (39). The pressure control system (39) typically receives input information from a sensor such as a vessel pressure sensor (40) or from a manual command. The compressed air generated by the air compressor (34) may typically go through an air dryer (38) to remove the water vapour from the compressed air before the compressed air enters the pressure vessel. The pressure vessel may be equipped with a pressure relief valve.

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 (39). 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 catalyse the reaction. The regulation system may also include a pressure control system (39).

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

The one or more pressure vessel may be inflatable, i.e. of variable volume to expand or contract as it is inflated or deflated.

The lift nozzles may be convergent-divergent nozzles.

Extra manoeuvring 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, manoeuvring 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 manoeuvring 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.

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 Drawings

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

Best Mode for Carrying Out the Invention

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. A fixed ground effect wing 15 is 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.

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 centre 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 axes of the nozzles 3-14 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.

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 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.

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.

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.

An electric air compressor (34) 34 is located inside the wing-in-ground effect vehicle fuselage 16. The electric air compressor (34) 34 is powered by an electrical battery 35. The electric air compressor (34) 34 delivers compressed air to the pressure vessel 2 through a set of

pipes

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

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

Claims

A wing-in-ground effect vehicle having a lift system, characterised in that said lift system comprises: a pressure vessel (2) holding fluid under pressure; a conduit communicating said pressure vessel (2) with a nozzle (3-14) said nozzle (3-14) arranged to be capable of discharging said fluid down to provide a lift thrust.
A wing-in-ground effect vehicle according to claim 1, wherein the said conduit is one or more pipes (17,18).
A wing-in-ground effect vehicle according to claim 1 or claim 2, wherein a valve (19-30) is disposed between the nozzle (3-14) and the pressure vessel (2) to control the discharge of fluid.
A wing-in-ground effect vehicle according to claim 3, wherein a valve (19-30) is disposed between the conduit and at least one nozzle (3-14).
A wing-in-ground effect vehicle according to claim 3 or 4, wherein at least one valve (19-30) is controlled by a vehicle control system (31).
A wing-in-ground effect vehicle according to anyone of the preceding claims; wherein the nozzle (3-14) is mounted on gimbals to provide thrust vectoring capability.
A wing-in-ground effect vehicle according to claim 5, wherein the said vehicle control system (31) receives input from a manual command.
A wing-in-ground effect vehicle according to claim 5, wherein the said vehicle control system (31) receives input information from a sensor.
A wing-in-ground effect vehicle according to claim 8, wherein the sensor is an accelerometer.
A wing-in-ground effect vehicle according to claim 8, wherein the sensor is a position sensor.
A wing-in-ground effect vehicle according to claim 10, wherein the said position sensor is a distance-to-ground sensor.
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 (31).
A wing-in-ground effect vehicle according to claim 12, wherein the vehicle control system (31) 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.
A wing-in-ground effect vehicle according to claim 13 wherein the vehicle control system (31) 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.
A wing-in-ground effect vehicle according to claim 14 wherein the vehicle control system (31) is responsive to the calculation of a revised path to actuate a valve (19-30) to open for a period and to a degree to deliver a determined charge of compressed fluid to a nozzle (3-14) in order to direct the vehicle towards the revised path.
A wing-in-ground effect vehicle according to claim 1, wherein the fluid is air.
A wing-in-ground effect vehicle according to claim 16, wherein the compressed air is supplied by an air compressor (34) located in the wing-in-ground effect vehicle.
A wing-in-ground effect vehicle according to claim 17, wherein the said air compressor (34) is an electric motor driven air compressor (34) powered by an electric battery located in the wing-in-ground effect vehicle.
A wing-in-ground effect vehicle according to claim 17, wherein the air compressor (34) is an air compressor (34) powered by a main motor (33d) of the wing-in-ground effect vehicle.
A wing-in-ground effect vehicle according to one of claims 17 to 19, wherein the said air compressor (34) is regulated by a pressure control system (39).
A wing-in-ground effect vehicle according to claim 20, wherein the said pressure control system (39) regulates the air compressor (34) from the input information provided from a vessel pressure sensor (40), to maintain the pressure of the compressed air inside the pressure vessel (2) above a defined level.
A wing-in-ground effect vehicle according to claim 20 or 21, wherein the said pressure control system (39) receives input information from a manual command.
A wing-in-ground effect vehicle according to one of claims 17 to 22, wherein the compressed air goes through an air dryer (38) to remove the water vapor from the compressed air before the compressed air enters the pressure vessel (2).
A wing-in-ground effect vehicle according to anyone of the preceding claims, wherein the pressure vessel (2) is equipped with a pressure relief valve (19-30).
A wing-in-ground effect vehicle according to anyone of the preceding claims, wherein there is more than one pressure vessel (2) and at least one conduit communicating between each vessel to be able to convey fluid from one vessel to another.
A wing-in-ground effect vehicle according to claim 25, wherein a regulation system connects the pressure vessels (2) through a pipe, a valve (19-30) and the pressure control system (39).
A wing-in-ground effect vehicle according to anyone 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 (2) through a pipe and a valve (19-30).
A wing-in-ground effect vehicle according to claim 27, wherein the regulation system includes a catalyst material mesh and the pressure control system (39).
A wing-in-ground effect vehicle according to anyone of the preceding claims, wherein the pressure vessel (2) is located inside a wing.
A wing-in-ground effect vehicle according to anyone of the preceding claims, wherein the pressure vessel (2) is inflatable.
A wing-in-ground effect vehicle according to anyone of the preceding claims, wherein the nozzle (3-14) is a convergent-divergent nozzle (3-14).
A wing-in-ground effect vehicle according to claim 5, wherein an extra nozzle (3-14) in fluid communication with the pressure vessel (2) by way of an extra valve (19-30), controlled by the vehicle control system (31) and able to discharge compressed fluid from the pressure vessel (2) directed other than down in order to expand the movement capabilities.
A wing-in-ground effect vehicle according to anyone of the preceding claims, wherein a component is duplicated to provide redundancy.