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

2019 ◽  
Vol 41 (9) ◽  
Author(s):  
Biplab Bhattacharjee ◽  
Prasun Chakraborti ◽  
Kishan Choudhuri
Keyword(s):  
Theoretical Analysis ◽  
Micropolar Fluid ◽  
Journal Bearing

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

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.

scholarly journals Influence of Nano-Fluid Lubrication On Single Porous-Layered Journal Bearing: A Hypothetical Approach

2021 ◽  
Author(s):  
BIPLAB BHATTACHARJEE ◽  
PRASUN CHAKRABORTI ◽  
KISHAN CHOUDHURY
Keyword(s):  
Mathematical Model ◽  
Boundary Conditions ◽  
Micropolar Fluid ◽  
Journal Bearing ◽  
Performance Characteristics ◽  
Published Data ◽  
Nano Fluid ◽  
Nano Lubricant ◽  
Output Characteristics ◽  
Modified Darcy’S Law

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.

Separation Cavitation; Solutions for the Infinite Width Cylinder-Plane and Journal-Bearing Configurations

1973 ◽  
Vol 15 (3) ◽  
pp. 237-239 ◽  
Author(s):  
C. M. Taylor
Keyword(s):  
Boundary Condition ◽  
Theoretical Analysis ◽  
Experimental Work ◽  
Journal Bearing ◽  
Low Load

Theoretical analysis of the infinite width cylinder-plane and journal-bearing configurations is undertaken using the separation cavitation boundary condition. The results could form the basis of experimental work designed to check the appropriateness of the boundary condition for low-load situations.

Steady-State and Dynamic Behaviour of Multi-Recess Hybrid Oil Journal Bearings

1979 ◽  
Vol 21 (5) ◽  
pp. 345-351 ◽  
Author(s):  
M. K. Ghosh ◽  
B. C. Majumdar ◽  
J. S. Rao
Keyword(s):  
Perturbation Theory ◽  
Steady State ◽  
Theoretical Analysis ◽  
Dynamic Behaviour ◽  
Journal Bearing ◽  
Load Capacity ◽  
Journal Bearings ◽  
Time Dependent ◽  
Damping Coefficients ◽  
Stiffness And Damping

A theoretical analysis of the steady-state and dynamic characteristics of multi-recess hybrid oil journal bearings is presented. A perturbation theory for small vibrations is used to solve an incompressible, finite journal bearing with a time-dependent term. Load capacity, attitude angle, friction parameter, stiffness and damping coefficients are evaluated for a capillary-compensated bearing.

Comparison of Effects of Dimensional Manufacturing Tolerances and Journal Out-of-Roundness on Stability of Hydrodynamic Journal Bearing System

2011 ◽  
Vol 121-126 ◽  
pp. 1966-1971
Author(s):  
Wu Bin Xu ◽  
De Jian Zhou ◽  
Peter Ogrodnik ◽  
Mike Goodwin
Keyword(s):  
Theoretical Analysis ◽  
Taguchi Method ◽  
Journal Bearing ◽  
Journal Bearings ◽  
System Stability ◽  
Design Stage ◽  
Analysis Method ◽  
Manufacturing Tolerances ◽  
Hydrodynamic Journal Bearing ◽  
Bearing System

The manufacturing tolerances of a hydrodynamic journal bearing system are inevitable in manufacturing process. To examine and understand the effect of manufacturing tolerances on the system stability can help engineers to confidently choose reasonable tolerances at design stage. This study presented a theoretical analysis method to determine and compare the effects of dimensional manufacturing tolerances and journal out-of-roundness on system stability by Taguchi method. The results show that the journal out-of-roundness has the most significant effect on the system stability and the journal out-of-roundness appears to stabilize the system. The authors suggest that both dimensional manufacturing tolerances and journal roundness should be taken into account in the design of cylindrical journal bearings.

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

2018 ◽  
Vol 233 (1) ◽  
pp. 350-368 ◽  
Author(s):  
Kamal Budheeja ◽  
Suresh Verma
Keyword(s):  
Micropolar Fluid ◽  
Journal Bearing ◽  
Stability Margin ◽  
Constant Flow ◽  
Micropolar Fluids ◽  
Stability Point ◽  
Nonlinear Transient ◽  
The Stability ◽  
Bearing System ◽  
Flow Valve

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.

Rayleigh Step Journal Bearing, Part II—Incompressible Fluid

1969 ◽  
Vol 91 (4) ◽  
pp. 641-650 ◽  
Author(s):  
B. J. Hamrock ◽  
W. J. Anderson
Keyword(s):  
Theoretical Analysis ◽  
Film Thickness ◽  
Journal Bearing ◽  
Load Capacity ◽  
Maximum Load ◽  
Single Step ◽  
Thickness Ratio ◽  
Infinite Length ◽  
One Step ◽  
Bearing Part

A theoretical analysis of the pressure distribution, load, capacity, and attitude angle for a single-step concentric as well as a multistep infinite length eccentric Rayleigh step journal bearing is performed. The results from the single-step concentric analysis indicated that the maximum load capacity is obtained when the film thickness ratio is 1.7 and the ratio of the angle subtended by the ridge to the angle subtended by the pad is 0.35. The results from the infinite length eccentric analysis indicated that one step placed around the journal was optimal. For eccentricity ratios greater than or equal to 0.2 the maximum load occurred for a bearing without a step or a Sommerfeld bearing. For eccentricity ratios less than 0.2 the optimal film thickness ratio is 1.7 while there are three optimal ratios of angle subtended by the ridge to the angle subtended by the pad of 0.4, 0.45, and 0.5 depending on whether load capacity or stability or both load capacity and stability is more important in the application being considered.

Cyclic Squeeze Films in Micropolar Fluid Lubricated Journal Bearings

1976 ◽  
Vol 98 (3) ◽  
pp. 412-417 ◽  
Author(s):  
J. Prakash ◽  
P. Sinha
Keyword(s):  
Dynamic Behavior ◽  
Dynamic Loading ◽  
Micropolar Fluid ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Detailed Consideration ◽  
Sinusoidal Load ◽  
Fluid Theory ◽  
Curve Form

The Reynolds equation for the general case of dynamic loading is derived for fluid suspensions, using the micropolar fluid theory. Detailed consideration is given to the dynamic behavior of squeeze films in journal bearings under a fluctuating load with no journal rotation. The characteristics of an infinitely long journal bearing under a cyclic sinusoidal load are shown in curve form, so as to elaborate the micropolar effects.

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