Contact of rough bodies in the presence of a compressible lubricant

1988 ◽  
Vol 24 (12) ◽  
pp. 1217-1225 ◽  
Author(s):  
E. A. Kuznetsov
Keyword(s):  
Compressible Lubricant

Characteristics of a Self-Lubricated Stepped Thrust Pad of Infinite Width With Compressible Lubricant

1959 ◽  
Vol 81 (2) ◽  
pp. 135-145 ◽  
Author(s):  
Kikuo C. Kochi
Keyword(s):  
Optimum Design ◽  
Practical Interest ◽  
Numerical Data ◽  
Numerical Results ◽  
Design Parameters ◽  
Analytic Expressions ◽  
Thrust Pad ◽  
Compressible Lubricant

Harrison’s equation for the pressure in a gas-lubricated bearing of infinite width is solved for a thrust pad with stepped configuration. Analytic expressions for the pressure and load are developed. Numerical results are presented graphically. The analytic expressions together with the numerical data permit most of those characteristics of the stepped pad of practical interest to be completely determinable. Determination of optimum design parameters is given by a pair of graphs.

A Waved Journal Bearing Concept-Evaluating Steady-State and Dynamic Performance With a Potential Active Control Alternative

1993 ◽  
Author(s):  
Florin Dimofte
Keyword(s):  
Steady State ◽  
Wave Amplitude ◽  
Journal Bearing ◽  
Load Capacity ◽  
Dynamic Stiffness ◽  
Dynamic Performance ◽  
Film Stability ◽  
Dynamic Coefficients ◽  
The Waves ◽  
Compressible Lubricant

Abstract Analysis of the waved journal bearing concept featuring a waved inner bearing diameter for use with a compressible lubricant (gas) is presented. The performance of generic waved bearings having either three or four waves is predicted for air lubricated bearings. Steady-state performance is discussed in terms of bearing load capacity, while the dynamic performance is discussed in terms of fluid film stability and dynamic coefficients. It was found that the bearing wave amplitude has an important influence on both steady-state and dynamic performance of the waved journal bearing. For a fixed eccentricity ratio, the bearing steady-state load capacity and direct dynamic stiffness coefficient increase as the wave amplitude increases. Also, the waved bearing becomes more stable as the wave amplitude increases. In addition, increasing the number of waves (e.g., four waves instead of three waves) reduces the waved bearing’s sensitivity to the direction of the applied load relative to the wave. However, the range in which the bearing performance can be varied decreases as the number of waves increases. Therefore, both the number and the amplitude of the waves must be properly selected to optimize the waved bearing design for a specific application. Another possibility is to use the waved bearing to actively control the rotor-bearing system dynamic coefficients via actively controlling the wave amplitude.

Magnetogasdynamic thrust bearing with an axial pinch

1969 ◽  
Vol 38 (4) ◽  
pp. 673-677 ◽  
Author(s):  
G. Ramanaiah
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Thrust Bearing ◽  
Load Capacity ◽  
Axial Current ◽  
Pinch Effect ◽  
Electrically Conducting ◽  
Compressible Lubricant

An analysis of a hydrostatic thrust bearing with electrically conducting compressible lubricant under an axial-current-induced pinch is presented. It is shown that the load capacity of the bearing can be increased by the pinch effect and the magnitude of the pinch effect depends on the mass flow rate. It is also shown that a load proportional to the square of the axial current can be sustained even when there is no flow or external pressurization.

A Theoretical Analysis of a Compliant Shell Air Bearing

1977 ◽  
Vol 99 (1) ◽  
pp. 75-81 ◽  
Author(s):  
Kong Ping Oh ◽  
Steve M. Rohde
Keyword(s):  
Finite Element ◽  
Steady State ◽  
Theoretical Analysis ◽  
Finite Difference Methods ◽  
Approximate Solutions ◽  
Journal Bearings ◽  
Air Bearing ◽  
Difference Methods ◽  
Compressible Lubricant ◽  
Steady State Performance

A mathematical analysis of a class of compliant journal bearings operating with a compressible lubricant is presented. Finite element methods are used to obtain approximate solutions, and results for the rigid case are compared to those obtained by finite difference methods. Results for the case in which the compliant bearing component is a shell show that the steady-state performance can be radically different from that predicted by the rigid bearing assumption. These differences may explain the antiwhirl characteristics exhibited by this type of bearing.

On the Behavior of Grooved Plate Thrust Bearings With Compressible Lubricant

1968 ◽  
Vol 90 (1) ◽  
pp. 226-232 ◽  
Author(s):  
M. Wildmann
Keyword(s):  
Groove Width ◽  
Thrust Bearings ◽  
Usual Assumption ◽  
Compressible Lubricant

The equations for pressure and load for a grooved plate bearing are derived by assuming that the grooves are sinusoidal rather than square. The usual assumption of zero groove width is thus removed. The effects of groove width and lubricant compressibility are examined independently. Finally, limiting solutions for high compressibility numbers are obtained.

Research Note: Performance of an Externally Pressurized Gas Porous Thrust Bearing

1974 ◽  
Vol 16 (5) ◽  
pp. 351-352
Author(s):  
P. R. K. Murti
Keyword(s):  
Pressure Distribution ◽  
Closed Form ◽  
Flow Rate ◽  
Thrust Bearing ◽  
Load Capacity ◽  
Axial Flow ◽  
Static Stiffness ◽  
Thrust Pad ◽  
Bearing Number ◽  
Compressible Lubricant

A circular porous thrust pad, externally pressurized with a compressible lubricant and with predominantly axial flow in the bearing matrix, is analysed. Closed-form expressions are derived for pressure distribution, load capacity, mass flow rate and static stiffness of the bearing. It is concluded that optimum performance of the bearing is obtained when it operates close to the critical bearing number.

A Compressible Thermohydrodynamic Analysis of Journal Bearings Lubricated With Supercritical CO2

2017 ◽  
Author(s):  
Ssu-Ying Chien ◽  
Mark Cramer ◽  
Alexandrina Untaroiu
Keyword(s):  
Reynolds Equation ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Flow Dynamics ◽  
Navier Stokes ◽  
Supercritical Regime ◽  
Effective Bulk Modulus ◽  
Thermodynamic Critical Point ◽  
Temperature Boundary ◽  
Compressible Lubricant

In this study, a compressible thermohydrodynamic (THD) model was developed to examine the flow dynamics of a journal bearing lubricated with supercritical carbon dioxide (sCO2). This model employed a general form of the Reynolds equation governing compressible lubricant flows with a well-known analytical equation of state, and a viscosity model that depends on both pressure and temperature. In order to verify the model, we first compared the results of this compressible Reynolds equation to the full Navier-Stokes solutions. The accuracy of the model was found to be reasonable when the operating condition is sufficiently far from the thermodynamic critical point. Additionally, the numerical solution suggests that different temperature boundary conditions give slight different results due to the small variations of density and temperature across the gap. Finally, the general approach presented in this study introduces a new single parameter — effective bulk modulus that characterize both the frictional and thermodynamic fluid response. The model developed in this study can provide guidance for further studies of CO2-lubricated bearings operating in the full supercritical regime.

scholarly journals Hydrodynamic calculation of wedge-shaped system «slider-guide» operating on compressible lubricant in presence of melt on surface of guide

2021 ◽  
pp. 10-14
Author(s):  
K. S. Akhverdiev ◽  
◽  
E. A. Bolgovа ◽  
E. O. Lagunova ◽  
S. V. Kumanin ◽  
...  
Keyword(s):  
Hydrodynamic Lubrication ◽  
Mechanical Energy ◽  
Extreme Case ◽  
Calculation Model ◽  
Hydrodynamic Calculation ◽  
Self Similar Solution ◽  
Lubrication Mode ◽  
Mechanical Energy Dissipation ◽  
Self Similar ◽  
Compressible Lubricant

In the article on the basis of the equation of motion of the compressible lubricant for the «thin layer», continuity, state, and the equation describing the profile of the molten contour taking into account the formula of mechanical energy dissipation the asymptotic and self-similar solution is found for the extreme (when the speed tends to infinity) and non-extreme case. As a result of solving the problem, a refined mathematical calculation model of a wedgeshaped sliding support with a low-melting metal coating on a movable contact surface is obtained, which compensates for an emergency lack of lubricant and provides a stable hydrodynamic lubrication mode

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