Behaviour of hydromagnetic squeeze films between two conducting rough porous circular plates

Abstract

In this paper, the problem of squeeze films between electrically conducting rough porous surfaces and electrically conducting lubricant in the presence of transverse magnetic field is investigated for circular shape of the bearing surfaces. The bearing surfaces are assumed to be transversely rough. The roughness of the bearing surface is modelled by a stochastic random variable with non-zero mean, variance, and skewness. The associated Reynolds equation is stochastically averaged with respect to the random roughness parameter. Then, it is solved with appropriate boundary conditions to get the pressure distribution, which is further used to obtain the load carrying capacity leading to the calculation of response time. The results are presented graphically. It is noticed that the bearing suffers on account of transverse surface roughness in general. However, the situation can be retrieved up to a certain extent in the case of negatively skewed roughness especially, when negative variance occurs by suitable choice of plate conductivities. In addition, it is observed that the bearing with magnetic field can support a load even when there is no flow. field to create a body force which pumps the fluid between the bearing surfaces. Since the liquid metals are good electrical conductors, it is possible to increase the load carrying capacity by utilizing the electromagnetic force thereby, overcoming the defect associated with lubricants at high temperature and hence alleviating the drawback of low viscosity. Considerably high increase in load carrying capacity is possible with the use of super conducting magnets while very little power is required to provide the magnetic field.A number of theoretical and experimental studies on the hydromagnetic lubrications for porous as well as plane metal bearings have appeared. Elco and Huges [1] studied magnetohydrodynamic pressurization in liquid metal lubrication. Kuzma [2] and Kuzma et al. [3] analysed the behaviour of magnetohydrodynamic squeeze films. Shukla [4] investigated the hydromagnetic theory of squeeze films for conducting lubricants between two non-conducting JET390

Theoretical study of Shliomis model based magnetic squeeze film in rough curved annular plates with assorted porous structures

“…It is easily observed that the dimensionless pressure distribution in the bearing system given by equation (18) and equation (21) while the non dimensional load carrying capacity of the bearing system is obtained from equation (20) and equation (22). It is clearly seen that the pressure increases by…”

“…[19] analyzed the effect of magneto-hydrodynamic squeeze film characteristics between curved annular plates. On the basis of the Christenson and Tonder's stochastic model of roughness, the discussion carried out by [20][21][22][23] reported that the negatively skewed roughness turns in better performance. All these above studies established that increasing values of porosity caused reduced load carrying capacity and friction.…”

A Study of Hydromagnetic Longitudinal Rough Circular Step Bearing

“…The representation for dimensionless pressure profile is given in (11) while the nondimensional load bearing capacity is governed by (12). From these equations it is clearly observed that the load carrying capacity…”

“…The hydromagnetic squeeze films between two conducting rough circular plates are studied by Vadher et al [12]. It was investigated that the negative effect of roughness got minimized up to some extent by applying magnetization.…”

Ferrofluid Based Squeeze Film Lubrication between Rough Stepped Plates with Couple Stress Effect

“…It was noticed that the squeeze film characteristics got enhanced for transverse roughness whereas the bearing suffered owing to the existence of longitudinal roughness pattern. Vadher et al (2008) considered the problem of squeeze films between electrically conducting rough porous surfaces and electrically conducting lubricant in the presence of a transverse roughness for a circular shape of the bearing surfaces. The negative influence of transverse surfaces roughness was reduced due to magnetization.…”