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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 23 for “"Elastohydrodynamic"”.
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Adjoint Error Estimation for Elastohydrodynamic Lubrication
… estimation techniques are applied to complex elastohydrodynamic lubrication (EHL) problems. A functional is introduced, namely the friction, and justification is provided as to why this quantity, and hence its accuracy, is important. An iterative approach has been taken to develop …
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Adaptive Numerical Methods for Elastohydrodynamic Lubrication
Numerical solutions to elastohydrodynamic lubrication problems have been computed for the last half century. Over the past decade multilevel techniques have been successfully applied in several solvers and significant speed-ups achieved. The aim of numerical research in this field is to develop …
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Transient Analysis of Isothermal Elastohydrodynamic Point Contacts
… is very important to understand the behaviour of elastohydrodynamic films, formed between contacting surfaces in order to improve working performance and to prevent surface failure by wear or fatigue. As applied load, speed and the conjunction geometry vary with time under realistic operating …
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Elastohydrodynamic lubrication of smooth and rough surfaces
Different aspects of Elastohydrodynamic Lubrication (EHL) are studied. For smooth surfaces, a novel approach which solves separately the inlet and outlet regions by using the fracture mechanics equations, is proposed to solve EHL line contacts for shape and pressure. For rough surfaces, the full …
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High Order Finite Element Solution of Elastohydrodynamic Lubrication Problems
… is introduced to solve one- and two-dimensional Elastohydrodynamic Lubrication (EHL) problems (line contact and point contact). This thesis provides an introduction to elastohydrodynamic lubrication, including some history, and a description of the underlying mathematical model which is based …
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Numerical Analysis of Transient, Line-Contact Problems in Elastohydrodynamic Lubrication
Elastohydrodynamic (EHD) lubrication is a lubrication process which usually occurs in concentrated load-supporting or load-transmitting contacts. Such contacts exist, for example, in rolling-element bearings, gears and cam-follower mechanisms. In EHD lubrication, the contact surfaces are not only …
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Development and Application of Elastohydrodynamic Lubrication Model for Piston Pin
The piston pin, as the connection between the piston and the connecting rod, is a crucial component in the internal combustion engine. It transfers the cylinder pressure of combustion to the crankshaft and is subjected to high stress and harsh lubrication conditions. Pin seizure is a severe problem …
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The Effect of Surface Irregularities on The Elastohydrodynamic Lubrication of Sliding Line Contacts
… the effects of surface irregularities on the elastohydrodynamic (EHD) lubrication of sliding line contacts is presented. A series of case studies illustrates the effect of furrow, asperity, and wavy surface irregularities on the pressure distribution, film thickness, and subsurface octahedral …
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Thermal non-Newtonian elastohydrodynamic lubrication of line contacts under sliding-rolling and simple sliding conditions
… Reynolds-Eyring equation is derived to study the elastohydrodynamic lubrication of line contacts. This lubrication condition is usually found in spur gears, roller bearings and cams. The inlet region with back-flow is treated with a control volume scheme to obtain the temperature solution. A …
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The performance of high speed reciprocating polymer seals in water
The elastohydrodynamic lubrication of polymeric piston seals in a water powered rockdrill has been modelled in this thesis. Current seal designs, consist of an Ultra High Molecular Weight Polyethylene (UHMWPE) ring, energised to remain in contact with the reciprocating piston, using a nitrile …
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High pressure carbon-13 NMR studies of dynamics in disordered systems
… first system is 2-ethylhexylbenzoate, a model elastohydrodynamic lubricant. The second system is L-$\alpha$-dipalmitoyl phosphatidylcholine, a model biomembrane system. Also, the design of a data acquisition system specifically targeted at the study of dynamic processes is described along with …
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Low Reynolds number biohybrid swimming
… force on a microscale filament. A slender body elastohydrodynamic model is used to provide design criteria for the system, ensuring that the actuation of a single cell cluster will produce time irreversible deformation and net propulsion at low Reynolds number. Microscale polydimethylsiloxane …
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Chemically driven soft bioinspired systems and the variational formulation of physics-informed neural networks
… within these protocells. Using a continuum elastohydrodynamic theory, we demonstrate how attractive van der Waals interactions between lipid membrane, aqueous solvent, and Aluminum surface lead to the emergence of an elastohydrodynamic instability. This leads to the formation of protocell …
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Numerical modeling of piston secondary motion and skirt lubrication in internal combustion engines
… calculation of approximate piston dynamics. An elastohydrodynamic lubrication model was then developed to allow direct numerical simulation of the effect of piston tooling marks, and comparison with results obtained using an Average Reynolds equation with flow factors. The lubrication model was …
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Drug eluting prosthetic joints through drug cluster morphology control
… which through a combination of weeping and elastohydrodynamic lubrication, reduced the overall wear rate of the UHMWPE. Treatment of Staphylococcus aureus infected lapine knee with the antibiotic eluting UHMWPE showed complete bacterial eradication without any detectable systemic side …
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Biophysics of Helices: Devices, Bacteria and Viruses
… problem, a pertubative, asymptotic, elastohydrodynamic approach is used to characterise the deformation that arises from and in turn affects the motion. This framework is applied to the helical filaments of bacteria and magnetically actuated microswimmers. The dissertation then turns …
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Polymer Nanocomposites: Polymer And Particle Dynamics And Its Application As Lubricant
… into the wear track and extension of the elastohydrodynamic lubrication regime to Sommerfeld numbers more than an order of magnitude larger than for PAO. ii
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