Tailored composites and digital optimization for efficient eVTOL propellers

Electrified urban air mobility (UAM) aircraft, including small drones and electric vertical takeoff and landing (eVTOL) vehicles, require highly efficient, lightweight propellers. These propellers must meet stringent mechanical performance requirements while being manufacturable at high volumes and low cost. This study explores a holistic optimization approach for eVTOL propellers using stitch-free, adhesive bonded T-NCFs and a semi-automated design tool “Proptimize”. The developed propeller design tool integrates mechanical performance, manufacturing quality, and economic considerations, enabling systematic optimization. Compared to a benchmark, the optimized propeller demonstrator achieved a weighted performance increase of approximately 45%. The key improvements include an over 80% increase in bending and torsional stiffness, a 30% reduction in manual labor and production time, slight gains in propeller thrust at minimal increase in overall weight. Additionally, lightweight performance—measured as longitudinal and torsional stiffness per kilogram—was enhanced by up to 94%.