Hybrid planes trying to charge into action (BBC)
Jon Stewart
How would you feel about flying on an electric airliner? Current planes may be noisy, rattly, and relatively inefficient, but there’s something reassuring about being able to hear the constant roar of the engines, or glance out of the window and see them.
So the airliner of the future may feel very alien to anyone comfortable with our current mode of flying – at least if an ambitious model called the eConcept is anything to go by. Designed by European aviation powerhouse, EADS (which announced it will be renamed Airbus Group next year), together with Rolls Royce, the eConcept shows how cutting-edge technology and materials could combine to make more efficient and quiet aircraft that take their cues from the hybrid-car model.
“We imagine the impossible, and then try to think how possible it might be,” Professor Ric Parker, Chief Technical Officer of Rolls Royce tells me. “We don’t just do science fiction. We want things that are maybe a stretch for today’s technology, but where the basic laws of physics aren’t being broken. That’s the bounds we are setting ourselves.”
Ambitious claims require ambitious ideas, and Rolls Royce is proposing something completely different to a traditional propeller driven by an electric motor – like other efforts being tested. Its system, known as E–Thrust, is what Rolls Royce calls a distributed electrical power system. Instead of several engines slung under the wings, E–Thrust will use a single turbine engine towards the back of the aircraft. “The turbine is connected to a generator, and it does not provide any thrust to propel the aeroplane,” insists Dr Jean Botti, EADS Chief Technical Officer. “It is just there to drive the generator.”
The rearward positioning means that the engine’s air intake can help reduce drag by sucking in and therefore reducing what is known as the boundary layer – an area of air flow next to the surface of the plane that causes the most resistance. Less drag means greater efficiency.
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more: http://www.bbc.com/future/story/20130802-powering-up-hybrid-planes