Ferrofluid Lubricated Porous Squeeze-Film Bearing with the Modified Condition of Pressure Continuity at the Film-Porous Interface

Abstract

Modified Reynolds-Darcy equation for ferrofluid lubricated squeeze-film bearing, made by flat circular porous upper and flat circular impermeable lower discs, is derived. The ferrofluid is controlled by oblique variable magnetic field (VMF) and VMF is important because of its advantage of generating maximum field at the required active contact zone. The porous matrix is considered because of its advantageous property of self-lubrication. Moreover, the validity of the Darcy's law is assumed in the porous matrix. Expression for dimensionless film pressure p in terms of Bessel function by considering the effect of existence of pressure difference at the film-porous interface is obtained. The expression for dimensionless load-carrying capacity W is also obtained. The effects of dimensionless radial parameter, inverse of the dimensionless film thickness parameter (h 0 / h) , magnetization parameter and squeeze velocity are studied on p, whereas the effects of the inverse of the dimensionless film thickness parameter and magnetization parameter and squeeze velocity are studied on W. Moreover, the effect of dimensionless pressure difference P at the film-porous interface is studied on W n (which is the term because of existence of the pressure difference at the film-porous interface). The results show that p increases for smaller values of radial parameter, larger values of magnetization parameter and when (h 0 / h) ≤ 12, whereas W increases for larger values of magnetization parameter and when (h 0 / h) ≤ 12. The squeeze velocity have no effects on the variation of p and W. Moreover, the results for W n show that it increases with the increase of P.