Effects of a Groove on the Behavior of a Squeeze Film Between a Grooved and a Plain Rotating Annular Disk

1999 ◽  
Vol 121 (4) ◽  
pp. 808-815 ◽  
Author(s):  
M. Mahbubur Razzzaque ◽  
Takahisa Kato
Keyword(s):  
Film Thickness ◽  
Power Dissipation ◽  
Applied Load ◽  
Reynolds Equation ◽  
Fluid Film ◽  
Squeeze Film ◽  
Angular Orientation ◽  
Governing Equations ◽  
Annular Disk

A model simulating the squeezing process of an annular disk rotating against a grooved counterpart has been developed. Grooving effects are incorporated using the narrow groove assumption. Disks are considered impermeable, rigid, perfectly aligned, and smooth. It is assumed that the fluid film is isothermal and obeys Reynolds equation. The governing equations derived from the model are solved numerically. The effects of groove geometry, orientation and applied load on film thickness, transmitted torque, speed, squeeze time, and viscous power dissipation have been calculated and analyzed. It has been found that angular orientation significantly affects the squeezing process. Squeeze time and power dissipation are less for grooves with angular orientation in the range 40–60 deg.

The Prediction of Film Thickness in a Mechanical face Seal with Circumferential Waviness on both the face and the seat

1982 ◽  
Vol 24 (1) ◽  
pp. 37-43 ◽  
Author(s):  
A. V. Ruddy ◽  
D. Dowson ◽  
C. M. Taylor
Keyword(s):  
Film Thickness ◽  
Reynolds Equation ◽  
Closed Loop ◽  
Lubrication Theory ◽  
Fluid Film ◽  
Squeeze Film ◽  
Two Dimensional ◽  
Face Seal ◽  
The Face ◽  
Mechanical Face Seal

The effect of two-period waviness on both the face and the seat of a mechanical face seal is examined theoretically in this paper. A closed-loop cyclic solution of the two-dimensional Reynolds' equation including squeeze-film effects is described. Results for a 45 mm diameter seal are presented which show that squeeze-film effects play an important role in protecting the fluid-film over parts of the cycle where the entraining effect is small. The analysis can be extended to allow for misalignment of the sealing faces and for the incorporation of mixed-lubrication theory.

A Study of Thermohydrodynamic Squeeze Films

1974 ◽  
Vol 96 (2) ◽  
pp. 198-205 ◽  
Author(s):  
S. M. Rohde ◽  
H. A. Ezzat
Keyword(s):  
Heat Conduction Equation ◽  
Reynolds Equation ◽  
Energy Equation ◽  
Time Dependent ◽  
Fluid Film ◽  
Squeeze Film ◽  
3 Dimensional ◽  
Temperature Distributions ◽  
Film Parameter ◽  
The Mathematical Model

This paper presents an analysis of the thermohydrodynamic performance of squeeze films. The mathematical model consists of a 3-dimensional Reynolds equation, a 3-dimensional time dependent energy equation, and a 3-dimensional time dependent heat conduction equation. The system of equations is solved numerically. Fluid film pressure and temperature distributions and the temperature distribution in the solids are presented. Fluid film velocity profiles as a function of time are also shown. The load-time characteristics for different operative conditions are studied. It is shown that a thermohydrodynamic squeeze-film parameter can give rise to a phenomenon which radically changes the fluid film performance.

scholarly journals Hydrodynamic lubrication of rough surfaces

1982 ◽  
Vol 383 (1785) ◽  
pp. 439-446 ◽  
Keyword(s):  
Surface Roughness ◽  
Film Thickness ◽  
Reynolds Equation ◽  
Hydrodynamic Lubrication ◽  
Rough Surfaces ◽  
Homogenization Method ◽  
Squeeze Film ◽  
Spatial Average

Using the two-space homogenization method we derive an averaged Reynolds equation that is correct to O (< H 6 > — < H 3 > 2 ), where H is the total film thickness and the angle brackets denote a spatial average. Applications of this mean Reynolds equation to a squeeze-film bearing with a sinusoidal or an isotropic surface roughness are discussed.

Theoretical Studies of a Continuously Adjustable Hydrodynamic Fluid Film Bearing

2001 ◽  
Vol 124 (1) ◽  
pp. 203-211 ◽  
Author(s):  
J. K. Martin ◽  
D. W. Parkins
Keyword(s):  
Film Thickness ◽  
Reynolds Equation ◽  
Solution Procedure ◽  
Fluid Film ◽  
Theoretical Studies ◽  
Analysis Model ◽  
Operating Characteristics ◽  
Hydrodynamic Bearing ◽  
Wide Range ◽  
Fluid Film Thickness

Principles of a continuously adjustable hydrodynamic bearing are described together with an analysis model for studying its theoretical performance. The model included an expanded form of the governing Reynolds equation which took account of non-uniform variations in the fluid film thickness. A solution procedure was devised whereby for a given set of adjustment conditions, simultaneously converged fields of fluid film thickness, temperature, viscosity and pressure would result, together with oil film forces. A wide range of operating characteristics were studied with results predicting advantages and benefits over conventional hydrodynamic bearings.

Squeeze-Film Behavior in Porous Circular Disks

1974 ◽  
Vol 96 (2) ◽  
pp. 206-209 ◽  
Author(s):  
P. R. K. Murti
Keyword(s):  
Adverse Effect ◽  
Film Thickness ◽  
Pressure Distribution ◽  
Finite Time ◽  
Reynolds Equation ◽  
Load Capacity ◽  
The Other ◽  
Squeeze Film ◽  
Permeability Parameter ◽  
Circular Disks

The squeeze film behavior between two circular disks is analyzed when one disk has a porous facing and approaches the other disk with uniform velocity. The modified Reynolds equation governs the pressure in the film region while the pressure in the porous facing satisfies the Laplace equation. These equations are solved in a closed form and expressions are derived for pressure distribution, load capacity, and time of approach for the plates in terms of Fourier-Bessel series. It is found that an enhanced value for the permeability parameter diminishes the pressure over the entire disk and also evens out the pressure distribution; however, there is an adverse effect on the load capacity and time of approach. Unlike in the nonporous case, the entire fluid can be squeezed out in a finite time resulting in actual contact of the disks. The porous effects are shown to predominate at very low film thickness values.

Surface Roughness Effects on Fluid Flow between Two Rotating Cylinders

2015 ◽  
Vol 642 ◽  
pp. 275-280
Author(s):  
Sutthinan Srirattayawong ◽  
Shian Gao
Keyword(s):  
Surface Roughness ◽  
Film Thickness ◽  
Reynolds Equation ◽  
Surface Profile ◽  
Fluid Film ◽  
Real Surface ◽  
Contact Center ◽  
Roughness Effects ◽  
Fluid Film Thickness ◽  
Lubricant Viscosity

In general, the thin fluid film problems are explained by the classical Reynolds equation, but this approach has some limitations. To overcome them, the method of Computational Fluid Dynamics (CFD) is used in this study, as an alternative to solving the Reynolds equation. The characteristics of the two cylinders contact with real surface roughness are investigated. The CFD model has been used to simulate the behavior of the fluid flows at the conjunction between two different radius cylinders. The non-Newtonian fluid is employed to calculate the lubricant viscosity, and the thermal effect is also considered in the evaluation of the lubricant properties. The pressure distributions, the fluid film thickness and the temperature distributions are investigated. The obtained results show clearly the significance of the surface roughness on the lubricant flow at the contact center area. The fluctuated flow also affects the pressure distribution, the temperature and the lubricant viscosity in a similar pattern to the rough surface profile. The surface roughness effect will decrease when the film thickness is increased.

An Analysis of the Squeeze Film Between Porous Rectangular Plates

1972 ◽  
Vol 94 (1) ◽  
pp. 64-68 ◽  
Author(s):  
Hai Wu
Keyword(s):  
Film Thickness ◽  
Pressure Distribution ◽  
Laplace Equation ◽  
Carrying Capacity ◽  
Reynolds Equation ◽  
Squeeze Film ◽  
Load Carrying Capacity ◽  
Rectangular Plates ◽  
Load Carrying ◽  
In Series

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.

Dynamic lubrication analysis for a spherical pump

2018 ◽  
Vol 233 (1) ◽  
pp. 18-29 ◽  
Author(s):  
Dong Guan ◽  
Li Jing ◽  
Harry H Hilton ◽  
Junjie Gong
Keyword(s):  
Surface Roughness ◽  
Film Thickness ◽  
Applied Load ◽  
Sine Wave ◽  
Fluid Film ◽  
Radial Clearance ◽  
Wave Loads ◽  
Lubrication Performance ◽  
Fluid Film Thickness ◽  
Lubricant Viscosity

Dynamic lubrication analyses for a spherical pump, consisting of a piston and cylinder, are presented. Contact forces between piston and cylinder are modeled first using an equivalent ball-on-plane model. Both the effects of external loads and operating conditions are considered in a dynamic elastohydrodynamic lubrication model, which is derived from Reynolds equation. Two assumed time-dependent sine-wave and square-wave loads are applied to the model. Fluid film thicknesses are estimated using the model and assumed loads, effects of different structural, and operational parameters, such as piston diameter, radial clearance, applied load, piston speed, lubricant viscosity, and surface roughness, on fluid film thickness are investigated. Fluid film thickness reactions of more realistic smooth and continuous sine wave loads are compared to discontinuous ones in order to verify whether or not assumed ideal loads are acceptable and reliable. Results indicate that piston diameter, speed, lubricant viscosity have positive relations on the dynamic lubrication performance, and increasing these values can improve the dynamic lubrication regime. While the parameters such as radial clearance, applied load, and surface roughness have the verse effects. Furthermore, the impacts of all the above parameters on fluid film are different either. These obtained results can be used to effectively optimize spherical pump lubrication performance.

scholarly journals Coupled effects of applied load and surface structure on the viscous forces during peeling

Soft Matter ◽  
2015 ◽  
Vol 11 (10) ◽  
pp. 1901-1910 ◽  
Author(s):  
Charles Dhong ◽  
Joëlle Fréchette
Keyword(s):  
Film Thickness ◽  
Surface Structure ◽  
Applied Load ◽  
Fluid Film ◽  
Viscous Forces ◽  
Fluid Film Thickness

Surface structure only change the peeling force if the fluid film thickness is sufficiently small.

Conditions of Lift-Off and Film Thickness in Squeeze Film Levitation

2018 ◽  
Vol 140 (3) ◽  
Author(s):  
Noël Brunetière ◽  
Antoinette Blouin ◽  
Guytri Kastane
Keyword(s):  
Film Thickness ◽  
Reynolds Equation ◽  
Operating Conditions ◽  
Experimental Results ◽  
Squeeze Film ◽  
Piezo Actuator ◽  
Dimensionless Analysis ◽  
Displacement Sensors ◽  
Lift Off ◽  
Average Film Thickness

An experimental test rig has been used to analyze the lift-off condition of a squeeze film thrust bearing. It is composed of a vibrating flat plate linked to a piezo-actuator, a cylindrical mass, and two displacement sensors. The frequency and magnitude of oscillation are varied as well as the mass of the solid, to identify the lift-off conditions. The experimental results are compared to numerical simulations. The model solves the transient compressible Reynolds equation coupled with Newton's law for the levitated mass. The model is then used to extend the experimental results to other operating conditions. A dimensionless analysis of the results is performed to study the lift-off conditions and the average film thickness during levitation.

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