GB2450386A

GB2450386A - Thrust reactive surface for positioning behind aircraft

Info

Publication number: GB2450386A
Application number: GB0717416A
Authority: GB
Inventors: Keith Edward Foster
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-06-20
Filing date: 2007-09-07
Publication date: 2008-12-24
Anticipated expiration: 2027-09-07
Also published as: GB2450386B; GB0717416D0; GB0711892D0

Abstract

A thrust reactive surface 1, for positioning behind an aircraft, comprises support means (such as a concrete wall 2) for supporting the reactive surface, such that a flow of rearwardly directed gas generated by the aircraft may be directed onto the reactive surface. It is stated that this develops forward momentum of the aircraft. The surface may be concave and comprise a plurality of ridges 4 or a plurality of surface units. Means may be provided for adjusting the curvature of the surface, and further means may be provided for pivoting the surface from a first position, in which it is housed in a runway recess, to a second position, in which it is substantially perpendicular to the runway. The surface may comprise tapering sidewalls 7, which may have deflectors 8, and may establish a vortex.

Description

Thrust Reactive Surface The present invention relates to a thrust

reactive surface for aircraft take-off and particularly, but not exclusively to a thrust reactive surface for efficient take-off of jet powered aircraft.

It is well known that jet powered aircraft take-off by applying power to the jet engines.

The jet engines take in air, burn fuel and compress the resultant gas which Is then ejected rearwardly at high speed. This ejection of compressed gas rearwardly of the aircraft produces a thrust which causes the aircraft to move forward.

Increasing the power to the aircraft engines creates more thrust and therefore causes the aircraft to accelerate more quickly toward the take-off speed. The take-off process requires a significant amount of power and thus fuel. Moreover, heavier aircrafts require longer runways to enable the aircraft to develop the necessary speed for take-off.

I have now devised a thrust reactive surface which enables an aircraft to take-off using less fuel and in a shorter distance.

In accordance with the present invention as seen from a first aspect, there is provided a thrust reactive surface for an aircraft, the thrust reactive surface comprising support means for supporting the reactive surface, such that rearwardly directed thrusted gas generated by the aircraft which is directed onto the reactive surface develops forward momentum of the aircraft.

Preferably, the thrust reactive surface is substantially arcuate.

By commencing aircraft take-off from in front of the thrust reactive surface, the aircraft is able to achieve a greater driving force and thus acceleration for a given thrust, and therefore achieve the required take-off speed more quickly than would be possible without the thrust reactive surface. Further, the substantially arcuate surface preferably establishes at least one circular flow of gas in front of the surface by virtue of the rearwardly directed gas being forced outwardly along the surface.

Preferably, the at least one circular flow of air comprises at least one vortex.

Preferably, the substantially arcuate surface comprises a plurality of ridges upstanding from the surface. The ridges are preferably orientated upon the surface such that the gas passing over the surface moves substantially perpendicularly to the ridges.

The ridges preferably further enhance the development of the at least one vortex by causing the rearwardly directed thrusted gas which passes closer to the surface to be re-directed in a circular path toward the centre of the surface more slowly than gas moving in a circular path further from the surface.

Preferably, the at least one vortex created by the arcuate surface further acts as a barrier, upon which rearwardly directed thrusted gas generated by the aircraft can be directed to further develop forward momentum of the aircraft Preferably, the arcuate surface comptises a substantially concave surface.

Preferably, the surface comprises a plurality of surface units, so that individual units can be replaced in the event that they become damaged.

Preferably, the support means comprises adjustment means which enables the degree of arc of the surface to be adjusted to accommodate different aircraft. -Preferably, the support means further comprises pivot means to enable the thrust reactive surface to be pivoted between a first position and a second position.

Preferably, in the first position the thrust reactive surface is housed within a recess formed within a runway and in the second position, the thrust reactive surface is substantially perpendicular to the runway.

The support means may preferably further comprise means which enable the thrust reactive surface to be repositioned at different positions on a runway, for example.

Preferably, the support means comprises a wall, a frame.

The thrust reactive surface preferably further comprises a pair of side walls which extend forwardly of the surface and which preferably taper down in height away from the surface.

The side walls preferably comprise at least one deflector to redirect gas moving away from the reactive surface in a circular path back to the reactive surface.

In accordance with the present invention as seen from a second aspect, there is provided a method of launching an aircraft, the method comprising the use of the thrust reactive surface of the first aspect.

Preferably, the aircraft is a jet powered aircraft.

The preferred embodiments of the present invention will now be described by way of example only and with reference to the accompanying drawings, in which: Figure 1 is a perspective view of the thrust reactive surface of the present invention; Figure 2 is a plan view of the thrust reactive surface of the present invention; FIgure 3 is a sectional view taken along line A-A of figure 2; Figure 4 is a front view of the thrust reactive surface of the present invention; and, Figure 5 is a sectional view taken along line B-B of figure 3.

Referring to figures 1 to 3 there is shown a thrust reactive surface I in accordance with the present invention. The thrust reactive surface I is substantially concave and is formed against a wall 2, which may by constructed from concrete, upon which a jet powered aircraft 3 may direct the thrust developed by the jet engines (not shown).

The wall 2 comprises a plurality of replaceable surface units (not shown) so that worn or damaged units can be removed and replaced without having to replace the entire surface 1. The waIl 2 is adjustable via adjustment means (not shown) so that the degree of arc of the surface I can be varied to capture the thrusted exhaust gas ejected from different sized aircraft 3.

The arcuate shape of the surface I causes the thrusted gas directed upon the surface 1 to circulate radially outwardly from the centre of the surface I and then curve around in front of the surface I in a circular manner back to the centre of the surface I. The surface I is provided with a plurality of ridges 4 as shown in figures 4 and 5 which are formed within the surface I and which are orientated such that the thrusted gas which passes over the surface I moves substantially perpendicularly to the ridges 4. The ridges 4 act to impede the flow of gas which passes close to the reactive surface 1. Gas moving around the surface I, but displaced away from the surface I wifi not experience so much flow impedance and therefore will move faster. The surface 1 together with the ridges 4, therefore encourage the development of a vortex 5.

In use, the aircraft 3 effectively pushes against the thrust reactive surface I upon accelerating along a runway 6. The vortex 5 created by the swirl of thrusted gas creates a pressurised volume of gas in front of the surface 1. Accordingly, as the aircraft 3 moves away from the surface, the pressurised volume of gas further acts as a barrier to the thrusted gas and thus further helps to develop the forward momentum of the aircraft 3 in moving along the runway 6. In this manner, the aircraft 3 is able to achieve greater acceleration with less power and thus achieve the required take-off speed more quickly, than would be possible without the thrust reactive surface I. Extending forwardly of the reactive surface I from each side thereof, there is provided a side wall 7 which tapers down in height away from the wall 2. The side walls 8 may preferably comprise a series of deflectors 8 which act to redirect the thrusted gas in a circular motion back toward the centre of the surface I. The waIl 2 supporting the thrust reactive surface I may further comprise pivot means (not shown) which enables the waIl 2 and thus the surface 1 to be pivoted between a position in which the surface is held within a recess (not shown) formed within the runway 6 and a position in which the wall and thus reactive surface I is substantially perpendicular to the runway 6. Accordingly, when the reactive surface I is not required it can be lowered into the recess.

Alternatively, or in addition, the wall 2 may comprises a lockable wheel base (not shown), or the wall 2 may be mounted to a track (not shown). In this manner, the wall 2 and thus thrust reactive surface I may be repositioned at different positions along a runway 6 or removed from a runway 6 following take-off of an aircraft 3, to enable a subsequent aircraft to safely land on the same runway 6.

From the foregoing therefore it is to be appreciated that the thrust reactive surface I reduces the amount of -fuel consumed during aircraft 3 take-off and also enables the aircraft 3 to take-off over a shorter distance, since the aircraft 3 can achieve a greater acceleration for a given thrust.

Claims

Claims 1. A thrust reactive surface for an aircraft, said thrust

reactive surface comprising support means for supporting said reactive surface, such that rearwardly directed thrusted gas generated by the aircraft which is directed onto said reactive surface develops forward momentum of the aircraft.
2. A thrust reactive surface according claim 1, wherein said thrust reactive surface is substantially arcuate.
3. A thrust reactive surface according claim 2, wherein the substantially arcuate surface establishes at least one circular flow of gas in front of the surface by virtue of the rearwardly directed gas being forced outwardly along the surface.
4. A thrust reactive surface according claim 3, wherein said at least one circular flow of air comprises at least one vortex.
5. A thrust reactive surface according to any of claims 2 to 4. wherein said substantially arcuate surface comprises a plurality of ridges upstanding from the surface.
6. A thrust reactive surface according to claim 5, wherein the ridges are orientated upon the surface such that the gas passing over the surface moves substantially perpendicularly to the ridges.
7. A thrust reactive surface according to any of claims 3 to 6, wherein the at least one circular flow of gas acts as a barrier, upon which rearwardly directed thrusted gas generated by the aircraft can be directed to further develop forward momentum of the aircraft.
8. A thrust reactive surface according to any of claims 2 to 7, wherein the arcuate surface comprises a substantially concave surface.
9. A thrust reactive surface according to any preceding claim, wherein the surface comprises a plurality of surface units.
10. A thrust reactive suiface according to any preceding claim, wherein the support means comprises adjustment means which enables the degree of arc of the surface to be adjusted to accommodate different aircraft.
11. A thrust reactive surface according to any preceding claim, wherein the support means further comprises pivot means to enable the thrust reactive surface to be pivoted between a first position and a second position.
12. A thrust reactive surface according to claim 11, wherein in the first position the thrust reactive surface is housed within a recess formed within a runway and in the second position, the thrust reactive surface is substantially perpendicular to the runway.
13. A thrust reactive surface according to any preceding claim, wherein the support means comprises means which enable the thrust reactive surface to be repositioned at different positions.
14. A thrust reactive surface according to any preceding claim, wherein the support means comprises a wall.
15. A thrust reactive surface according to any preceding claim, further comprising a pair of side walls which extend forwardly of the surface.
18. A thrust reactive surface according to claim 15, wherein the side walls taper down in height away from the surface.
17. A thrust reactive surface according to claim 15 or 16, wherein the side walls further comprise at least one deflector to redirect gas moving away from the reactive surface in a circular path back to the reactive surface.
18. A thrust reactive surface according to any preceding claim, wherein the aircraft is a jet powered aircraft.
19. A method of launching an aircraft, the method comprising the use of the thrust reactive surface of any preceding claim.
20. A thrust reactive surface substantially as herein described with reference to the accompanying drawings.
21. A method of launching an aircraft substantially as herein described with reference to the accompanying drawings.