Ring-wing aircraft

• US 20020104923A1
• Filed: 02/07/2002
• Published: 08/08/2002
• Est. Priority Date: 06/10/2000
• Status: Active Grant

• Current Assignee: BAE Systems Plc
• Original Assignee: BAE Systems Plc
• Inventors: Henderson, James, Lock, Gary, Woods, Mike, Warsop, Clyde
• Granted Patent: US 6,607,162 B2
• Time in Patent Office: Days
• US Class Current: 244/34A
• CPC Class Codes: B64C 39/062 having annular wings
• CPC Class Codes: B64U 10/25 Fixed-wing aircraft VTOL aircraft B64U10/20
• CPC Class Codes: B64U 50/14 ducted or shrouded
• CPC Class Codes: B64U 50/19 using electrically powered motors
• CPC Class Codes: B64U 50/30 Supply or distribution of electrical power

Abstract

This invention relates to ring-wing aircraft and is suited particularly, although not exclusively, to use in micro-unmanned air vehicles (UAV'"'"'s) with ring-wings.

An aircraft (10) according to the invention comprises a ring-wing (11) defining a duct (16) with a longitudinally-extending central axis (31), propulsion means (15) located within the duct and moveable aerofoils (13, 18) for controlling the aircraft in flight, the ring-wing being truncated obliquely at one end, that end being the rear (11b) when in horizontal flight, to form a ring-wing with opposed sides of unequal length. This arrangement produces center of mass offset from the central axis of the ring-wing, the pendulum effect will ensure that the aircraft will roll so that its center of mass will always be at the lowest height possible when the aircraft is airborne. Therefore the aircraft has a preferred orientation, and the control surfaces can be oriented with respect to this preferred orientation. In addition, the oblique truncation at the rear keeps the center of mass towards the front of the aircraft thereby giving improved stability in all three axes.

Claims

1. An aircraft comprising a ring-wing of substantially circular cross-section defining a duct with a longitudinally-extending central axis, a propulsion means located within the duct and moveable aerofoils for controlling the aircraft in flight, the ring-wing being truncated obliquely at one end, that end being the rear when in horizontal flight, to form a ring-wing with opposed sides of unequal length.

2. An aircraft according to claim 1, wherein the ring-wing is truncated by a planar slice through the ring-wing.

3. An aircraft according to claim 1, wherein the ring-wing is truncated by a curved slice, the angle made with the ring-wing being relatively shallow at the longer side of the ring-wing and relatively steep at the shorter side of the ring-wing.

4. An aircraft according to any preceding claim, wherein components and/or any payload are housed in a compartment that is external to the longer side of the ring-wing.

5. An aircraft according to any preceding claim, wherein components and/or any payload are housed in a compartment provided within the longer side of the ring-wing.

6. An aircraft according to claim 4 or claim 5, wherein the compartment is provided at an end of the ring-wing, that end being the front when in horizontal flight.

7. An aircraft according to any preceding claim, wherein the pitch controlling aerofoil is positioned to reside substantially flat with the lower side of the ring-wing when not deployed.

8. An aircraft according to claim 7, wherein the pitch-controlling aerofoil is provided as an element of the longer side of the ring-wing.

9. An aircraft according to claim 7 or claim 8, further comprising two orthogonal vanes, wherein one vane provides aerodynamic lift in the same direction as the pitch-controlling aerofoil.

10. An aircraft according to any preceding claim which is unmanned.