Analysis of Potential Thermal Management Systems for Electric Short-Range Aircraft in the Cluster of Excellence SE²A

Electric aircraft powered by fuel cells and batteries represent a promising avenue for reducing emissions from the aviation industry and meeting the ambitious climate goals. However, the increasing waste heat of the powertrain components and their low permitted operating temperatures place significant demands on the thermal management system. This study delineates the methodological approach employed in the Custer of Excellence "Sustainable and Energy-Efficient Aviation" (SE²A) to design and simulate a thermal management system for electric aircraft. The workflow is divided into four fundamental steps: a thermal analysis to identify heat sources and sinks, a generation of potential system configurations, design of the thermal components for a specific design point, and performance evaluation of the system in an off-design analysis. The thermal requirements are primarily determined by the fuel cell, which accounts for a proportion of 80 to 95 % of the total waste heat, while the liquid hydrogen fuel tank can only reduce the total amount of heat by 5 % when considered as a heat sink. The remaining waste heat must be dissipated by a heat exchanger to the environmental air. The optimization of these heat exchangers is conducted using a genetic algorithm, with the constraints imposed by the available installation space and aircraft-related boundary conditions. The optimization process yields a Pareto front comprising potential designs with varying drag and weight characteristics. Exemplary designs are investigated in detail over the course of a flight mission, revealing the potential for drag reduction during cruise with the implementation of an appropriate control strategy.