Rolls Royce and EADS have announced a joint project to develop a commercial aircraft which works on a similar principle to today's hybrid cars. The E-Thrust electric aeroplane will rely heavily on advanced materials technology, including many predicted future innovations. It is estimated that the project will complete in 2050.
.jpg)
The E-Thrust is an electrical distributed propulsion system concept for lower fuel consumption, fewer emissions and less noise. Image credit: Airbus - EIVI
The E-Thrust concept developed by EADS uses a "distributed propulsion system" of six electrically powered fans to propel the aircraft. These fans will be powered by a single electricity-generating turbine engine running on gas.
According to the team, splitting up the propulsion system in this way will allow each component to be developed and optimized independently, making for a more efficient process.
Each of the components in the propulsion system - the propulsion fans, the energy storage, and the central gas power unit - will rely on enabling materials technology which is not currently feasible. This is one of the reasons for the long-term nature of the project - by the time the concept has matured to a prototype stage, the development team predict that technology will have advanced enough to make their ideas viable.
Lightweight composite fan blades
The E-Thrust will rely on arrays of lightweight, high-efficiency electrical fans to propel the aircraft forward. In current designs, there are six fans grouped in two arrays of three - however, the optimum number arrangment of fans is still to be determined.
The fan blades will be made of a lightweight advanced composite to keep the weight of the units down to an absolute minimum. This will allow them to be placed in the best positions for the aerodynamics of the aircraft - this is a huge improvement over modern turbofan jet engines, which have to be hung under the wings due to their size and weight.
"Totally superconducting electrical machine"
The electric motors powering the fans - and all connections between the fans, energy storage, and gas power unit - will use superconducting materials. This is a bold step, as it requires cryogenic cooling throughout all the electrical systems.
If a viable system can be designed, however, there are huge benefits to be gained in power and efficiency. Superconducting materials, such as the proposed magnesium diboride, which is currently used in MRI machines, have zero electrical resistance.
In all electrical systems, a significant amount of power is lost as heat due to resistance in the electrical conductors, and using superconductors throughout the system would eliminate this loss. Superconducting electromagnets, as in MRI machines, are also capable of generating huge magnetic fields - laboratory tests have demonstrated fields of up to 17 Tesla, which would make for an incredibly powerful electric motor.
A superconducting motor would also lead to more weight savings, as the ceramic coils and pucks would be far lighter than traditional copper and iron structures used in conventional electric motors.
A paradigm shift for air travel?
Whilst modern aircraft from companies like Airbus are huge technological achievements, they have thus far been optimizations of a mature technology. This project is an exciting step away from the ubiquitous turbofan - it looks set to provide a plethora of commercialization opportunities for advanced materials, and eventually make huge reductions in the environmental impact of our every-increasing air travel.