GB2209314A - Lifting arrangement by direct thrust of the engine flow to vertical take-off aircraft - Google Patents

Description

LIFTING ARRANGEMENT BY DIRECT THRUST OF THE ENGINE FLOW TO VERTICAL TAKE-

OFF AIRCRAFT P+ 220931A The present invention relates to a lifting arrangement by direct action of the engine thrust to vertical take-off aircraft. This arrangement permits vertical take-off and totally or partially provides the lift during the horizontal flight by direct thrust of the engines.

Accordingly the present invention provides a vertical take-off aircraft having at least one engine directing air into an opening in the aircraft, the opening having its centroid located over the aircraft centre of gravity, and means to direct the engine air so as to counteract each of the aircraft weight and the total drag force.

The geometry or camber of the wings may if required be modified to change the angle of attack in order to produce the lift during forward flight.

The invention allows the engine thrust to directly without the wings. The applied force axis vector has the same magnitude, line of action, and direction as the result of the vectorial sum of the forces experienced in operation and is therefore equal and opposite to the result of the sum of the weight and total drag to be overcome in flight.

The forces can be also applied independently, one to counteract the weight and the other the total drag.

The engines may be of the ducted fan type, e.g. a turbofan (M) with an ultrahigh bypass ratio or with an ultralow bypass ratio, or an unducted fan (UDF) i.e. a propeller type without a duct, using a turboprop or a separate engine driving a propeller although this offers less efficiency.

The engine fans or propellers must be fitted at the upper side of the aircraft and over the centre of be used or - 2 gravity so that the thrust delivers a large stability to balance the nose up pitching motion. If several engines are in operation they should be as close as possible to one another and over the centre of gravity. The engines may be 5_ tilting fan or moving nozzle type.

The engines may rotate around the aircraft transverse axis, operated by hydraulic rams, or by electric or hydraulic motors with a gearing system. A gill at the upper rear side of the cowl improves the engine performance.

When several engines are used some of them may be fixed along the resulting line of action of the thrust and lift vectors in forward flight. Consequently a vane is required behind and below the engine(s) in order to divert the air flow during vertical take-off, or a fan or moving nozzle may be fitted to control the aircraft pitching. A smooth tilting may be reached using an asymmetric power. 20 The air conditioning, air for defrosting, hydraulic pressure and electric supply will be readily obtained from the fixed engines. It may be convenient to displace the centre of gravity for a better efficiency during forward flight. 25 The aircraft wings are only used as stabilizers and their lift will be altered by increasing the angle of attack or modifying the camber by means of flaps, horizontal stabilizers, etc. It is therefore convenient for the centre of pressure resulting from all the area to be slightly displaced during horizontal travel. The point of the application of the total drag will have to be displaced with regard to the centre of gravity and at the thrust application point.

Vanes radial to the engine-driven air flow and having up to four functions counteract the engine rotation torque and they can be used for control and stability in "A i f 1 low speed forward flight or vertical flight. Therefore some of them may be movable to rotate around their respective axes to control the air direction.

If only the vanes on the aircraft transverse axis 5- are rotated, and in the same sense, they control pitching. If only in the vanes on the longitudinal axis are rotated they will control yaw. One of the most foreward vanes may project below the lower surface of the aircraft and thus it may control the direction in horizontal flight.

The displacement of the centre of gravity may help stabilization during the climb.

The stability may be controlled by means of gyroscopes.

In forward flight yawing, pitching and rolling are controlled in a conventional way.

The vector resulting from the lift of the wing when the flaps (which may be the leading edge and/or trailing edge types) are extended, must be close to the centre of gravity.

For forward flight a further engine may be fitted in any place of the aircraft but preferably in the forward area to obtain better stability.

The climb or descent is controlled by power when there is a short horizontal displacement; the climb with engine tilting or acting in the rudder in addition to the use of variable power may be checked with horizontal speed.

The wing effect may be used in the descent to achieve the lift in order to save the use of the engines until the landing is near.

The area where the air or gases flow is to be clear. Consequently, in some cases the rear part of the aircraft is divided in two halves with the flow passing inside. In other cases it is enough for the central area at the rear to be empty and clear.

The centre of gravity is held or shifted by means of pumping the fuel load.

The service connections to the tilting engines will be suitably flexible and it will be sheathed or protected if desired by the interior of the mounting shaft.

From the above, it will be appreciated that the 5- invention shows the following improvements with regard to the presently known technique of vertical take-off:

If one of the engines stops the stability is such that there is no large overturning torque.

- The aircraft may land and take-off in any place intended for vehicles in motion. This is very important if a failure occurs.

It may land and take-off at low speed in a conventional or in a mixed way.

- The landings are very smooth.

is - The landing gear can be very light.

- The landings and take-offs are less dangerous because of the low speed.

- The lift power required in taking-off and landings is only one third of the total power. In conventional aircraft it is also necessary for the required power to overcome the total drag which is specially high during take-off mainly due to the increase in induced drag resulting when the flaps are extended or when the angle of attack increases.

Flaps are not necessary although they may be used in an emergency.

- The aircraft does not need any ILS or ground control.

The operations are quicker. There is less risk of collision.

- The wind does not represent any problem during the landings and takingoffs in small confined areas.

- The impact with birds is less likely because of the low speed of motion at low altitude, and the impact is less critical.

g A 0 1 The aircraft may land and take-off with visibility with less difficulty.

Refuelling may be carried out in flight very easily since the aircraft is stable at low speeds, 5_ permitting take-off with less weight and then refuelling in flight by periods with which there is an important saving.

The performance is better since there is no induced drag because the wings are not used to produce the lift. The aircraft is also lighter and therefore fuel costs are lower too.

The invention is explained below, by way of example, with reference to the accompanying drawings in which:- FIGURE 1 shows the arrangement of an engine fitted in the aircraft with the appropriate tilting for lifting and for horizontal flight; FIGURE 2 shows an aircraft just at the moment of the taking-off or landing; FIGURE 3 shows an arrangement with three engines at the moment of the vertical take-off with the rear area open to the engines; FIGURE 4 shows an arrangement where the free or hollow part is only in the centre of the aircraft and behind the engines, with the engines in operation ready for vertical flight; FIGURE 5 shows a solution where the area above all the bottom surface of the wing is for the passengers; the engines are in position appropriate to horizontal flight and some of them may always be in that position; 30 FIGURE 6 shows another solution of the invention applied to a tailless aircraft, where the tilting arrangement also shifts the centre of gravity; FIGURE 7 shows a fixed turbofan engine with means to vector its flow to correspond to lift and forward thrust; and 1 FIGURE 8 shows a variably tiltable turbine.

i -.6 - As has been already mentioned, Figure 1 shows the assembly of an engine 1 in an aircraft 2 with an appropriate tilting to give the lift and horizontal thrust.

In Figure 1, the vector W is the weight. Vector D is the total drag. Vector T is the thrust to counteract the weight and the drag and shows the direction and sense in which the thrusting power has to be applied.

The cavity 3 permits the air or other thrust gases to flow through the aircraft body and downwards.

Figure 2 shows an aircraft during landing or take-off where vector W has to be overcome. Vanes 4, only three of which may be seen, are radial to the engine and provide the control around the three main axes of the aircraft. That Figure also shows the lift vector L.

Figure 3 shows an arrangement with three engines just at the moment of vertical travel with the rear area facing the engines open. The drawing also shows the vertical stabilizer 5, the rudder control 6, the elevator 7, and the ailerons 8.

Figure 4 shows a solution where the free or hollow part is sited in the centre of the aircraft and to the rear of the engines. The engines are ready for vertical flight. The wing flaps or elevators are shown at 9.

Figure 5 shows a solution where the area above all the lower surface of the aircraft is used for housing the passengers. The engines are ready for horizontal flight and some of them may be fixed in that position.

Figure 6 shows another solution of the invention where the driving arrangement is applied to a tailless aircraft and also displaces the centre of gravity.

Figure 7 shows a turbofan engine with a fixed inclination to provide the lift and forward thrust. Vane 11 at the rear is movable to direct the air or gas flow to establish vertical thrust. The tilting of vane 11 is achieved by ram 12. The aircraft structure is represented v at 13. The steering control vane 14 operates on the turbine or fan outflow. The shaft 15 is tilted about 45 0 and protrudes below the bottom fuselage area and it may also operate as steering control in horizontal flight. The engine is supported on a bracket 16 to the aircraft, and the service connections between the engine and aircraft may be fitted within the interior 17 of this bracket.

Finally, Figure 8 shows a turbine variably tiltable in the bracket 19 around the axis 18 by means of the bearing 20 and operated by the gear 21. The electric systeme hydraulic and pneumatic installations, etc. may be accommodated within the hollow shaft 22. 23 illustrates to the aircraft internal surface.

Having described the nature of the invention as well as how to put it into practice, it is necessary to indicate that the invention is not limited to the aforementioned arrangements shown in the drawings but may be modified in detail without departing from the scope of the following claims.

Claims (7)

C L A I M S

1. A vertical take-off aircraft having at least one engine directing air into an opening in the aircraft, the opening having its centroid located over the aircraft centre of gravity, and means to direct the engine air so as to counteract each of the aircraft weight and the total drag force.

2. An aircraft according to claim 1, wherein the said at least one engine is fixed in the aircraft and a vane is provided to divert the air or gas flow thereof.

3. An aircraft according to claim 1, wherein the engine is fixed in the aircraft and has a tiltable nozzle or fan to direct the air or gas flow.

4. An aircraft according to claim 1, wherein the engine is tiltably mounted in the aircraft by means of a shaft journalled in the aircraft structure and tilting is operated by a gear transmission.

5. An aircraft according to any one of claims 1 to 4, wherein the engine is a jet engine and is associated with straightener vanes radial to the airflow generated in use of the engine, for counteracting the engine rotation torque and for allowing the control and stability at low speed or vertical flight.

6. An aircraft according to claim 5, wherein at least some of said straightener vanes are rotatably adjustable to control said airflow generated by the engine.

7. A vertical take-off aircraft constructed and adapted to operate substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawings.

Published 1988 at The Patent Offce. State House. 66 71 Hign Holborn. Lo,Or. WC1R 4TP. Further copies may be obtained from The Patent Office, Sales BrancII.. St. Ma-. Cray. Orpington. Kent BR5 3RD. Printed by Multiplex techniques ltd. St Mary Cray, Kent. Con. D87.

f