The modern rotating machinery has a tendency of high operating speed, high load capacity and light weight. Thus it is becoming increasingly important that a rotating machine can have a capability of changing its dynamic characteristics so that the excessive vibrations, occurring particularly when passing through critical speeds or unstable speed regions, can be avoided.
In this work, a squeeze film damper (SFD) using magneto-rheological fluid (MRF), which is known to behave as a Bingham fluid, is tested to check the ability of changing its dynamic properties such as damping and stiffness. It requires to solve the Reynolds equation for Bingham fluid and then to calculate the pressure distribution of MR SFD. Magnetic circuit analysis is also performed to avoid the magnetic saturation of MR SFD and to determine the feasible design parameters. Numerical simulations are extensively carried out to investigate the effects of design parameters, sealing and applied magnetic field on the dynamic properties of MR SFD. Finally, the simulation results are compared with experimental ones. It is found that the proposed MR SFD has the capability of changing its dynamic characteristics, following the general trend of the simulation results, but the analysis model needs further improvements for accurate prediction of experimental results.
