Design of a hybrid composite flywheel multi-rim rotor system using geometric scaling factors

The effects of geometric scaling on the static and dynamic behavior of a multi-rim hybrid press-fitted composite flywheel rotor are investigated and applied to its design procedure. It is verified that the stresses among the scaled multi-rim hybrid rotors remain the same as long as press-fit interferences are linearly scaled, curing temperature remains unchanged, and the rotational speed is inversely proportional. With the linearly scaled supporting stiffness of the scaled rotor and shaft, a relationship between inversely scaled critical speeds and rotational speeds remains unchanged. Double rim rotors of 5 kWh and 100 kWh energy storage are designed by scaling an optimized 0.5 kWh multi-rim rotor. Then, the rotors of 5 kWh were manufactured by wet-winding E-glass and T-700 fibers with a low-temperature cured epoxy system.