Conceptual design method adapted to electric/hybrid aircraft developments

Developing more electric, hybrid, and full electric aircraft became one of the most important research directions today. The available and emerging technologies, mainly due to the low specific energy of batteries, have not yet allowed the development of full electric aircraft with performance similar to existing conventional ones. This paper deals with the adaptation of conceptual design methodologies to electric/hybrid aircraft development. It introduces the analysis of energy fractions of flight mission stages into the conceptual design, the definition of extra constraints for optimisation, and the implementation of the hybridisation factor and power split. The applicability of the adapted method is demonstrated through the development case studies of a full electric small aircraft and a cargo hybrid UAV.