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I. A. Neac{\&}{\#}537;u: 
''Advanced description of the micro-flow in tribo-systems involving porous media''; 
Supervisor, Reviewer: B. Scheichl, H. P. Evans, A. Kluwick; Institute of Fluid Mechanics and Heat Transfer, 2017; oral examination: 2017-06-29.

@phdthesis{neacșu17[TUW-189391],
    author = {Neac{\&}{\#}537;u, Ioana Adina},
    title = {Advanced description of the micro-flow in tribo-systems involving porous media},
    school = {Institute of Fluid Mechanics and Heat Transfer},
    year = {2017},
    url = {http://publik.tuwien.ac.at/files/publik_189391.pdf},
    keywords = {cavitation, hydrodynamic lubrication, journal bearing, porous liner, recondensation, seepage flow, tribology},
    abstract = {\par
 A new and comprehensive approach for describing, amongst others, cavitation in porous journal bearings operating under the regime of hydrodynamic lubrication is presented. The mass-conservative model couples the Reynolds equation for the fluid film with the Darcy's law for flow through porous media. The resulting system of equations is discretized using finite differences and solved iteratively by introducing an advantageous artificial pressure-density relation. \par
 An extensive numerical analysis where the governing parameters are varied along a wide range of values is carried out. It is found that at the point of film reformation the fluid saturation will exhibit a discontinuity, which does not depend on the applied load. In order to determine the limits of applicability of this approach, specific investigations aim at evaluating the extreme cases of relatively low and high bearing loads and very long/short as well as highly porous/(almost) massive bearings. Converged solutions areobtained for values of the eccentricity ratio of up to 0.9, and, interestingly, for the case of a very permeable seat the friction coefficient is seen to increase around this value, in contrast with the otherwise seen decreasing trend. Finally, the results obtained by simulations are compared with measurements performed on real-life bearings. This was achieved by an accurate interpolation scheme, which was able to predict the eccentricity ratio corresponding to the experimentally imposed load. The numerically calculated values of the friction coefficient are found to reproduce the experimentally obtained ones satisfactorily well in terms of overall trends, yet the former lie predominantly below the measured ones. \par
}
}