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Showing 1 to 17 of 17 for “"Reynolds Equation"”.
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Compressible Lubrication Theory in Pressurized Gases
… studies of lubrication is due to Osborne Reynolds in 1886 who recorded what is now regarded as the canonical equation governing all lubrication problems; this equation and its extensions have become known as the Reynolds equation. In the past century, Reynolds equation has been extended to …
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Surface textures and non-Newtonian fluids for decreased friction in full film lubrication
… are caused by viscous effects for gap based Reynolds Number up to 1.21. The experimental results with Newtonian fluids suggest that there is an optimal surface texture configuration for decreasing friction. In order to determine the optimal texture configuration, numerical methods must be …
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Co-design of surface textures and non-newtonian fluids for decreased friction
… polymer molecular weight), and 3)~the governing equations are computationally expensive to solve. This can significantly limit the design space for optimization; multiple material classes exhibit non-linear rheological behavior, and selecting a given class should be dictated by the optimization, …
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Fluid mechanics of lubricant transport in non-contact regions in the piston ring pack in internal combustion engines
… the region near a piston third land. While the Reynolds equation has been widely employed to model the contact interfaces, more general fluid mechanics has to be applied in the non-contact regions. This thesis is the first work to comprehensively apply Computational Fluid Dynamics (CFD) and …
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Transient Analysis of Isothermal Elastohydrodynamic Point Contacts
… on film thickness and pressure distribution. The Reynolds equation has been derived and extended to accommodate combined rolling and normal approach of contacting bodies. An initial approach to the solution of the problem has been based upon quasi-static solutions, where a constant squeeze film …
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Modeling and Simulation of Microelectromechanical Systems in Multi-Physics Fields
… The new approach utilizes the compressible Reynolds equation coupled with the equation governing the plate deflection. The model accounts for the slip condition of the flow at very low pressures. Perturbation methods are used to derive an analytical expression for the pressure distribution …
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Lubrication in the ball and socket joint of a swash plate mechanism
… assumed to be smooth surfaces. Starting with Reynolds' equation in spherical coordinates, the pressure was solved for and integrated over the surface area of the socket to calculate the force exerted on the rod. This force was matched to the input load force by adjusting the ball-socket …
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Numerical modeling of piston secondary motion and skirt lubrication in internal combustion engines
… with results obtained using an Average Reynolds equation with flow factors. The lubrication model was incorporated into the piston dynamics model, enabling more accurate evaluation of friction and oil transport. Comparison between the dry and lubricated model results demonstrate the …
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Low order models for hybrid gas bearings
… from an assumed stable operating point. The equations include stiffness coefficients taken from a numerical simulation of the compressible Reynolds equation, and damping coefficients taken from a short width Full-Sommerfeld solution. The equations of motion are then modified, and rewritten in …
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Development of a numerical model of piston secondary motion for internal combustion engines
… rigid bodies, and formulating and solving the equations of motion for each body. The hydrodynamic skirt-liner interaction force is computed by solving the Reynolds equation for the oil film and integrating the computed pressure. This essentially one dimensional calculation is performed at …
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An investigation into fluid film lubrication in dynamically loaded bearings
… made. Computer programs based on the classical Reynolds equation and the improved method of solution were developed for the analysis of circuTiferentially grooved, finite journal bearings operating under steady-state and dynamic loading conditions. The improved method of solution produced more …
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Modeling Bubble Coarsening in Froth Phase from First Principles
… which the film thickness reaches Hcr, using the Reynolds equation. Assuming that the number of bubbles decrease exponentially with froth height, and knowing that bubbles coalesce when film drains to a thickness Hcr, a bubble coarsening model has been developed. The model predictions are in …
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Numerical Simulation of Contacts Working Under Mixed Lubricating Conditions
… or the tribofilms forming between asperities The Reynolds equation (RE) is the fundamental equation used to model fluid film lubrication. However, in the ML regime, where both BL and HL coexist, the accurate definition of boundary condition (BC) becomes challenging. The problem of simulating ML …
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Molecular dynamics-based approaches for mesoscale lubrication
… we present a methodology for deriving a modified Reynolds equation (referred to as the Molecular Dynamics-based Equation for Lubrication, or the MODEL) which overcomes these limitations by introducing a Molecular Dynamics-based constitutive relationship for the flow rate through the lubrication …
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Static, dynamic and levitation characteristics of squeeze film air journal bearing: Designing, modelling, simulation and fluid solid interaction
Bearings today need to be able to run at very high speed, providing high positional accuracy for the structure that it supports, and requiring very little or no maintenance. For this to happen, bearings must have tight tolerances and very low or zero friction during operation. This pushes many …
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Experimental and Modelign of Foam Physics in Porous Media
… at the plateau borders is modeled using the Reynolds equation for film thinning and lamella rupture is assumed to occur when the film thickness falls below a certain critical thickness at which the maximum disjoining pressure is attained. This mechanism is incorporated in the pore network …
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NUMERICAL INVESTIGATION OF THE PERFORMANCE OF FLUID FILM JOURNAL BEARINGS
This dissertation numerically investigates the performances of both plain journal bearings and herringbone groove journal bearings, with special attention to the latter. The attitude angle, load capacity, stiffness coefficients and damping coefficients are computed. The effects of groove number, …