News | Friday, 23rd October 2015

The future of flight: plasma aircraft wings

Electrically charged field replaces mechanical flap

A prototype plasma wing with the distinctive purple electrical field

ELECTRICALLY charged plasma fields are being used to improve aircraft performance by generating lift in place of mechanical wing flaps and slats.

Tests show that plasma could be adopted to replace the actuator flaps on aeroplanes that help them to climb, descend and alter speed.

Wings generate lift as air moves over the top of the surface of the aerofoil, creating a vacuum that pulls the aeroplane up. A fully operated plasma system would create cheaper, lighter and greener aeroplanes by replacing the flaps and slats’ role on a wing.

When the plasma is switched on, an electrical current passes through electrodes to generate an ionised field along the wing, known as the single dielectric barrier discharge (SDBD) plasma actuator, without any moving parts.

Taking flight

Research by scientists at Manchester Metropolitan University and The University of Glasgow has refined the system so air velocity is greater with an ionised field than the comparable hydraulic system. This, in turn, allows for lower take-off and landing speeds, shorter runways, improved manoeuvrability and lower fuel consumption.

Lead researcher Dr Rasool Erfani, from Manchester Met’s School of Engineering, said: “The fourth state of matter, plasma, can improve aircraft performance. For aerodynamic applications, they can be used as flow control devices to delay separation and augment lift on a wing. Our novel actuator design, namely MEE-DBD plasma actuator, can induce velocities greater than the baseline case consuming lower power.

“So, in today's economic and environmental climate, coupled with the human desire to travel, the benefit of such flow control technique is not only the costs but the ability to directly compete with the rugged and thoroughly proven technology of the conventional aircraft flow control devices such as flaps and slats.”

A typical SDBD Plasma Actuator system consists of two electrodes separated by a dielectric layer, typically Kapton, glass, quartz or ceramics. When activated, a purplish glow is emitted and spreads out across the dielectric surface. It is lightweight, easy to repair and able to follow the curvature of surfaces such as an aircraft wing.

Velocity

The aim of many studies has been to increase the induced momentum of plasma actuators to compete with traditional pneumatic systems.

Tests were conducted on unmanned aerial vehicles (UAV) and prototype wings in wind tunnels. The findings built on previous research and established a better performing plasma ignition time and greater air velocity.

The research is published in the journal Acta Astronautica, funded by the EPSRC, and presented in the American Institute of Aeronautics and Astronautics, AIAA.