Theoretical Investigation of Externally Pressurized Gas-Lubricated Porous Journal Bearing With Surface-Loading Effect

1973 ◽  
Vol 95 (2) ◽  
pp. 195-202 ◽  
Author(s):  
H. Mori ◽  
H. Yabe
Keyword(s):  
Porous Media ◽  
Thin Layer ◽  
Gas Flow ◽  
Flow Model ◽  
Journal Bearing ◽  
Theoretical Calculations ◽  
Surface Loading ◽  
Loading Effect ◽  
Gas Bearing ◽  
Theoretical Results

Externally pressurized porous journal gas bearing is analyzed theoretically in this paper by introducing a flow model, in which the flow in the porous bushing is substituted by a flow in an assumed thin layer. The surface loading effect due to machining is taken into account as the increase of resistance to the gas flow from porous media to bearing clearance. The theoretical results are investigated experimentally, yielding a comparatively good conformity between them enough to certify the analysis. Then, the optimum design conditions of the externally pressurized porous journal gas bearing are obtained by theoretical calculations with considering the surface-loading effect.

A Hydrostatic Bearing With Compressible Fluid for Broad Application

2001 ◽  
Author(s):  
John S. Jacob ◽  
Donald E. Bently ◽  
John J. Yu
Keyword(s):  
Compressible Fluid ◽  
Gas Flow ◽  
Flow Model ◽  
Compressible Fluids ◽  
Environmental Benefits ◽  
Model Parameters ◽  
Broad Application ◽  
Hydrostatic Bearing ◽  
Gas Bearing

The use of relatively inviscid, compressible fluids in externally-pressurized bearings has interesting possibilities for both OEM and retrofit applications. The chance to dramatically reduce mechanical losses and bearing heating, the elimination of oil from the process and installation, and the utilization of compressible process fluids as the supporting medium all have potential economic and environmental benefits. An experimental gas bearing rig was constructed to investigate the feasibility of some general applications. Clearance and orifice dimensions were selected based on a fairly simple gas flow model. Bently-Muszynska model parameters for the hydrostatic gas bearing were obtained through static-pull and non-synchronous perturbation testing.

A New Unified Diffusion—Viscous-Flow Model Based on Pore-Level Studies of Tight Gas Formations

SPE Journal ◽  
2012 ◽  
Vol 18 (01) ◽  
pp. 38-49 ◽  
Author(s):  
Mohammad R. Rahmanian ◽  
Roberto Aguilera ◽  
Apostolos Kantzas
Keyword(s):  
Porous Media ◽  
Viscous Flow ◽  
Flow Regime ◽  
Gas Flow ◽  
Flow Model ◽  
Molecular Flow ◽  
Single Element ◽  
Free Molecular Flow ◽  
Flow Through ◽  
Tight Porous Media

Summary In this study, single-phase gas-flow simulation that considers slippage effects through a network of slots and microfractures is presented. The statistical parameters for network construction were extracted from petrographic work in tight porous media of the Nikanassin Group in the Western Canada Sedimentary Basin (WCSB). Furthermore, correlations between Klinkenberg slippage effect and absolute permeability have been developed as well as a new unified flow model in which Knudsen number acts implicitly as a flow-regime indicator. A detailed understanding of fluid flow at microscale levels in tight porous media is essential to establish and develop techniques for economic flow rate and recovery. Choosing an appropriate equation for flow through a single element of the network is crucial; this equation must include geometry and other structural features that affect the flow as well as all variation of fluid properties with pressure. Disregarding these details in a single element of porous media can easily lead to flow misinterpretation at the macroscopic scale. Because of the wide flow-path-size distribution in tight porous media, a variety of flow regimes can exist in the equivalent network. Two distinct flow regimes, viscous flow and free molecular flow, are in either side of this flow-regime spectrum. Because the nature of these two types of flow is categorically different, finding/adjusting a unified flow model is problematic. The complication stems from the fact that the viscosity concept misses its meaning as the flow regime changes from viscous to free molecular flow in which a diffusion-like mechanism dominates. For each specified flow regime, the appropriate equations for different geometries are studied. In addition, different unified flow models available in the literature are critically investigated. Simulation of gas flow through the constructed network at different mean flow pressures leads to investigating the functionality of the Klinkenberg factor with permeability of the porous media and pore-level structure.

Theoretical Solution as a Boundary Value Problem for Externally Pressurized Porous Gas-Bearings

1965 ◽  
Vol 87 (3) ◽  
pp. 622-630 ◽  
Author(s):  
H. Mori ◽  
H. Yabe ◽  
T. Shibayama
Keyword(s):  
Porous Media ◽  
Boundary Value ◽  
Three Dimensional ◽  
Flow In Porous Media ◽  
Gas Bearings ◽  
Bearing Clearance ◽  
Reasonable Prediction ◽  
Gas Bearing ◽  
Theoretical Results ◽  
Theoretical Standpoint

In this paper, an analytical solution is obtained and discussed for externally pressurized porous gas-bearings from a theoretical standpoint in which the flowing condition in bearing clearance is taken into consideration as a boundary value of the three-dimensional flow in porous media. This approach makes it possible to investigate the characteristics of various bearing configurations with consideration of anisotropy of porous material. And it is assumed that the flow in bearing clearance is laminar and fully viscous while the flow in porous media is characterized by Darcy’s law. The theoretical results are found to give more reasonable prediction of porous gas-bearing performance than those in the previous paper [1].

scholarly journals A dusty gas flow model in porous media

1990 ◽  
Vol 30 (1) ◽  
pp. 21-37 ◽  
Author(s):  
M.H. Hamdan ◽  
R.M. Barron
Keyword(s):  
Porous Media ◽  
Gas Flow ◽  
Flow Model ◽  
Dusty Gas

A Theoretical Analysis Considering Cavitation Occurrence in Oil-Lubricated Spiral-Grooved Journal Bearings With Experimental Verification

2004 ◽  
Vol 126 (3) ◽  
pp. 490-498 ◽  
Author(s):  
Tomoko Hirayama ◽  
Takeo Sakurai ◽  
Hiroshi Yabe
Keyword(s):  
Reynolds Equation ◽  
Flow Model ◽  
Journal Bearing ◽  
Hydrodynamic Lubrication ◽  
Load Capacity ◽  
Theoretical Studies ◽  
Bearing Stiffness ◽  
Hydrodynamic Lubrication Theory ◽  
The Difference ◽  
Theoretical Results

Performances of an oil-lubricated spiral-grooved journal bearing are investigated in this paper with special attention paid to cavitation occurrence. The “equivalent flow model,” which is a theoretical scheme for taking the cavitation occurrence into hydrodynamic lubrication theory, is applied to the analyses by a finite difference treatment of the Reynolds equation that deals with the geometry of a finite number of grooves. The calculated results are compared with experimental results under eccentric states, and verified in terms of cavitation map and pressure distribution. The cavitated area ratio, load capacity and bearing stiffness are also theoretically calculated. The difference between the theoretical results with and without consideration of the cavitation occurrence is considerable, and thus the influence of cavitation occurrence should not be ignored in theoretical studies on bearing characteristics.

MANUFACTURE INVESTIGATION OF CARTRIDGE WITH BOTTOM-MOST PART FLANGE BY DIRECT EXTRUSION WITH COUNTERPUNCH. REPORT 18. EXPERIMENTAL CHECK OF THEORETICAL RESULTS FOR DIFFERENT HOLLOW RADIUSES AND BOTTOM-MOST PART THICKNESSES

2020 ◽  
Vol 0 (9) ◽  
pp. 16-23
Author(s):  
A. L. Vorontsov ◽  
◽  
I. A. Nikiforov ◽  
Keyword(s):  
Strain Hardening ◽  
Theoretical Calculations ◽  
High Accuracy ◽  
Geometric Parameters ◽  
Strength Characteristics ◽  
Experimental Check ◽  
Hardening Material ◽  
Direct Extrusion ◽  
Theoretical Results

The results of an experimental check of the obtained theoretical formulae allowing us to determine the most important parameters of extrusion cartridges with a counterpunch for different hollow radiuses and bottom-most part thicknesses are presented. Characteristics of used tools, geometric parameters of extrusion experiments, strength characteristics of deformed materials and lubricants are described in detail. Both strain-hardening material and strain-unhardening material were studied. Methodology of the theoretical calculations is demonstrated in detail. High accuracy of the obtained design formulae was confirmed.

Transient response of the 1-st order dynamic system with fluctuating parameters

1979 ◽  
Vol 44 (7) ◽  
pp. 2184-2195
Author(s):  
Vladimír Herles ◽  
Jan Čermák ◽  
Antonín Havlíček
Keyword(s):  
Dynamic System ◽  
Dynamic Behavior ◽  
Transient Response ◽  
Flow Model ◽  
Stirred Tank ◽  
Order System ◽  
Random Parameters ◽  
Stirred Tank Reactor ◽  
Tank Reactor ◽  
Theoretical Results

The paper deals with the analysis of the dynamic behavior of the 1st order system with two random parameters. The theoretical results have been compared with experiments on flow model of a stirred tank reactor.

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