Characteristics of an Oil Squeeze Film

1982 ◽  
Vol 104 (4) ◽  
pp. 497-502 ◽  
Author(s):  
D. W. Parkins ◽  
W. T. Stanley
Keyword(s):  
Steady State ◽  
Film Thickness ◽  
Squeeze Film ◽  
Normal Velocity ◽  
Oil Film ◽  
Pressure Fields ◽  
Time Histories ◽  
The Mean ◽  
Oscillatory Cycle ◽  
Phase Differences

This paper presents both theoretically and experimentally determined characteristics of an oil squeeze film. In the experimental arrangement, an oil film was contained within two plane surfaces having only normal oscillatory relative motion. The effects of initial oil film thickness, peak to peak amplitude, and frequency of oscillation were measured. A finite difference treatment gave theoretical oil pressure fields and forces for any specified normal velocity. Comparisons were made between the pressure measured at one position and its theoretical counterpart over an oscillatory cycle. Subzero oil film pressures were measured. A steady state (in addition to the dynamic) oil film force was identified, whose magnitude and direction depend on the mean oil film thickness, oscillatory amplitude, and frequency. A region of unstable behavior was found. Theory agreed reasonably with practice, but over estimated some oil film pressures and gave time histories which exhibited phase differences with the measured counterpart. These differences were not explained by including the measured pad misalignment in the theoretical model. Further extensions to the theory are suggested.

Cavitation in an Oscillatory Oil Squeeze Film

1984 ◽  
Vol 106 (3) ◽  
pp. 360-365 ◽  
Author(s):  
D. W. Parkins ◽  
R. May-Miller
Keyword(s):  
Cavitation Bubble ◽  
Lower Surface ◽  
Squeeze Film ◽  
Film Pressure ◽  
Oil Film ◽  
Experimental Apparatus ◽  
Time Histories ◽  
Time Cycle ◽  
Oscillatory Cycle ◽  
Oil Film Pressure

This paper records observed features of cavitation arising in an oscillatory oil squeeze film. In the experimental apparatus, two nondeformable surfaces contained the oil film. The square upper surface oscillated, normally to the oil film, at any frequency between 5 and 50 Hz. A transparent lower surface together with a viewing and synchronising system enabled cavitation bubble patterns in the oil film to be observed and photographed at any point in the oscillatory cycle. Three different behavioral regimes (designated 1, 2, and 3) have been observed, each characterized by the method of forming cavitation bubbles together with particular features in the oil film pressure, thickness and bubble extent-time cycle. Descriptions are given of the salient features of each regime, and the transition from one to another. The paper contains photographs of cavitation bubble patterns at important points in the typical oscillatory cycles together with their location in the oil film pressure and thickness time histories.

Behavior of an Oscillating Oil Squeeze Film

1986 ◽  
Vol 108 (4) ◽  
pp. 639-644 ◽  
Author(s):  
D. W. Parkins ◽  
J. H. Woollam
Keyword(s):  
Film Thickness ◽  
Lower Surface ◽  
Squeeze Film ◽  
Oil Film ◽  
Pressure Transducers ◽  
Experimental Apparatus ◽  
Computer Controlled ◽  
Oscillatory Cycle ◽  
Steady Force ◽  
Oil Film Pressure

This paper records observations of the behavior of an oil film subject to an oscillatory squeeze motion of its containing surfaces. In the experimental apparatus, the square upper surface oscillated at a frequency within the range 5–45 Hz and contained two pressure transducers. A fixed transparent lower surface facilitated viewing of cavitation patterns and their position relative to the pressure transducers. A computer controlled technique enabled these patterns to be photographed at any selected point in the oscillatory cycle, and synchronized with the corresponding instantaneous oil film pressure and thickness. The effect is given of vibratory amplitude, frequency and initial oil film thickness upon the steady force generated by the oscillatory squeeze motion. A previously identified cavitation regime has been shown to be more complex than hitherto supposed. Four sub-regimes have been tentatively identified. Their characteristics are described, together with photographs of typical sequences of cavitation patterns in each subregime, at identified times in the pressure and film thickness cycle. The effects of surrounding oil depth upon the vibratory amplitude at which cavitation first appears, is described. Descriptions are given of the sub-regime appearing at onset, and any changes thereto appearing with further increases in vibratory amplitude.

scholarly journals Inversion of the Thickness of Crude Oil Film Based on an OG-CNN Model

2020 ◽  
Vol 8 (9) ◽  
pp. 653 ◽  
Author(s):  
Zongchen Jiang ◽  
Yi Ma ◽  
Junfang Yang
Keyword(s):  
Neural Network ◽  
Film Thickness ◽  
Spectral Feature ◽  
Coefficient Of Determination ◽  
Mean Deviation ◽  
Oil Film ◽  
Remote Sensing Technology ◽  
Sensing Technology ◽  
The Mean ◽  
Oil Thickness

In recent years, marine oil spill accidents have occurred frequently, seriously endangering marine ecological security. It is highly important to protect the marine ecological environment by carrying out research on the estimation of sea oil spills based on remote sensing technology. In this paper, we combine deep learning with remote sensing technology and propose an oil thickness inversion generative adversarial and convolutional neural network (OG-CNN) model for oil spill emergency monitoring. The model consists of a self-expanding module for the oil film spectral feature data and an oil film thickness inversion module. The feature data self-expanding module can automatically select spectral feature intervals with good spectral separability based on the measured spectral data and then expand the number of samples using a generative adversarial network (GAN) to enhance the generalization of the model. The oil film thickness inversion module is based on a one-dimensional convolutional neural network (1D-CNN). It extracts the characteristics of the spectral feature data of oil film with different thicknesses, and then accurately inverts the oil film’s absolute thickness. In this study, emulsification was not a factor considered, the results show that the absolute oil thickness inversion accuracy of the OG-CNN model proposed in this paper can reach 98.12%, the coefficient of determination can reach 0.987, and the mean deviation remains within ±0.06% under controlled experimental conditions. In the model stability test, the model maintains relatively stable inversion results under the interference of random Gaussian noise. The accuracy of the oil film thickness inversion result remains above 96%, the coefficient of determination can reach 0.973, and the mean deviation is controlled within ±0.6%, which indicates excellent robustness.

Analysis of Oil Film Thickness on a Piston Ring of Diesel Engine: Effect of Oil Film Temperature

2001 ◽  
Author(s):  
Yasuo Harigaya ◽  
Michiyoshi Suzuki ◽  
Masaaki Takiguchi
Keyword(s):  
Diesel Engine ◽  
Temperature Distribution ◽  
Heat Flow ◽  
Film Thickness ◽  
Piston Ring ◽  
Reynolds Equation ◽  
Energy Equation ◽  
Two Dimensional ◽  
Oil Film ◽  
The Mean

Abstract This paper describes that an analysis of oil film thickness on a piston ring of diesel engine. The oil film thickness has been performed by using Reynolds equation and unsteady, two-dimensional (2-D) energy equation with a heat generated from viscous dissipation. The temperature distribution in the oil film is calculated by using the energy equation and the mean oil film temperature is computed. Then the viscosity of oil film is estimated by using the mean oil film temperature. The effect of oil film temperature on the oil film thickness of a piston ring was examined. This model has been verified with published experimental results. Moreover, the heat flow at ring and liner surfaces was examined. As a result, the oil film thickness could be calculated by using the viscosity estimated from the mean oil film temperature and the calculated value is agreement with the measured values.

Elastic Connecting-Rod Bearing With Piezoviscous Lubricant: Analysis of the Steady-State Characteristics

1979 ◽  
Vol 101 (2) ◽  
pp. 190-197 ◽  
Author(s):  
B. Fantino ◽  
J. Frene ◽  
J. Du Parquet
Keyword(s):  
Steady State ◽  
Film Thickness ◽  
Plane Elasticity ◽  
Operating Conditions ◽  
Maximum Pressure ◽  
Connecting Rod ◽  
Oil Film ◽  
Lubricant Analysis ◽  
Relative Eccentricity ◽  
Dimensional Equation

The effect of the deformation of an automotive connecting-rod on the oil film characteristics are studied. The simultaneous elastic deformation and pressure distribution are obtained by iterative methods in steady-state conditions under realistic speeds and loads (5500 rpm, 25,000 N). Plane elasticity relations are used in this study. The following parameters are investigated: —bearing characteristics: bearing thickness B and bearing clearance C, —operating conditions: journal speed N and applied load W, —lubricant: viscosity μ0 and piezoviscous coefficient α. As a result of the deformation, the maximum pressure and the attitude angle are decreased and the relative eccentricity is greatly increased. The minimum oil film thickness is slightly but systematically decreased. The piezoviscosity effect is noticeable only at high loads: it increases slightly the oil film thickness and the maximum pressure. An empirical dimensional equation for the minimum oil film thickness hm is derived numerically for the bearing considered. Thus: hm∼μ0NW0.5(1+0.06108α)B0.12C0.09

Steady State Performance Characteristics of a Tilting Pad Thrust Bearing

2000 ◽  
Vol 123 (3) ◽  
pp. 608-615 ◽  
Author(s):  
Sergei B. Glavatskikh
Keyword(s):  
Steady State ◽  
Film Thickness ◽  
Thrust Bearing ◽  
Operating Conditions ◽  
Performance Characteristics ◽  
Shaft Speed ◽  
Oil Film ◽  
Tilting Pad ◽  
Bearing Load ◽  
Steady State Performance

The paper reports results of the experimental investigation into the steady state performance characteristics of a tilting pad thrust bearing typical of design in general use. Simultaneous measurements are taken of the pad and collar temperatures, the pressure distributions, oil film thickness, and power loss as a function of shaft speed, bearing load, and supplied oil temperature. The effect of operating conditions on bearing performance is discussed. A small radial temperature variation is observed in the collar. A reduction in minimum oil film thickness with load is approximately proportional to p−0.6, where p is an average bearing pressure. It has also been found that the oil film pressure profiles change not only due to the average bearing load but also with an increase in shaft speed and temperature of the supplied oil.

Analysis of Oil Film Thickness and Heat Transfer on a Piston Ring of a Diesel Engine: Effect of Lubricant Viscosity

2004 ◽  
Vol 128 (3) ◽  
pp. 685-693 ◽  
Author(s):  
Yasuo Harigaya ◽  
Michiyoshi Suzuki ◽  
Fujio Toda ◽  
Masaaki Takiguchi
Keyword(s):  
Heat Transfer ◽  
Diesel Engine ◽  
Shear Rate ◽  
Film Thickness ◽  
Piston Ring ◽  
Unsteady State ◽  
Oil Film ◽  
The Mean ◽  
Lubricant Viscosity ◽  
Load Conditions

The effect of lubricant viscosity on the temperature and thickness of oil film on a piston ring in a diesel engine was analyzed by using unsteady state thermohydrodynamic lubrication analysis, i.e., Reynolds equation and an unsteady state two-dimensional energy equation with heat generated from viscous dissipation. The oil film viscosity was then estimated by using the mean oil film temperature and the shear rate for multigrade oils. Since the viscosity for multigrade oils is affected by both the oil film temperature and shear rate, the viscosity becomes lower as the shear rate between the ring and liner becomes higher. Under low load conditions, the viscosity decreases due to temperature rise and shear rate, while under higher load conditions, the decrease in viscosity, is attributed only to the shear rate. The oil film thickness between the ring and liner decreases with a decrease of the oil viscosity. The oil film thickness calculated by using the viscosity estimated by both the shear rate and the oil film temperature gave the smallest values. For multigrade oils, the viscosity estimation method using both the mean oil film temperature and shear rate is the most suitable one to predict the oil film thickness. Moreover, the heat transfer at ring and liner surfaces was examined.

scholarly journals Hydrodynamic Lubrication of Rigid Nonconformal Contacts in Combined Rolling and Normal Motion

1985 ◽  
Vol 107 (1) ◽  
pp. 97-103 ◽  
Author(s):  
M. K. Ghosh ◽  
J. Hamrock ◽  
D. Brewe
Keyword(s):  
Steady State ◽  
Film Thickness ◽  
Carrying Capacity ◽  
Hydrodynamic Lubrication ◽  
Normal Velocity ◽  
Load Carrying Capacity ◽  
Velocity Parameter ◽  
Load Carrying ◽  
Geometry Parameter ◽  
Net Load

A numerical solution to the problem of hydrodynamic lubrication of rigid point contacts with an isoviscous, incompressible lubricant has been obtained. The hydrodynamic load-carrying capacity under unsteady (or dynamic) conditions arising from the combined effects of squeeze motion superposed upon the entraining motion has been determined for both normal approach and separation. Superposed normal motion considerably increases net load-carrying capacity during normal approach and substantially reduces net load-carrying capacity during separation. Geometry has also been found to have a significant influence on the dynamic load-carrying capacity. The ratio of dynamic to steady state load-carrying capacity increases with increasing geometry parameter for normal approach and decreases during separation. The cavitation (film rupture) boundary is also influenced significantly by the normal motion, moving downstream during approach and upstream during separation. For sufficiently high normal separation velocity the rupture boundary may even move upstream of the minimum-film-thickness position. Sixty-three cases were used to derive a functional relationship for the ratio of the dynamic to steady state load-carrying capacity β in terms of the dimensionless normal velocity parameter q (incorporating normal velocity, entraining velocity, and film thickness) and the geometry parameter α. The result is expressed in the form β={α−0.028sech(1.68q)}1/q The ratio of the dynamic to steady state peak pressures in the contact ξ increases considerably with increasing normal velocity parameter during normal approach, with a similar decrease during separation. The ratio is expressed as a function of q and α by ξ={α−0.032sech(2q)}1/q

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