Being able to fly and control aircraft without conventional control surfaces will bring benefits to both military and civil aircraft. In military jets the stealth characteristics will be enhanced by a reduction in edges and gaps that can increase radar cross section. Additionally, the number of moving and electrical parts in both military and civil aircraft will be reduced which has clear implications for cost, reliability, weight, efficiency and maintenance.
Flapless flight
Flapless aircraft use fluidic thrust vectoring and circulation control, which controls pitch and roll by using a secondary air flow. Control is achieved by blowing air from the trailing edge of the wing which entrains the upper surface flow and so increases lift. Eliminating moving control surfaces can result in increased reliability in autonomous flying vehicles.
The engines are embedded in an airframe that has curved surfaces on either side of the primary and secondary jet exhausts. The revectored thrust along the curved surface generates forces for pitch control.
Research
The technical research has been split into 7 themed areas:
- Aerodynamics
- Control systems
- Electromagnetics
- Manufacturing
- Materials and Structures
- Numerical simulation
- Integration
Over the past year, the Leicester team has developed a software package for the flight path planning task. The package incorporates several planning methods and is able to run in real-time and deal with uncertain situations.
Algorithms for co-ordinated mission task planning involving several UAVs are currently under development. Some initial robust control systems have been designed for the demonstrator model and control schemes, which explore FTV (fluidic thrust vectoring) and CC (circulation control which replaces conventional flaps by blowing air from the trailing edge of the wing) actuators will be a major development. A health management/condition monitoring system is also planned.
In addition, the Leicester team will explore the potential of multiple sensors (sensor arrays) distributed across an airframe to provide virtual air data for use in the health monitoring and improved control of future UAVs.
Another key project will be developing fault detection mechanisms for use in a fault tolerant flight control system, which can automatically adapt for failures sustained during a mission thereby maintaining adequate flight performance and stability.
The flapless air vehicle project is being managed from Cranfield University and includes nine other university partners: The University of Leicester, The University of Liverpool, The University of Manchester, The University of Nottingham, The University of Southampton, The University of Wales (Swansea), Warwick University, Warwick Manufacturing Group, The University of York and Imperial College of Science, Technology and Medicine.
The ultimate aim of the programme is to then deliver a flying demonstrator vehicle which makes use of all the technologies being researched for a maintenance free, low cost UAV without conventional control surfaces and without performance penalty over conventional craft. This is scheduled for completion in early 2009.
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This page was last updated on: 2006-05-23
