Critical impact of thermal management systems on on-board systems in hydrogen-powered aircraft

<title>Abstract</title> Hydrogen-powered aircraft offer a promising pathway to reduce the aviation sector's climate impact, with fuel cells providing high-efficiency power conversion at around 50%. However, producing considerable waste heat at around 80°C. Since this heat is generated inside the aircraft, implementing an active thermal management system to dissipate it becomes a critical design consideration. In this paper, a holistic design methodology for the TMS to calculate its mass, power demand, and drag is presented. Exceeding previous work, the assessment includes the impact of this integration on the design of other on-board systems and the aircraft's performance in terms of mission energy. Applied to the 70-passenger ESBEF-CP1 concept aircraft, the analysis shows that the TMS adds around 5200kg system mass distributed over ten pods, 9kN drag, and 2MW peak fan power, resulting in a 32% increase in mission energy demand after only a single iteration of the other systems design. The findings highlight that relying solely on ambient air as a heat sink results in high drag and fan power demand, challenging aircraft feasibility.