Configuration of Hybrid Fuel-Electric Airplane Model Based on Full Flight Path Performance

Abstract

The feasibility of enhancing the efficiency of hybrid fuel-electric airplane is investigated. The airplane model considered in this work is a hybrid version of Aerosonde propelled by an integrated system of internal combustion engine (ICE) and electric motor (EM). Modified versions of Breguet equation are used to calculate the contribution of the ICE propulsion to the range and endurance of the airplane. On the other hand, the range and endurance components due to EM propulsion are calculated using Payne range strategy based on battery capacity. In order to find the most feasible propulsion configuration; multiple configurations are compared; including conventional all-fuel, full-electric, parallel-hybrid and fuel-first strategy (FFS), which is based on parallel-hybrid design, where fuel is burned during the early phases of the flight then the flight is completed in the fully-electric mode. The preceding propulsion types are investigated for all flight phases including takeoff, climb, cruise, descent, and landing. Impact on airplane weight due to additional equipment is considered. It is found that by adopting the FFS, range can be extended by 7% and endurance by 6% above the parallel-hybrid case. In terms of fuel consumption, implementing FFS yields a fuel saving of 6% relative to parallel hybrid.