Ring-wing aircraft

• US 6,607,162 B2
• Filed: 02/07/2002
• Issued: 08/19/2003
• Est. Priority Date: 06/10/2000
• Status: Expired due to Fees

• Current Assignee: BAE Systems Plc
• Original Assignee: BAE Systems Plc
• Inventors: Henderson, James, Lock, Gary, Woods, Mike, Warsop, Clyde
• Primary Examiner(s): Swiatek, Robert P.
• Application Number:
  US10/049,044
• Publication Number:
  US 20020104923A1
• Time in Patent Office: 558 Days
• Field of Search: 244/12.6, 244/21, 244/23.C, 244/34.A, 244/36
• US Class Current: 244/12.6
• 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

A ring-wing aircraft 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 element (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 fuselage; and

a propulsion unit;

wherein

said fuselage is in the form of a ring-wing having a substantially circular cross-section defining a duct with a longitudinally-extending central axis, said propulsion unit being located within the duct and moveable aerofoils for controlling the aircraft in flight, the ring-wing fuselage being truncated obliquely at one end, such that a rear end of the aircraft, relative to a direction of horizontal flight, is truncated obliquely to form a ring-wing with opposed sides of unequal length, with a rear lower side extending beyond a rear upper side.

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

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

4. An aircraft according to claim 1, wherein at least one of components and any payload are housed in a compartment that is external to the longer side of the ring-wing fuselage.

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

6. An aircraft to claim 1, wherein components and payload are housed in a compartment provided within the longer side of the ring-wing fuselage.

7. An aircraft according to claim 1, wherein:

at least one of said aerofoils is a pitch controlling aerofoil; and

the pitch controlling aerofoil is positioned to reside substantially flat with the lower side of the ring-wing fuselage 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 fuselage.

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

10. An aircraft according to claim 1, which is unmanned.

11. An aircraft comprising:

a fuselage in the form of a ring-wing having a cross section defining a duct with a longitudinally extending central axis;

a propulsion unit located within the duct;

moveable air foils located within the duct for controlling the aircraft in flight;

wherein

the ring-wing fuselage is truncated at a rearward end thereof relative to direction of air flow through said duct, forming opposed portions of said ring-wing fuselage which are of unequal length, such that when said aircraft is in horizontal flight, a lower portion of said ring-wing fuselage extends farther rearwardly than an upper portion thereof.