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Friction and Wear Research Volume 2, 2014
Effect of Slip Velocity on the Performance of a Magnetic Fluid Based Squeeze Film in Porous Rough Infinitely Long Parallel Plates SnehalShukla*1, Gunamani Deheri2 Department of Mathematics, ShriR.K.Parikh Arts and Science College; Petlad, Gujarat, India Department of Mathematics, Sardar Patel University; VallabhVidyanagar, Gujarat, India
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snehaldshukla@gmail.com; 2gm.deheri@rediffmaim.com
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Received 25 June 2013; Accepted 1 November 2013; Published 12 January 2014 Š 2014 Science and Engineering Publishing Company
Abstract An endeavor has been made to study and analyze the effect of slip velocity on the performance of a squeeze film in porous rough infinitely long parallel plates in the presence of a magnetic fluid lubricant. The Neuringer-Rosensweig model governs the fluid flow while the velocity slip is modeled by the method of Beavers and Joseph. A stochastic random variable with nonzero mean, variance, and skewness characterizes the random roughness of the bearing surfaces. With the adding of suitable boundary conditions, the associated stochastically averaged Reynolds’ equation is solved to obtain the fluid pressure, in turn, which results in the calculation of the load-carrying capacity. It is found that although the bearing suffers owing to transverse surface roughness, the performance of the bearing system can be improved to some extent by the positive effect of magnetization, considering the slip parameter at the minimum, at least in the case of negatively-skewed roughness. A comparison of this study with some established investigations indicates that the reduction of load-carrying capacity due to porosity and slip velocity is comparatively less here especially, when negative variance occurs.Of course, in augmenting the performance of the bearing system, the aspect ratio plays a central role even if the slip parameter is at the minimum. This article offers the suggestions that for a better performance of the bearing system, the slip velocity should be minimized, even if the magnetic strength has been chosen suitably. It is established that the bearing can support a load even in the absence of flow, unlike the case of a conventional lubricant. Keywords Parallel Plate Slider Bearing; Magnetic Fluid; Roughness; Slip Velocity; Porosity; Load Carrying Capacity
Introduction A slider bearing is the simplest and frequently
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encountered bearing system in the industries. The vast number of industrial slider bearing designs initially evolved from a desire to create a bearing having better load carrying capacity and/or to reduce friction and wear. Thus, great deal of emphasis was placed on the effectiveness of the bearing geometry to generate pressure and thus increasing load capacity. Several relevant studies on hydrodynamic lubrication of slider bearing have been published (Pinkus&Sternlicht, 1961; Cameron, 1972;Hamrock, 1994;Basu et al., 2009).In fact, the infinite long slider bearing is the idealization of a single sector shaped pad of a hydrodynamic thrust bearing. Such a bearing consists of a pivoted pad and a moving pad which may be plane, stepped, curved or composite shaped (such bearings are widely used in hydrodynamic generators and turbines). Self-lubricating porous bearings have been studied in the last few decades because of their industrial applications and machine manufacturing. These bearings have self-contained oil reservoir and hence continuous lubrication is not required.Numerous papers are available in the literature for the study of different types of porous bearings. (Wu, 1972) studied the squeeze film effects between two porous rectangular plates. Plane inclined porous slider bearing was analyzed by (Prakash&Vij, 1973) and it was concluded that the effect of porosity decreased the load carrying capacity and friction. (Patel & Gupta, 1983) extended the above analysis by considering the problem with slip velocity. All the above studies dealt with conventional lubricants. The use of the magnetic fluid as a lubricant in bearing system has attained considerable