System-level Trade Study of Hybrid Parallel Propulsion Architectures on Future Regional and Thin Haul Turboprop Aircraft

Abstract

This paper evaluates the potential benefits of applying hybrid parallel propulsion architectures to future turboprop aircraft that are expected to enter into service in 2030. Two baseline aircraft models are established by infusing viable 2030 airframe and engine technologies on state-of-the-art 19-passenger and 50-passenger aircraft models. Two parametric parallel hybrid architectures are proposed and applied on both size classes: Architecture 1 has two propellers, each driven by an engine and an electric motor in parallel, and allows in-flight recharging; Architecture 2 has four propellers, each driven by either an engine or an electric motor, and allows parallel operation during the cruise. A design space exploration is conducted on the powertrain design variables and the electric component key performance parameters. A constrained optimization implies that Architecture 1 and 2 can achieve fuel savings of about 2.6% and 6.6%, respectively, given 2030 electric component technology assumptions. Electric taxi consistently results in fuel saving when battery technology is beyond the projected 2030 level. Preliminary sensitivity studies show that the performance of Architecture 2 is more sensitive to the battery technology compared to Architecture 1 due to its extensive use of battery energy during the cruise.

Systems Integration Framework for Hybrid-Electric Commuter and Regional Aircraft

“…Cinar et al [34,35] introduce a multidisciplinary aircraft sizing and synthesis framework called Electrified Propulsion Architecture Sizing and Synthesis (E-PASS), which is applied for the design space exploration of hybrid-electric commuter aircraft carrying 19-50 passengers [36]. Cai et al [37] further investigate additional parallel-hybrid architectures using the same framework. Both studies use NASA FLOPS to make component-based weight estimates, including those of the subsystems.…”