Lubrication performance of finite journal bearings considering effects of couple stresses and surface roughness

MHD couple stress nanofluid flow in a permeable wall channel with entropy generation and nonlinear radiative heat

“…To the best of authors' knowledge, the combined effects of buoyancy forces, suction/injection, magnetic field, viscous and Joule heating on entropy production in a conducting non-Newtonian couple stress nanofluid has not been reported in the literature yet. Meanwhile, the hydromagnetic mixed convective flow of couple stress nanofluid with heat transfer over a permeable surface in the presence of radiative heat absorption appears to be increasingly important due to its wide applications in the field of micro-electro-mechanical-systems (MEMS), such as micro MHD pumps, micro-electronic devices, rapid mixing of fluids in biological processes, biological transportation, drug delivery and heat exchanger, Dulal et al (1988), Chiang et al (2004), Leong et al (2012). Surface permeability plays a very vital role in micro-mixing of biological fluid, it enhances transpiration process to take place at the boundaries in a micro system, whereby suction is exerted in order to remove reactants while injection is applied to add reactants in the process.…”

Combined Effect of Slip Velocity and Roughness on the Jenkins Model Based Ferrofluid Lubrication of a Curved Rough Annular Squeeze Film

“…Several methods have been proposed to deal with the effect of surface roughness on the performance characteristics of squeeze film bearings, Christensen and Tonder (1970), Christensen and Tonder (1969a) and Christensen and Tonder (1969b) developed the stochastic theory of Tzeng and Saibel (1967) to study the effect of surface roughness in general. A good number of research papers are abound dealing with the hydrodynamic lubrication of rough surfaces using stochastic approaches of Christensen and Tonder (1970), Christensen and Tonder (1969a) and Christensen and Tonder (1969b) such as the works on the porous annular disks by Ting (1975), the journal bearing by Guha (1993), Chiang et al (2004), the spherical bearing by Gupta and Deheri (1996), Hydrodynamic slider bearing by Naduvinamani et al (2003), the curved annular plates by Bujurke et al (2007), Deheri et al (2011) and Shimpi and Deheri (2012), the circular plates by Patel et al (2009), Shimpi and Deheri (2010). All the above studies make it clear that roughness affects the performance significantly.…”

Jenkins model based magnetic squeeze film in curved rough circular plates considering slip velocity: A comparison of shapes

“…[34][35][36] modified the stochastic model of [37] to study the effect of surface roughness in general. A number of investigations adopted the stochastic model of [34][35][36] to study the effect of surface roughness [38][39][40][41][42][43][44][45][46][47][48][49]. [50] studied the effects of various porous structures on the performance of a Shliomis model based ferrofluid lubrication of a squeeze film in rotating rough porous curved circular plates.…”