Axial Current Induced Pinch Effect on the Squeeze-Film Behavior for Porous Annular Disks

1975 ◽  
Vol 97 (1) ◽  
pp. 130-133 ◽  
Author(s):  
J. L. Gupta ◽  
P. C. Sinha

An analysis of the effect of axial current induced pinch on the squeeze-film behavior between two annular disks, when the upper disk which has a porous facing and is parallel to the stationary nonporous disk moves normal to itself approaching the lower disk, is presented. The analytical results for the pressure distribution, load-carrying capacity, and the film thickness as a function of time are obtained and the effect of pinch on these quantities is studied. It is found that a load proportional to the square of the axial current can be sustained even when there is no flow.

1970 ◽  
Vol 92 (4) ◽  
pp. 593-596 ◽  
Author(s):  
Hai Wu

An analysis is made of the squeeze-film behavior between two annular disks when one disk has a porous facing. The problem is solved analytically. Results are presented for pressure distribution, load-carrying capacity, and film thickness as functions of time.


1972 ◽  
Vol 94 (1) ◽  
pp. 64-68 ◽  
Author(s):  
Hai Wu

The squeeze film between two rectangular plates when one has a porous facing is studied theoretically. The problem is described by the modified Reynolds equation in the film region and the Laplace equation in the porous region. Results are presented for pressure distribution, load-carrying capacity, and film thickness as functions of time in series form. The effect of the porous facing on the squeeze film behavior is discussed and found to be important.


Author(s):  
H Aminkhani ◽  
M Daliri

The paper shows the combined effects of couple stress fluids and lubricant viscosity variation with pressure in squeeze film performance of parallel triangular plates. By solving Reynolds equation and using perturbation method, the pressure distribution is obtained with consideration of viscosity variation with pressure. Also, with integrating pressure in the film region, load-carrying capacity is derived. A fourth-order Rang–Kutta is used to solve the nonlinear differential equation between lubricant film thickness and time. Various cases of couple stress, iso-viscous and piezo-viscous contributions are analyzed. According to the results, it is found that using couple stress fluid as a lubricant and considering viscosity–pressure dependency will increase characteristics of the squeeze film such as load-carrying capacity, pressure distribution, and triangular plates moving time, significantly as compared to the classical Newtonian iso-viscous lubricant.


2016 ◽  
Vol 10 (1) ◽  
pp. 50-55 ◽  
Author(s):  
Anna Walicka ◽  
Edward Walicki

Abstract In the paper the influence of both bearing surfaces roughness and porosity of one bearing surface on the pressure distribution and load-carrying capacity of a thrust bearing surfaces is discussed. The equations of motion of a pseudo-plastic fluid of Rotem-Shinnar, are used to derive the Reynolds equation. After general considerations on the flow in a bearing clearance and in a porous layer using the Morgan-Cameron approximation and Christensen theory of hydrodynamic lubrication the modified Reynolds equation is obtained. The analytical solutions of this equation for the cases of squeeze film bearing and externally pressurized bearing are presented. As a result one obtains the formulae expressing pressure distribution and load-carrying capacity. Thrust radial bearing with squeezed film is considered as a numerical example.


1975 ◽  
Vol 97 (4) ◽  
pp. 635-637 ◽  
Author(s):  
M. Balaram

An analysis of micropolar squeeze films is presented. Expressions are derived for calculating the pressure, the load-carrying capacity of the squeeze film and film thickness–time relationship. Numerical results computed from these expressions reveal that fluid microstructure improves the squeeze film action and increases the load-carrying capacity of the squeeze film, while the load-carrying capacity reduces rapidly with an increase in fluid substructure.


2014 ◽  
Vol 19 (4) ◽  
pp. 809-822
Author(s):  
A. Walicka ◽  
E. Walicki ◽  
P. Jurczak ◽  
J. Falicki

Abstract In the paper the influence of bearing surfaces roughness on the pressure distribution and load-carrying capacity of a thrust bearing is discussed. The equations of motion of an Ellis pseudo-plastic fluid are used to derive the Reynolds equation. After general considerations on the flow in a bearing clearance and using the Christensen theory of hydrodynamic rough lubrication the modified Reynolds equation is obtained. The analytical solutions of this equation for the cases of a squeeze film bearing and an externally pressurized bearing are presented. As a result one obtains the formulae expressing pressure distribution and load-carrying capacity. A thrust radial bearing is considered as a numerical example.


2014 ◽  
Vol 19 (4) ◽  
pp. 795-808
Author(s):  
A. Walicka ◽  
E. Walicki ◽  
P. Jurczak ◽  
J. Falicki

Abstract In the paper the effect of both bearing surfaces and the porosity of one bearing surface on the pressure distribution and load-carrying capacity of a squeeze film bearing is discussed. The equations of motion of a Bingham fluid in a bearing clearance and in a porous layer are presented. Using the Morgan-Cameron approximation and Christensen theory of rough lubrication the modified Reynolds equation is obtained. The analytical solutions of this equation for a squeeze film bearing are presented. As a result one obtains the formulae expressing pressure distribution and load-carrying capacity. A thrust radial bearing is considered as a numerical example.


2020 ◽  
Vol 75 (6) ◽  
pp. 533-542
Author(s):  
Poosan Muthu ◽  
Vanacharla Pujitha

AbstractThe influence of concentration of solute particles on squeeze film lubrication between two poroelastic surfaces has been analyzed using a mathematical model. Newtonian viscous fluid is considered as a lubricant whose viscosity varies linearly with concentration of suspended solute particles. Convection-diffusion model is proposed to study the concentration of solute particles and is solved using finite difference method of Crank–Nicolson scheme. An iterative procedure is used to get the solution for concentration, pressure and velocity components in film region. It has been observed that load carrying capacity decreases as the concentration of solute particles in the fluid film decreases. Further, the concentration of suspended solute particles decreases as the permeability of the poroelastic plate increases and these results may be useful in understanding the mechanism of human joint.


Author(s):  
Hanumagowda Bannihalli Naganagowda ◽  
Sreekala Cherkkarathandayan Karappan

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.


2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Binbin Su ◽  
Xianghe Zou ◽  
Lirong Huang

Purpose This paper aims to investigate the squeeze film lubrication properties of hexagonal patterned surface inspired by the epidermis structure of tree frog’s toe pad and numerically explore the working mechanism of hexagonal micropillar during the acquisition process of high adhesive and friction for wet contacts. Design/methodology/approach A two-dimensional elastohydrodynamic numerical model is employed for the squeezing contacts. The pressure distribution, load carrying capacity and liquid flow rate of the squeeze film are obtained through a simultaneous solution of the two-dimensional Reynolds equation and elasticity deformation equations. Findings Higher pressure is found to be longitudinally distributed across individual hexagonal pillar, with pressure peak emerging at the center of hexagonal pillar. Expanding the area density and shrinking the channel depth or initial film thickness will improve the magnitude of squeezing pressure. Relatively lower pressure is generated inside interconnected channels, which reduces the load carrying capacity of the squeeze film. Meanwhile, the introduction of microchannel is revealed to downscale the total mass flow rate of squeezing contacts. Originality/value This paper provides a good proof for the working mechanism of surface microstructures during the acquisition process of high adhesive and friction for wet contacts.


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