Some porous squeeze film-bearings using ferrofluid lubricant: A review with contributions

Abstract

Based on ferrofluid flow model given by R.E. Rosensweig, a general equation for different slider squeeze film-bearing design systems, formed by solid upper surface and lower porous plate, is theoretically derived considering the effects of porosity, permeability, squeeze velocity, tangential velocity and oblique variable magnetic field. While deriving the general equation, continuity equation and Darcy’s law are also considered. Expressions for pressure and load-carrying capacity for different squeeze film-bearing design systems are obtained. The results for dimensionless load-carrying capacity are computed and compared with previous results in some cases. The results indicate the better performance of different bearing systems when ferrofluid is used as lubricant. Further, some important conclusions are also made. Two permeability models – globular sphere and capillary fissures are discussed. The variable magnetic field is considered because uniform magnetic field does not enhance bearing performances.