Influence of orifice distribution on the characteristics of elastic ring-squeeze film dampers for flywheel energy-storage system

This paper investigates the influence of orifice distribution on the damping characteristics of elastic ring-squeeze film dampers (ERSFDs) for a flywheel energy-storage system. Finite-element method is employed to calculate the oil-film force of the ERSFD with different orifice distribution. The relationship of the oil-film force versus the orifice location in both axial and circumferential direction is explored. The principle for the optimum orifice location is summarized and verified via varying the orifice radius. Moreover, the effects of an ERSFD on the vibration abatement and its influence on the electromagnetic behavior of the motor/generator are presented. It is shown that orifices with the optimum distribution can play the greatest role in adjusting the damping coefficient, providing guidelines for the design, and application of ERSFD. Although the impact of ERSFD on torque, voltage, and the motor efficiency is marginal, the presence of ERSFD can dramatically suppress the radial electromagnetic force and the resonance amplitude of the flywheel energy-storage system rotor system.