Evaluation of the performance characteristics of double-layered porous micropolar fluid lubricated journal bearing

Abstract In this article a mathematical model of single layered nano-fluid lubricated PJB (porous journal bearing) has been formulated. The nano-lubricant's impact on the efficiency of said journal bearing has been studied using modified Darcy's law and boundary conditions. The different nanoparticles often used as an additive in industrial lubricating oils improve their viscosity significantly. The brief description of dimensionless performance characteristics of the investigated bearing was obtained by the use of the nano-lubricant's modified Krieger-Dougherty viscosity model. The observations revealed that the output characteristics are substantially improved by using nano-lubricant. The present study was validated by comparing the findings of recently published data with micropolar fluid and was found to be completely compatible since data with nano-lubricant are still unavailable.

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Theoretical analysis of single-layered porous short journal bearing under the lubrication of micropolar fluid

Journal of the Brazilian Society of Mechanical Sciences and Engineering ◽

10.1007/s40430-019-1861-1 ◽

2019 ◽

Vol 41 (9) ◽

Cited By ~ 3

Author(s):

Biplab Bhattacharjee ◽

Prasun Chakraborti ◽

Kishan Choudhuri

Keyword(s):

Theoretical Analysis ◽

Micropolar Fluid ◽

Journal Bearing

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Non-linear stability analysis of micropolar fluid lubricated journal bearings with turbulent effect

Industrial Lubrication and Tribology ◽

10.1108/ilt-07-2017-0212 ◽

2019 ◽

Vol 71 (1) ◽

pp. 31-39

Author(s):

Subrata Das ◽

Sisir Kumar Guha

Keyword(s):

Stability Analysis ◽

Linear Stability ◽

Micropolar Fluid ◽

Journal Bearing ◽

Journal Bearings ◽

Turbulent Regime ◽

Content Type ◽

Non Linear ◽

The Stability ◽

Bearing System

Purpose The purpose of this paper is to investigate the effect of turbulence on the stability characteristics of finite hydrodynamic journal bearing lubricated with micropolar fluid. Design/methodology/approach The non-dimensional transient Reynolds equation has been solved to obtain the non-dimensional pressure field which in turn used to obtain the load carrying capacity of the bearing. The second-order equations of motion applicable for journal bearing system have been solved using fourth-order Runge–Kutta method to obtain the stability characteristics. Findings It has been observed that turbulence has adverse effect on stability and the whirl ratio at laminar flow condition has the lowest value. Practical implications The paper provides the stability characteristics of the finite journal bearing lubricated with micropolar fluid operating in turbulent regime which is very common in practical applications. Originality/value Non-linear stability analysis of micropolar fluid lubricated journal bearing operating in turbulent regime has not been reported in literatures so far. This paper is an effort to address the problem of non-linear stability of journal bearings under micropolar lubrication with turbulent effect. The results obtained provide useful information for designing the journal bearing system for high speed applications.

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Simulation studies on static thermal behaviour of true elliptical and orthogonally displaced non-circular journal bearing

Industrial Lubrication and Tribology ◽

10.1108/ilt-06-2015-0075 ◽

2016 ◽

Vol 68 (3) ◽

pp. 349-360 ◽

Cited By ~ 6

Author(s):

Amit Singla ◽

Amit Chauhan

Keyword(s):

Journal Bearing ◽

Load Capacity ◽

Current Trend ◽

Operating Conditions ◽

Performance Characteristics ◽

Film Pressure ◽

Content Type ◽

Oil Film ◽

Ellipticity Ratio ◽

Oil Film Pressure

Purpose The current trend of modern industry is to use machineries which rotate at high speed along with the capability of carrying heavy rotor loads. This paper aims at static thermal analysis of two different profiles of non-circular journal bearings – a true elliptical bearing and orthogonal bearing. Design/methodology/approach The Reynolds equation has been solved through finite difference method to compute the oil film pressure. Parabolic temperature profile approximation technique has been used to solve the energy equation and thus used for computation of various bearing performance characteristics such as thermo-hydrodynamic oil film pressure, temperature, load capacity, Sommerfeld number and power loss characteristics across the bearing. The effect of ellipticity ratio on the bearing performance characteristics has also been obtained for both the elliptical and vertical offset bearing using three different commercially available grades of oil (Hydrol 32, 68 and 100). Findings It has been observed that the thermo-hydrodynamic pressure and temperature rise of the oil film is less in orthogonal bearing as compared to the true elliptical bearing for same operating conditions. The effect of ellipticity ratio of non-circularity on bearing performance parameters have been observed to be less in case of elliptical bearing as compared to orthogonal bearing. It has been concluded that though the rise in oil film temperature is high for true elliptical bearing, but still it should be preferred over orthogonal profile under study, as it has comparably good load-carrying capacity. Originality/value The performance parametric analysis will help the designers to select such kind of non-circular journal bearing for various applications.

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Investigation the combined effects of wear and turbulent on the performance of hydrodynamic journal bearing operating with couple stress fluids

International Journal of Structural Integrity ◽

10.1108/ijsi-11-2018-0083 ◽

2019 ◽

Vol 10 (6) ◽

pp. 825-837

Author(s):

Mushrek A. Mahdi ◽

Ahmed Waleed Hussein

Keyword(s):

Couple Stress ◽

Reynolds Equation ◽

Journal Bearing ◽

Performance Characteristics ◽

Turbulent Regime ◽

Hydrodynamic Bearings ◽

Content Type ◽

Hydrodynamic Journal Bearing ◽

Local Reynolds Number ◽

Couple Stress Fluids

Purpose The purpose of this paper is to investigate the combined effect of wear and turbulence on the performance of a hydrodynamic journal bearing operating under Newtonian and couple stress fluids (CSF). Design/methodology/approach The analysis consists of a modified Reynolds equation of incompressible thin viscous films, and the film thickness model taking into account the wear effect. The governing equation was solved numerically using the finite difference approach. Findings The effect of both the wear parameter and the local Reynolds number on the performance characteristics of bearing has been presented and discussed. The obtained results observed that the characteristics of the intact and worn bearing in turbulent and laminar have been enhanced due to the non-Newtonian fluid (CSF) effect. Also, the results display that bearing worn and the turbulent regime cannot be neglected in calculating the performance characteristics of the bearing lubricated with Newtonian and non-Newtonian fluids. The results achieved from this study, specify that the bearing characteristics are significantly affected by these effects. Originality/value The paper investigates the behavior of hydrodynamic bearings considering different aspects simultaneously is interesting, and the application meets the current needs of improvement in modeling hydrodynamic bearings under different conditions.

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Influence of Wear on the Performance of Multirecess Hydrostatic Journal Bearing Operating With Micropolar Lubricant

Journal of Tribology ◽

10.1115/1.4000940 ◽

2010 ◽

Vol 132 (2) ◽

Cited By ~ 25

Author(s):

E. Rajasekhar Nicodemus ◽

Satish C. Sharma

Keyword(s):

Journal Bearing ◽

Dynamic Performance ◽

Flow Equation ◽

Performance Characteristics ◽

Wear Depth ◽

Damping Coefficients ◽

Load Line ◽

Wide Range ◽

Load Arrangement ◽

Stiffness And Damping

The objective of the present work is to study theoretically the influence of wear on the performance of four-pocket capillary-compensated hydrostatic journal bearing operating with micropolar lubricant. In the present study, the lubricant containing additives and contaminants is modeled as micropolar fluid. The modified Reynolds equation for micropolar lubricant is solved using finite element method along with capillary restrictor flow equation as a constraint together with appropriate boundary conditions. The performance characteristics of a capillary-compensated four-pocket worn hydrostatic journal bearing operating with micropolar lubricant have been presented for a wide range of values of nondimensional external load, wear depth parameter, and micropolar parameters. The simulated results have also been presented for two different loading arrangements. In arrangement I, the load line acts through centers of the pockets, whereas in arrangement II, the load line bisects the land between two pockets. The simulated results suggest that a bearing lubricated with lubricant having higher micropolar effect has better static and dynamic performance characteristics as compared with Newtonian lubricant but the bearing lubricated with lubricant having higher micropolar effect is predominantly affected by the wear vis a vis static characteristics parameters as compared with Newtonian lubricant for both loading arrangements. However, in the case of stiffness and damping coefficients, loading arrangement II shows a significant higher enhancement in the value of direct stiffness and damping coefficients in z-direction due to micropolar effect as compared with load arrangement I. And also, the effect of wear on stiffness and damping coefficients in z-direction for bearing operating with micropolar lubricant is of same order as Newtonian lubricant for the loading arrangement II. A similar behavior is observed for the case of stiffness and damping coefficients in x-direction for loading arrangement I.

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