New power concept at show
Rolls-Royce and EADS are showing a new power concept for advanced future airliners at the Paris Air Show this week. It could help reduce CO2 emissions, make less noise and dramatically reduce fuel burn by the middle of the century.
Such an airliner would be powered by a serial hybrid propulsion system, which is similar in concept to the technology found in a growing number of energy efficient motor cars. Propulsion is provided by six electrically-driven fans distributed along the wing span in clusters of three.
A single, large advanced gas turbine generates electrical power which is stored in an advanced energy storage system that could be based on Lithium-air energy storage technology. While an aircraft climbs, the distributed fans draw power from the energy storage system. But while descending they act like wind turbines to generate electrical energy which re-charges the batteries.
For the megawatt levels of power that an electrical distributed propulsion network requires, a new high-power superconducting electrical system will have to be designed and validated based on cryogenic cooling at temperatures as low as -252ºC.
A major benefit of the distributed propulsion system is that it can be integrated into the airframe’s structure to maximise aerodynamic efficiency and optimise the airflow around it. This reduces the aircraft’s weight, drag and the amount of noise it makes.
Ric Parker, Director for Research and Technology at Rolls-Royce, said: "The conceptual airliner with the E-Thrust distributed propulsion architecture demonstrates the sort of futuristic thinking backed by solid research and emerging technologies that will lead to a real step-change in airliner design. This in turn would result in a significant reduction in the environmental impact of aviation."
A model of the E-Thrust concept aircraft and its innovative power system can be seen at the Paris Air Show. The E-Thrust concept is part of the on-going Distributed Electrical Aerospace Propulsion (DEAP) project which is co-funded by the UK’s Technology Strategy Board and, in addition to Rolls-Royce and EADS Innovation Works, involves the Universities of Cranfield and Cambridge.