Analyzing Micropolar Lubrication in Noncircular Hybrid Journal Bearings

Dhawan, Rohit; Verma, Suresh

doi:10.1080/10402004.2013.859337

Cited by 19 publications

(11 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…By solving equation (12), the steady-state pressure distribution can be obtained. Then, the static performance characteristics of micropolar lubricated journal bearing such as load carrying capacity and attitude angle based on static pressure can be determined as below.…”

Section: Static Characteristicsmentioning

confidence: 99%

A study on the stability performance of noncircular lobed journal bearings with micropolar lubricant

Mehrjardi

Rahmatabadi

Meybodi

2015

Proceedings of the Institution of Mechanical Engineers, Part J:

View full text Add to dashboard Cite

In this paper, steady-state and stability performance characteristics of circular and noncircular two-, three-, and four-lobe journal bearings with micropolar fluids are presented. For this purpose, lubricating oil containing additives and contaminants is modeled as micropolar fluid. The modified Reynolds equation in dynamical state is obtained using the micropolar lubrication theory, and it is solved by finite element method. The bearing performance characteristics in terms of load carrying capacity, whirl frequency ratio, and critical mass parameter of journal are determined for different values of design parameters such as eccentricity and aspect ratio, preload factor, and micropolarity characteristics of lubricant in terms of material characteristic length and coupling number. Results show that in the case of noncircular bearings, the critical mass to load carrying capacity ratio decreases with increasing of preload factor, so for a constant vertical external load, the stability performance of rotating system can be improved by replacing the circular journal bearing with similar noncircular types. The results compared with Newtonian fluids indicate that micropolar lubricant exhibits better steady-state and dynamic performance. Also, results reveal that upgrading the micropolarity characteristics of lubricant causes increase in critical mass, load carrying capacity but decrease in whirl frequency ratio. It is also observed that the effect of micropolar fluids is more pronounced at high coupling numbers.

show abstract

Section: Static Characteristicsmentioning

confidence: 99%

A study on the stability performance of noncircular lobed journal bearings with micropolar lubricant

Mehrjardi

Rahmatabadi

Meybodi

2015

Proceedings of the Institution of Mechanical Engineers, Part J:

View full text Add to dashboard Cite

show abstract

“…The analysis of multirecessed hybrid conical journal bearing with various restrictors have been carried out by Rajput and Sharma [6,7]. Dhawan and Verma [8] have studied non-circular hybrid journal bearings with micropolar fluid film lubricant. Sharma et al [9] carried out the performance characteristics of multirecess hydrostatic/hybrid flexible journal bearing compensated with membrane type variable flow restrictor.…”

Section: Introductionmentioning

confidence: 99%

Stiffness and damping characteristics of conical multirecess hybrid journal bearing for different load arrangements

2019

View full text Add to dashboard Cite

This paper presents the theoretical analysis on the effect of two different load arrangements for a conical multirecess hybrid journal bearing. For this analysis constant flow valve restrictors are used under micropolar lubricant for different semi cone angles. The modified Reynolds equation using micropolar fluid flow on the conical surface has been solved with the use of FEM and Galerkin's technique applying proper boundary conditions in the iterative scheme. The study suggests that the configuration LA I can be a better alternative as compared to LA II for different semi-cone angles and external load in terms of bearing characteristics. Keywords CFV restrictor • Conical bearing • Micropolar lubrication • FEM List of symbols a b Axial bearing land width, mm A p Area of pocket, mm 2 A b Area of bearing, mm 2 A e Area of each element c Radial clearance, mm C ij Fluid film damping coefficients (N/mm 2), (i, j = x, z) D m Mean journal diameter of conical shaft, mm e Eccentricity, mm F Fluid film reaction F x , F z Fluid film reaction component, N h Fluid film thickness, mm l m ,l Bearing characteristic length L Bearing length, mm M Journal mass, kg p s Supply pressure, N/mm 2 Q Lubricant flow (mm 3 /s) R j Journal radius, mm r Radial coordinate S ij Fluid film stiffness coefficients (N/mm),

show abstract

“…The effect of micropolar parameters on the performance of flexible multirecess hydrostatic journal bearing system was also determined by Verma et al. 17 Dhawan and Verma 18 used the micropolar lubricant to analyze the performance of noncircular hybrid bearings. Rana et al.…”

Section: Introductionmentioning

confidence: 99%

Nonlinear transient analysis of hole-entry journal bearing with constant flow of micropolar fluids

Budheeja

Verma

2018

Proceedings of the Institution of Mechanical Engineers, Part C:

Self Cite

View full text Add to dashboard Cite

The present work deals with study and analysis of a symmetric hybrid journal bearing compensated with constant flow valve restrictor operating with micropolar fluid from stability point of view. The effect of micropolar parameters on the stability of this journal bearing system is presented on the basis of nonlinear transient model. Finite element method has been used to solve modified Reynolds’ equation for the flow of micropolar fluid through the bearing. Computations are done for the static and dynamic characteristics of hole-entry hybrid journal bearing system. The stability characteristics in terms of critical mass of journal, threshold speed, and frequency of whirl are obtained for journal bearing system operating with Newtonian and micropolar fluids and are compared together. Paths of the journal center in the form of trajectories have also been plotted using the journal center coordinates obtained after solving nonlinear equation of motion by fourth-order Runge–Kutta method to find the stability margin of the considered bearing configuration more precisely and easily. Results indicate that micropolar effect causes significant increase in stability margin of the hybrid journal bearing system especially at higher loads. The results also indicate that lubricant flow through the bearing and type of lubricant should be decided in an appropriate manner for the stability of the constant flow valve compensated hybrid journal bearing system.

show abstract

Analyzing Micropolar Lubrication in Noncircular Hybrid Journal Bearings

Cited by 19 publications

References 19 publications

A study on the stability performance of noncircular lobed journal bearings with micropolar lubricant

A study on the stability performance of noncircular lobed journal bearings with micropolar lubricant

Stiffness and damping characteristics of conical multirecess hybrid journal bearing for different load arrangements

Nonlinear transient analysis of hole-entry journal bearing with constant flow of micropolar fluids

Contact Info

Product

Resources

About