Mechanical energy is stored in an experimental car by means of a flywheel. The flywheel is shaped like a relatively thin disk of 0.6 m diameter and rotates at 18,000 rpm. The composite mate rial of...

Mechanical energy is stored in an experimental car by means of a flywheel. The flywheel is shaped like a relatively thin disk of 0.6 m diameter and rotates at 18,000 rpm. The composite mate rial of which the flywheel is constructed has an effective thermal conductivity so small that the flywheel is essentially insulated. Estimate the maximum temperature on the flywheel surface when spinning in 20°C air. Assume that the boundary layer flow is turbulent.