Introducing large-scale multiphysics topology optimization for electric aircraft battery pack design

Electric Vertical Take-Off and Landing (eVTOL) vehicles hold great promise for mitigating traffic congestion and the performance of eVTOL battery packs plays a crucial role in advancing this mode of transportation. This paper introduces a methodology for optimizing eVTOL battery packs, employing level-set topology optimization while accounting for multiphysics loads to achieve a lightweight structure that is thermally and structurally efficient. A beam model at the system level simulates the boom hosting the battery pack, determining the mechanical load borne by the battery pack and an electrochemical model predicts the batteries’ maximum heat generation given a mission profile. These contributions serve as inputs for the thermo-mechanical battery pack model. The workflow is exemplified with a battery module comprising seven battery cells with the objective of minimizing thermal and structural compliances while exploring the trade-off between these two factors. Subsequently, the model is expanded to optimize the entire boom structure. The model, with over 50 million degrees of freedom, is solved using distributed memory parallelism to minimize structural compliance while adhering to volume, stress, and temperature constraints. This study demonstrates the application of large-scale multiphysics optimization in designing battery packs, facilitating the development of lightweight electric aircraft.