System-level utilization of low-grade, mw-scale thermal loads for electric aircraft

This paper describes the analysis of a hydrogen fuel-cell-powered transport-category aircraft, similar in mission performance to a Boeing 737-800. The configuration examined produced peak waste heat loads up to 16 megawatts. Contemporary thermal dissipation systems, such as radiators, lead to a substantial drag contribution due to the large cooling surfaces required. In the paper, we 1) characterize the magnitude, occurrence, and effect of the thermal management challenge for fuel-cell-powered civil air transport, as exemplified through the CHEETA aircraft; 2) investigate multiple thermal management strategies that leverage thermal energy deposition from waste heat sources as a contribution within the propulsion system; and 3) demonstrate the impact of applying one of those strategies to enhance aircraft performance. We show that thermal system design for MW-scale electric aircraft cannot be considered as a simple drag penalty to be quantified after preliminary design is complete: power, propulsion, and thermal systems must be designed together.