Optimization of flywheel rotor made of three-dimensional composites

Annular disks made of three-dimensionally carbon-fiber-reinforced composites were optimized using numerical calculations, targeting high rotation speed and high energy density in a rotor system. This study examined two disk reinforcement patterns. One had added radial bundles at locations requiring high strength. The other had no added radial bundles. Two disk thicknesses were examined: uniform thickness and varied thickness, becoming thinner with distance from the disk center. Disk failure rotation speeds were estimated using the maximum stress criterion. The maximum burst tip speed was calculated as 1376 m/s for the uniform thickness no-bundles-added model and 1797 m/s for the varied thickness no-bundles-added model. Maximum energy densities including the aluminum alloy hub were calculated, respectively, as 124 and 151 Wh/kg.