Mission analysis and emissions for conventional and hybrid-electric commercial transport aircraft

A feasibility study of a hybrid-electric commercial transport aircraft was conducted by analyzing the simulated performance and lifecycle carbon dioxide (CO₂) emissions of a conventional single-aisle aircraft and an aircraft with a modified parallel hybrid-electric propulsion system. A flight performance simulation was developed in a MATLAB/ Simulink environment using publicly available aircraft data for the Boeing 737-700 commercial transport aircraft and the CFM56-7B26 turbofan engine. A parallel hybrid drivetrain was integrated into the aircraft performance model. Various missions with different degrees of hybridization and battery specific energy densities were simulated and compared to the conventional turbofan case. CO₂ emissions associated with fuel burn and electricity generation for charging battery systems were modeled for each hybrid aircraft configuration. The results indicated that reductions in CO₂ emissions per passenger mile were achievable using a parallel hybrid propulsion system as compared to conventional systems of equivalent range. A candidate propulsion system configuration was defined, which used a 50% electrical-power drivetrain and a battery specific energy density of 1000 W h∕kg. This configuration was estimated to produce 49.6% less lifecycle CO₂ emissions than a modern conventional aircraft, with a maximum range equivalent to that of the average of all global flights, making it a viable option for environmentally responsible aviation.