A new type controllable squeeze film damper using an electromagnet

The paper presents stability of a rotor system with a squeeze film damper (SFD) using an electromagnet. The electromagnet is installed in the inner damper of the SFD. The proposed SFD has basically the property of a conventional SFD and variable damping according to the strength of the applied electric current. Therefore, when the applied current is controlled, the whirling amplitude of the rotor system can be effectively reduced in a wide operational speed range. In the present work, the performance of the SFD was experimentally investigated according to the magnetic field strength. When the applied current increased, the whirling amplitude greatly reduced at the critical speeds and damping ratio increased. 0 2004 American Institute of Physics.