Hybrid Cooling System for Thermal Management in Electric Aerial Vehicles

Continuous improvements and innovations towards sustainability in the aviation industry has brought interest in electrified aviation. Electric aircrafts have short missions in which the temporal variability of thermal loads is high. Lithium-ion (Li-ion) batteries have emerged as prominent power source candidate for electric aircrafts and Urban Air Mobility (UAM). UAMs and Electric aircrafts have large battery packs with battery capacity ranging in hundreds or thousands of kWh. If the battery is exposed to temperatures outside the optimum range, the life and the performance of the battery reduces drastically. Hence, it is crucial to have a Thermal Management System (TMS) which would reduce the heat load on battery in addition to the cabin thermal loads.

Thermal management can be done through active or passive cooling. Adding a passive cooling system like Phase Change Material (PCM) to the TMS reduces the design maximum thermal loads. However, the added weight of the PCM module may at times outweigh the benefit of energy savings. This research studies thermal management of electric aircrafts/UAMs using Vapor Cycle System (VCS), Phase Change Material (PCM) and combination thereof (Hybrid). The three TMS architectures are compared for different UAM/electric air vehicle, and the results will help us conclude the best method of cooling. The analysis of the results quantifies the impact of the architecture on the weight and size metrics on the UAM/electric air vehicles. Also, three representative UAM/electric air vehicles of different capacities are simulated using MATLAB, and their results will help us to optimize the best TMS that can be applied to electric aerial vehicles of varying passenger capacity depending on its heat loads. The simulated results show for lower heat loads PCM alone, and for higher heat loads hybrid TMS provide best cooling solution.