Effect of surface roughness on static and dynamic characteristics of MHD couple stress lubrication of parabolic slider bearing

The effect of surface roughness on static and dynamic characteristics of parabolic slider bearing lubricated with couple stress fluid in the presence of magnetic field is theoretically analysed in this paper. The modified stochastic MHD couple stress Reynolds-type equation is derived on the basis of Christensen stochastic theory and considered two types of roughness pattern namely longitudinal and transverse. Expressions for steady pressure and load, dynamic stiffness and damping coefficients are obtained for both roughness patterns. Compared to smooth surface, transverse roughness pattern provides larger load-carrying capacity, dynamic stiffness and damping coefficients, whereas longitudinal roughness pattern has adverse effects. The presence of couple stress and applied magnetic field improves the bearing performance.