Combined effect of circumferential roughness and squeeze velocity on ferrofluid squeeze film with rotating sphere and rough plate

Abstract

Based on the Jenkins model for ferrofluid flow regarding the performance of squeeze-film lubrication between rotating upper spherical surface and circumferentially rough lower plate is presented. Here, for hydrodynamic lubrication, we have adopted the ferrohydrodynamic theory. Further, using Christensen’s stochastic model, surface roughness is examined. In the paper, in the presence of a radially variable magnetic field, rotations of both the upper and lower surfaces as well as roughness of the surface, the Reynolds type equation for the squeeze-film bearing is established. By using the Reynolds type equation, expressions for the non-dimensional film pressure and load-carrying capacity are obtained for circumferential roughness pattern. Neuringer–Rosensweig (NR) model results are computed using the Jenkins model. The results show that non-dimensional film pressure increases remarkably when the non-dimensional radial parameter ( R) increases. Also, as the nominal minimum film thickness increases, load-carrying capacity decreases in the Jenkins model. However, as a result of Tables 5 and 6, the non-dimensional load-carrying capacity of the Jenkins model is improved compared to that of the NR model.