Study on Active Damper with a Magnetic Fluid

Abstract

Study on control of vibration of a spring-mass system by using a magnetic fluid is conducted. The system consists of a cylinder filled with a magnetic fluid, a piston immersed in the magnetic fluid and a weight attached to the piston. The cylinder connected to the weight by a spring is excited to vibrate. The magnetic field necessary for stopping vibration of the mass is predicted. Validity of the prediction is proved by numerical experiments, where the equation of motion for the spring-mass system and the axisymmetric flow of the magnetic fluid are simultaneously solved. The magnetic field generated by a couple of coils can effectively damp the transient vibration and control the steady vibration to be extremely small.