Multidisciplinary Exploration of DRAGON: an ONERA Hybrid Electric Distributed Propulsion Concept

For civil transport aircraft, decreasing the Fan Pressure Ratio has been a solution to improve fuel efficiency. There is however a limit associated to this approach because of the resulting size of the fan. One solution to the problem is Hybrid Electric Distributed Propulsion as electric motors do not loose efficiency when scaled down and the large number of fans allows to maintain a low Fan Pressure Ratio without geometry issues. Within the European Programme Clean Sky 2, ONERA decided to explore the possible implementation of Hybrid Electric Distributed Propulsion on a transport aircraft carrying 150 passengers at a cruise Mach number of 0.78 over a range of 1200 NM to match airlines flexibility requirements. To perform conceptual design studies, a research baseline concept called DRAGON (Distributed fans Research Aircraft with electric Generators by ONERA) has been defined. Characterized by distributed fans located all along the wing span on the pressure side in a rearward position, this configuration has been investigated by disciplinary experts. Concurrently, fuel consumption benefits have been computed for various technology options.