Offset Strip-Fin vs. Novel Impingement Heat Exchangers for Megawatt SOFCs Powering Electric Aircraft Propulsion

Abstract

Solid oxide fuel cells (SOFCs) offer high efficiency and high-temperature capability, making them promising for combined heat and power generation in zero-emission aviation. Their use in hydrogen-powered electric propulsion, however, is constrained by low gravimetric power density and stringent thermal management requirements. This study addresses these challenges by comparing two heat exchanger (HEX) concepts—offset-strip plate-fin (OSF) and novel jet-impingement (iHEX)—for cathode air preheating in a megawatt-class SOFC system. The analysis employs well-established heat transfer and pressure drop correlations combined with multi-objective optimization to explore feasible design points and quantify performance trade-offs for a 2-MW heat load representative of take off conditions. Results show that the iHEX achieves higher gravimetric power density at comparable pumping-power penalties, while the OSF provides superior volumetric power density, favoring compact integration. The findings highlight key thermal, hydraulic and aerodynamic trade-offs relevant to future SOFC-powered regional aircraft.