Squeeze Film Theory for Micropolar Fluids

1976 ◽  
Vol 98 (1) ◽  
pp. 139-144 ◽  
Author(s):  
J. Prakash ◽  
P. Sinha
Keyword(s):  
Thin Films ◽  
Flow Behavior ◽  
Film Theory ◽  
Continuum Theory ◽  
Squeeze Film ◽  
Micropolar Fluids ◽  
Fluid Theory ◽  
Film Characteristics ◽  
Analytical Expressions ◽  
Circular Disks

Needs’ experimental results on thin films deviate considerably from those predicted by the classical theory when the film thickness is less than 0.00127 mm. In recent years there has been a tendency to attribute this deviation to the inadequacy of the classical continuum theory to describe the fluid flow behavior when confined to narrow passages. In this paper the micropolar fluid theory is applied to the squeeze films for circular disks to explain Needs’ findings. An excellent qualitative agreement is found to exist between the results based on this analysis and Needs’ results. Analytical expressions are obtained for various squeeze film characteristics and effect of microstructure elaborated through graphs.

Stochastic Reynolds equation for the combined effects of piezo-viscous dependency and squeeze-film lubrication of micropolar fluids on rough porous circular stepped plates

2021 ◽  
pp. 135065012110224
Author(s):  
Hanumagowda Bannihalli Naganagowda ◽  
Sreekala Cherkkarathandayan Karappan
Keyword(s):  
Carrying Capacity ◽  
Stochastic Approach ◽  
Squeeze Film ◽  
Closed Form Expression ◽  
Load Carrying Capacity ◽  
Micropolar Fluids ◽  
Pressure Dependent Viscosity ◽  
Load Carrying ◽  
Dependent Viscosity ◽  
Film Characteristics

The aim of this paper is to presents a theoretical analysis on squeeze-film characteristics of a rough porous circular stepped plate in the vicinity of pressure-dependent viscosity and lubrication by micropolar fluids. A closed-form expression for non-dimensional pressure, load, and squeezing time is derived based on Eringen’s theory, Darcy’s equation, and Christensen’s stochastic approach. Results indicate that the effects of pressure-dependent viscosity, surface roughness, and micropolar fluids play an important role in increasing the load-carrying capacity and squeezing time, whereas the presence of porous media decreases the load-carrying capacity and squeezing time of the rough porous circular stepped plates.

Non-Newtonian Micropolar Fluid Squeeze Film Between Conical Plates

2012 ◽  
Vol 67 (6-7) ◽  
pp. 333-337 ◽  
Author(s):  
Jaw-Ren Lin ◽  
Chia-Chuan Kuo ◽  
Won-Hsion Liao ◽  
Ching-Been Yang
Keyword(s):  
Micropolar Fluid ◽  
Reynolds Equation ◽  
Fluid Model ◽  
Load Capacity ◽  
Numerical Results ◽  
Squeeze Film ◽  
Micropolar Fluids ◽  
Newtonian Case ◽  
Film Characteristics ◽  
Film Lubrication

By applying the micropolar fluid model of Eringen (J. Math. Mech. 16, 1 (1966) and Int. J. Mech. Sci. 31, 605 (1993)), the squeeze film lubrication problems between conical plates are extended in the present paper. A non-Newtonian modified Reynolds equation is derived and applied to obtain the solution of squeeze film characteristics. Comparing with the traditional Newtonian case, the non-Newtonian effects of micropolar fluids are found to enhance the load capacity and lengthen the approaching time of conical plates. Some numerical results are also provided in tables for engineer applications

Derivation of non-Newtonian squeeze-film Reynolds equation between convex surfaces and application to two different cylinders

2007 ◽  
Vol 221 (7) ◽  
pp. 813-821 ◽  
Author(s):  
J-R Lin
Keyword(s):  
Couple Stress ◽  
Reynolds Equation ◽  
Continuum Theory ◽  
Type Equation ◽  
Squeeze Film ◽  
Convex Surfaces ◽  
Couple Stresses ◽  
Load Carrying ◽  
Film Characteristics ◽  
Couple Stress Fluids

The derivation of non-Newtonian squeeze-film Reynolds-type equation between two convex surfaces and its application are of interest in the present study. Based upon the Stokes micro-continuum theory, the non-Newtonian squeeze-film Reynolds-type equation between two convex surfaces is derived to take into account the effects of couple stresses resulting from the lubricant blended with various additives. This non-Newtonian squeeze-film Reynolds-type equation is applicable to squeeze-film bearings lubricated with couple stress fluids when the general upper film shape and the lower film shape are specified. To guide the use of the equation, the squeeze-film mechanism between two different cylinders of infinite width with non-Newtonian couple stress fluids is illustrated. Comparing with the Newtonian-lubricant case, the presence of non-Newtonian couple stresses provides an increase in the load-carrying capacity, and therefore lengthens the approaching time. In addition, the effects of couple stresses on the squeeze film characteristics are more pronounced at lower squeeze-film height with larger couple stress parameters and larger radius ratios of cylinders. As the value of radius ratio approaches infinity, the present results agree closely with those of the previous studies by Hamrock [6] and by Lin et al. [19], respectively; it provides a support to the present study.

Non-Newtonian Inertia Squeeze Film Characteristics in Rectangular Stepped Plates

2015 ◽  
Vol 775 ◽  
pp. 73-77
Author(s):  
Jaw Ren Lin ◽  
Shu Ting Hu
Keyword(s):  
Normal Load ◽  
Load Capacity ◽  
Continuum Theory ◽  
Squeeze Film ◽  
Fluid Inertia ◽  
Inertia Effects ◽  
Lubrication Equation ◽  
Momentum Integral ◽  
Film Characteristics ◽  
Inertia Forces

A study of non-Newtonian inertia squeeze film in rectangular stepped plates has been presented in this paper. Applying the momentum integral method incorporating the micro-continuum theory of non-Newtonian fluids, a non-Newtonian inertia lubrication equation is derived. It is found that the fluid inertia effects yield in a higher normal load capacity as well as a longer squeeze film time as compared to the non-Newtonian stepped squeeze film in the absence of fluid inertia forces.

A comparison of squeeze-film theory with measurements on a microstructure

1993 ◽  
Vol 36 (1) ◽  
pp. 79-87 ◽  
Author(s):  
M. Andrews ◽  
I. Harris ◽  
G. Turner
Keyword(s):  
Film Theory ◽  
Squeeze Film
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