
The Demon is an experimental
unmanned aerial vehicle
An unmanned aerial vehicle (UAV) or unmanned aircraft system (UAS), commonly known as a drone, is an aircraft with no human pilot, crew, or passengers onboard, but rather is controlled remotely or is autonomous.De Gruyter Handbook of Dron ...
(UAV) developed and manufactured by British defence conglomerate
BAE Systems
BAE Systems plc is a British Multinational corporation, multinational Aerospace industry, aerospace, military technology, military and information security company, based in London. It is the largest manufacturer in Britain as of 2017. It is ...
. It has been referred to as being the world's first "
flapless" aircraft.
The Demon was developed as a demonstrator for the ''flapless air vehicle integrated industrial research'' (FLAVIIR) programme. Developed from the conventional BAE Systems Eclipse UAV, it was used to trial an unconventional
aircraft flight control system
A conventional Fixed-wing aircraft, fixed-wing aircraft flight control system (AFCS) consists of flight control surfaces, the respective cockpit controls, connecting linkages, and the necessary operating mechanisms to control an aircraft's di ...
over the course of two years. Various other technologies were also experimented with, including
modular and cost-reduction techniques. On 17 September 2010, the Demon conducted its first flight without using any conventional flight control surfaces. It has been speculated that the technology has potential applications in both civilian and military aviation.
Development
During the early 21st century, British defence conglomerate
BAE Systems
BAE Systems plc is a British Multinational corporation, multinational Aerospace industry, aerospace, military technology, military and information security company, based in London. It is the largest manufacturer in Britain as of 2017. It is ...
initiated a five-year research programme known as ''flapless air vehicle integrated industrial research (FLAVIIR)''.
This effort had a declared budget of £6.5 million, which was financed by both BAE Systems and the UK's Engineering and Physical Sciences Research Council.
It had the aim of developing and testing a new
aerodynamic
Aerodynamics () is the study of the motion of atmosphere of Earth, air, particularly when affected by a solid object, such as an airplane wing. It involves topics covered in the field of fluid dynamics and its subfield of gas dynamics, and is an ...
circulation-based
aircraft flight control system
A conventional Fixed-wing aircraft, fixed-wing aircraft flight control system (AFCS) consists of flight control surfaces, the respective cockpit controls, connecting linkages, and the necessary operating mechanisms to control an aircraft's di ...
, manipulating airflow via non-traditional means; unlike most prior efforts, it sought to bring technologies together to form a functional system rather than develop isolated elements. Participants in the programme included various British aeronautics companies, specialists, and academic institutions included
Cranfield University
Cranfield University is a postgraduate-only public research university in the United Kingdom that specialises in science, engineering, design, technology and management. Cranfield was founded as the College of Aeronautics (CoA) in 1946. Throug ...
and nine other British universities.
["Developing the next generation of Unmanned Aerial Vehicles (UAVs) with BAE Systems."](_blank)
''Cranfield University'', Retrieved: 6 July 2019.["Flaviir project trials new forms of wing command."](_blank)
''The Engineer'', 11 July 2010.
During August 2007, an American patent was filed for elements of this new control system concept; it was granted during July 2011. As development proceeded, it was decided to produce an experimental unmanned air vehicle to demonstrate manoeuvring without the aid of conventional
flight control surfaces
Flight control surfaces are aerodynamic devices allowing a pilot to adjust and control the aircraft's flight attitude. The primary function of these is to control the aircraft's movement along the three axes of rotation. Flight control surfaces ...
. The conventional BAE Systems Eclipse was selected as the basis for the demonstrator.
Ahead of the flight test programme, it was subjected to various ground-based tests, including the use of
wind tunnel
A wind tunnel is "an apparatus for producing a controlled stream of air for conducting aerodynamic experiments". The experiment is conducted in the test section of the wind tunnel and a complete tunnel configuration includes air ducting to and f ...
s and scale models.
[Coppinger, Rob]
"Ground trials start for UK vectored thrust prototype UAV."
''Flight International'', 2 October 2009.
The Demon participated in a two-year demonstration programme, during which the team studied the UAV's performance throughout its flight envelope.
On 17 September 2010, the Demon performed its first flight in which all of its conventional control surfaces were deactivated during a portion of the flight off the coast of
Cumbria
Cumbria ( ) is a ceremonial county in North West England. It borders the Scottish council areas of Dumfries and Galloway and Scottish Borders to the north, Northumberland and County Durham to the east, North Yorkshire to the south-east, Lancash ...
, having flown out of
Barrow/Walney Island Airport.
["BAE’s flapless UAV is breath of fresh air."](_blank)
''Institution of Mechanical Engineers
The Institution of Mechanical Engineers (IMechE) is an independent professional association and learned society headquartered in London, United Kingdom, that represents mechanical engineers and the engineering profession. With over 110,000 member ...
'', 6 October 2010.["Showcase UAV demonstrates 'Flapless Flight'."](_blank)
''phys.org'', 27 September 2010. Richard Williams, BAE's programme director for future capability, stated of the occasion: "I feel sure I have witnessed a significant moment in aviation history".
In late 2010, BAE Systems stated that the Demon shall not be followed up by a direct production aircraft, but its technologies would be filtered through to other platforms instead.
[Ford, Jason]
"MAGMA jet-powered UAV sets course for flapless flight."
''The Engineer'', 14 December 2017. Aerospace periodical
Flight International
''Flight International'', formerly ''Flight'', is a monthly magazine focused on aerospace. Published in the United Kingdom and founded in 1909 as "A Journal devoted to the Interests, Practice, and Progress of Aerial Locomotion and Transport", i ...
speculated that this unique circulation control system could one day be employed in civilian aviation to reduce the size of the wing on widebody
airliners
An airliner is a type of airplane for transporting passengers and air cargo. Such aircraft are most often operated by airlines. The modern and most common variant of the airliner is a long, tube shaped, and jet powered aircraft. The largest o ...
.
Its developers have stated their hopes that the new technology could be used to reduce noise, cut fuel consumption, and lower maintenance costs. In terms of military applications, the technology might enable future combat aircraft to achieve greater levels of
stealth than conventionally equipped counterparts.
Design
The BAE Systems Demon is an experimental
unmanned aerial vehicle
An unmanned aerial vehicle (UAV) or unmanned aircraft system (UAS), commonly known as a drone, is an aircraft with no human pilot, crew, or passengers onboard, but rather is controlled remotely or is autonomous.De Gruyter Handbook of Dron ...
(UAV). In terms of its basic configuration, it is a
blended wing-body aircraft, possessing an approximate wingspan of 8-foot (2.5m) and a weight of 200 lb (90 kg).
In flight, it could attain a maximum speed of 150 kn. It was outfitted with a conventional
flap-based flight control system which can be switched on and off during flight, allowing the aircraft to alternate between its experimental and conventional control system.
The Demon was built to flight test a novel aerodynamic control system. This system uses a combination of engine
exhaust gas
Exhaust gas or flue gas is emitted as a result of the combustion of fuels such as natural gas, gasoline (petrol), diesel fuel, fuel oil, biodiesel blends, or coal. According to the type of engine, it is discharged into the atmosphere through ...
, which is redirected using a
thrust vectoring
Thrust vectoring, also known as thrust vector control (TVC), is the ability of an aircraft, rocket or other vehicle to manipulate the direction of the thrust from its engine(s) or motor(s) to Aircraft flight control system, control the Spacecra ...
nozzle, and
bleed air
Bleed air in aerospace engineering is compressed air taken from the compressor stage of a gas turbine, upstream of its fuel-burning sections. Automatic air supply and cabin pressure controller (ASCPC) valves bleed air from low or high stage engine ...
, which is precisely controlled to provide control over the same aerodynamic forces that would be traditionally provided by numerous
flight control surfaces
Flight control surfaces are aerodynamic devices allowing a pilot to adjust and control the aircraft's flight attitude. The primary function of these is to control the aircraft's movement along the three axes of rotation. Flight control surfaces ...
, including flaps,
aileron
An aileron (French for "little wing" or "fin") is a hinged flight control surface usually forming part of the trailing edge of each wing of a fixed-wing aircraft. Ailerons are used in pairs to control the aircraft in roll (or movement aroun ...
s and
elevators
An elevator (American English) or lift (English in the Commonwealth of Nations, Commonwealth English) is a machine that vertically transports people or freight between levels. They are typically powered by electric motors that drive tracti ...
.
Termed ''
fluidic flight controls'', the arrangement used on the Demon reportedly functions by directing air from a rectangular exhaust nozzle over upper and lower surfaces, using the
Coandă effect
The Coandă effect ( or ) is the tendency of a jet (fluid), fluid jet to stay attached to a surface of any form. ''Merriam-Webster'' describes it as "the tendency of a jet of fluid emerging from an orifice to follow an adjacent flat or curved s ...
to establish control over
pitch.
["Demon UAV – Flying Without Flaps."](_blank)
''BAE Systems
BAE Systems plc is a British Multinational corporation, multinational Aerospace industry, aerospace, military technology, military and information security company, based in London. It is the largest manufacturer in Britain as of 2017. It is ...
'', Retrieved: 6 July 2019. For
roll control,
bleed air
Bleed air in aerospace engineering is compressed air taken from the compressor stage of a gas turbine, upstream of its fuel-burning sections. Automatic air supply and cabin pressure controller (ASCPC) valves bleed air from low or high stage engine ...
is blown over a Coanda surface installed on the
trailing edge
The trailing edge of an aerodynamic surface such as a wing is its rear edge, where the airflow separated by the leading edge meets.Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', page 521. Aviation Supplies & Academics, 1997. ...
of the wing. By controlling
boundary layer
In physics and fluid mechanics, a boundary layer is the thin layer of fluid in the immediate vicinity of a Boundary (thermodynamic), bounding surface formed by the fluid flowing along the surface. The fluid's interaction with the wall induces ...
conditions, the fluidic controls can also generate either greater
lift
Lift or LIFT may refer to:
Physical devices
* Elevator, or lift, a device used for raising and lowering people or goods
** Paternoster lift, a type of lift using a continuous chain of cars which do not stop
** Patient lift, or Hoyer lift, mobile ...
or
drag during the take-off and landing phases of flight.
Beyond the novel flight control system, the Demon was used to trial various other technologies, such as the manufacture and assembly of a fully bonded structure.
This structure possessed low cost material reinforcing features, which reportedly achieved roughly 50% cost savings over the use of conventional manufacturing processes. A key goal of the demonstrator was to trial cheaper, more
modular UAV technology, exploring designs have been generated through cross-disciplinary interactions.
See also
References
External links
BAE FLAVIIR projectEngineering and Physical Sciences Research Council (EPSRC) Casestudy
Ground video of the Demon's first flight
{{BAE aircraft
British Aerospace aircraft
2010s British experimental aircraft
Unmanned military aircraft of the United Kingdom
Tailless delta-wing aircraft
Single-engined jet aircraft
Two dimension thrust vectoring aircraft
Aircraft with fixed tricycle landing gear