A Theory of Hydrodynamic Lubrication Involving the Mixture of Two Fluids

1994 ◽  
Vol 61 (3) ◽  
pp. 634-641 ◽  
Author(s):  
F. Dai ◽  
M. M. Khonsari
Keyword(s):  
Continuum Mechanics ◽  
Newtonian Fluid ◽  
Journal Bearing ◽  
Hydrodynamic Lubrication ◽  
Incompressible Fluids ◽  
Theoretical Development ◽  
Governing Equations ◽  
Power Law Fluid ◽  
Two Fluids ◽  
Special Cases

Based on the principles of continuum mechanics, we drive the governing equations for the hydrodynamic lubrication involving the mixture of two incompressible fluids. The governing equations are general in the sense that they can be applied to the mixture of any simple non-Newtonian fluid with a Newtonian fluid. A mixture thus formed is considered to be nonhomogeneous and non-Newtonian. In the theoretical development, the interaction between the constituents is taken into consideration. It is shown that a number of currently available models are special cases of the theory presented in this paper. As an example, results are presented for journal bearing performance lubricated with a mixture of a power-law fluid mixed with Newtonian oil.

Surface Roughness Effects in Hydrodynamic Lubrication Involving the Mixture of Two Fluids

1998 ◽  
Vol 120 (4) ◽  
pp. 772-780 ◽  
Author(s):  
Wang-Long Li
Keyword(s):  
Surface Roughness ◽  
Newtonian Fluid ◽  
Power Law ◽  
Volume Fraction ◽  
Hydrodynamic Lubrication ◽  
Stress Factors ◽  
Function Technique ◽  
Perturbation Approach ◽  
Power Law Fluid ◽  
Special Cases

In this paper, the relations expressing the effects of surface roughness and homogeneous mixture (the mixture of power-law fluid inserted into a Newtonian fluid) on the roughness-induced flow factors are derived. A coordinate transformation is utilized to simplify the derivation. By using the perturbation approach incorporated with Green function technique, the flow factors and shear stress factors are derived and expressed as functions of the volume fraction of the power-law fluid in the mixture (υ p), the viscosity ratio of the power-law fluid to that of the Newtonian fluid (N or μp*), the flow behavior index of the power-law fluid (η), the Peklenik numbers (γi) and the standard deviations (σl) of each surface. A form of the average Reynolds equation is then obtained. It is shown that a number of currently available models are special cases of the theory presented here. Finally, the performance of a journal bearing is discussed.

A Contribution to the Analysis of the Thermo-Hydrodynamic Lubrication of Porous Self-Lubricating Journal Bearings

2010 ◽  
Vol 297-301 ◽  
pp. 618-623 ◽  
Author(s):  
S. Boubendir ◽  
Salah Larbi ◽  
Rachid Bennacer
Keyword(s):  
Thermal Effects ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Hydrodynamic Lubrication ◽  
Load Capacity ◽  
Porous Matrix ◽  
Journal Bearings ◽  
Governing Equations ◽  
Hydrodynamic Analysis ◽  
Result Show

In this work the influence of thermal effects on the performance of a finite porous journal bearing has been investigated using a thermo-hydrodynamic analysis. The Reynolds equation of thin viscous films is modified taking into account the oil leakage into the porous matrix, by applying Darcy’s law to determine the fluid flow in the porous media. The governing equations were solved numerically using the finite difference approach. Obtained result show a reduction in the performance of journal bearings when the thermal effects are accounted for and, this reduction is greater when the load capacity is significant.

A Non-Newtonian Fluid Flow Model for the Slip Condition on Blood Flow through a Stenosed Artery using Power-law Fluid

2018 ◽  
Vol 9 (7) ◽  
pp. 871-879
Author(s):  
Rajesh Shrivastava ◽  
R. S. Chandel ◽  
Ajay Kumar ◽  
Keerty Shrivastava and Sanjeet Kumar
Keyword(s):  
Blood Flow ◽  
Fluid Flow ◽  
Newtonian Fluid ◽  
Power Law ◽  
Flow Model ◽  
Slip Condition ◽  
Power Law Fluid ◽  
Stenosed Artery ◽  
Flow Through

scholarly journals Mathematical study on two-fluid model for flow of K–L fluid in a stenosed artery with porous wall

2021 ◽  
Vol 3 (4) ◽  
Author(s):  
R. Ponalagusamy ◽  
Ramakrishna Manchi
Keyword(s):  
Theoretical Study ◽  
Fluid Model ◽  
Porous Wall ◽  
Governing Equations ◽  
Rate Of Increase ◽  
Special Cases ◽  
Stenosed Artery ◽  
Flow Through ◽  
Two Fluid Model ◽  
Two Fluid

AbstractThe present communication presents a theoretical study of blood flow through a stenotic artery with a porous wall comprising Brinkman and Darcy layers. The governing equations describing the flow subjected to the boundary conditions have been solved analytically under the low Reynolds number and mild stenosis assumptions. Some special cases of the problem are also presented mathematically. The significant effects of the rheology of blood and porous wall of the artery on physiological flow quantities have been investigated. The results reveal that the wall shear stress at the stenotic throat increases dramatically for the thinner porous wall (i.e. smaller values of the Brinkman and Darcy regions) and the rate of increase is found to be 18.46% while it decreases for the thicker porous wall (i.e. higher values of the Brinkman and Darcy regions) and the rate of decrease is found to be 10.21%. Further, the streamline pattern in the stenotic region has been plotted and discussed.

scholarly journals Mathematical Modeling of Journal Bearing Lubricated with Non-Newtonian Fluid

2021 ◽  
Vol 43 (4) ◽  
pp. 615-623
Author(s):  
M. Kouider ◽  
Z. Djallel ◽  
Y. Abdelkader ◽  
K. Sahraoui
Keyword(s):  
Mathematical Modeling ◽  
Newtonian Fluid ◽  
Journal Bearing

scholarly journals Entropy Analysis on a Three-Dimensional Wavy Flow of Eyring–Powell Nanofluid: A Comparative Study

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Arshad Riaz ◽  
Ahmed Zeeshan ◽  
M. M. Bhatti
Keyword(s):  
Viscous Dissipation ◽  
Newtonian Fluid ◽  
Entropy Generation ◽  
Pressure Rise ◽  
Software Tool ◽  
Bejan Number ◽  
Mathematical Treatment ◽  
Cylindrical Domain ◽  
Special Cases ◽  
The Impact

The thermal management of a system needs an accurate and efficient measurement of exergy. For optimal performance, entropy should be minimized. This study explores the enhancement of the thermal exchange and entropy in the stream of Eyring–Powell fluid comprising nanoparticles saturating the vertical oriented dual cylindrical domain with uniform thermal conductivity and viscous dissipation effects. A symmetrical sine wave over the walls is used to induce the flow. The mathematical treatment for the conservation laws are described by a set of PDEs, which are, later on, converted to ordinary differential equations by homotopy deformations and then evaluated on the Mathematica software tool. The expression of the pressure rise term has been handled numerically by using numerical integration by Mathematica through the algorithm of the Newton–Cotes formula. The impact of the various factors on velocity, heat, entropy profile, and the Bejan number are elaborated pictorially and tabularly. The entropy generation is enhanced with the variation of viscous dissipation but reduced in the case of the concentration parameter, but viscous dissipation reveals opposite findings for the Newtonian fluid. From the abovementioned detailed discussion, it can be concluded that Eyring–Powell shows the difference in behavior in the entropy generation and in the presence of nanoparticles due to the significant dissipation effects, and also, it travels faster than the viscous fluid. A comparison between the Eyring-Powell and Newtonian fluid are also made for each pertinent parameter through special cases. This study may be applicable for cancer therapy in biomedicine by nanofluid characteristics in various drugs considered as a non-Newtonian fluid.

A New Computational Method for Free Surface Problems

2005 ◽  
Author(s):  
Jeremy Rice ◽  
Amir Faghri
Keyword(s):  
Free Surface ◽  
Capillary Tube ◽  
Accurate Method ◽  
Computational Method ◽  
Surface Velocity ◽  
Governing Equations ◽  
Two Fluids ◽  
Correction Technique ◽  
Instability Growth ◽  
A New Technique

A new technique, called the surface velocity correction technique (SVC), is developed to track a free surface such as a liquid-vapor interface. SVC is a computationally inexpensive, and accurate method to capture interfacial fluid phenomena. This method uses a finite volume technique to discretize the governing equations, and a semi-Legrangian mesh to locate the interface between two fluids. The effectiveness of this technique is demonstrated through several classical examples and the results are also compared to both analytical and VOF solutions. The examples include: the shape of a meniscus in a capillary tube in mechanical equilibrium, the rise of a meniscus in a capillary tube, and the instability growth of a free flowing cylindrical column of fluid.

On Suddenly Expanding Non-Isothermal Pipe Flows of a Bingham Fluid

1999 ◽  
Author(s):  
Khaled J. Hammad
Keyword(s):  
Heat Transfer ◽  
Newtonian Fluid ◽  
Transfer Problem ◽  
Numerical Technique ◽  
Complex Nature ◽  
Brinkman Number ◽  
Governing Equations ◽  
Heat Transfer Characteristics ◽  
Flow And Heat Transfer ◽  
Pipe Expansion

Abstract The non-isothermal laminar flow of the Bingham non-Newtonian fluid through a sudden pipe expansion is investigated. The governing equations of conservation of mass, momentum and energy are solved using the finite-difference numerical technique. The effects of non-dimensional yield stress, Reynolds number, Prandtl number and Brinkman number on the flow and heat transfer characteristics are studied. The obtained results indicate the complex nature of the present non-Newtonian fluid flow and heat transfer problem and reveal new features not encountered in the case of Newtonian fluids.

Performance of Stern Tube Bearings under Different Lubrication and Operating Conditions

2009 ◽  
Author(s):  
Jan H. Andersen ◽  
Hiroyuki Sada ◽  
Seiji Yamajo
Keyword(s):  
Journal Bearing ◽  
Hydrodynamic Lubrication ◽  
Journal Bearings ◽  
Operating Conditions ◽  
Water Soluble ◽  
Analysis Tool ◽  
Test Rig ◽  
Experimental Performance ◽  
Shaft Alignment ◽  
Alignment Analysis

This paper presents the results of an investigation into the theoretical and experimental performance of oil lubricated journal bearings. DNV has developed a new calculation tool for the analysis of journal bearing performance as part of shaft alignment analysis. The results of the calculation tool have been compared to other research and analysis methods under static and dynamic conditions. In addition, white metal bearings were tested with decreasing Sommerfeld number until loss of hydrodynamic lubrication. The experiments were carried out in a bearing test rig and with three different lubricants, normal mineral oil, emulsifying oil, and water-soluble oil. The tests were done with increasing water content in the lubricant. Results from the test were compared with calculation using the DNV analysis tool.

Sign in / Sign up

Export Citation Format

Share Document