The Experts below are selected from a list of 6015 Experts worldwide ranked by ideXlab platform
Cass T Miller - One of the best experts on this subject based on the ideXlab platform.
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computation of the interfacial area for two fluid porous medium systems
Journal of Contaminant Hydrology, 2002Co-Authors: Elisa Dalla, Markus Hilpert, Cass T MillerAbstract:We develop a method to compute interfacial areas from three-dimensional digital representations of multiphase systems. We approximate the interfaces with the isosurface generated by the standard marching-cube algorithm from the discrete phase distribution. We apply this approach to two-fluid pore-scale simulations by (1) simulating a random packing of spheres that obeys the grain-size distribution and porosity of an experimental porous medium system, and (2) using a previously developed pore-morphology-based model in order to predict the phase distribution for a water-wet porous medium that undergoes primary Drainage. The predicted primary Drainage Curve and interfacial areas are in good agreement with the experimental values reported in the literature, where interfacial areas were measured using interfacial tracers. The energy dissipation during Haines jumps is significant: thus, the mechanical work done on the system is not completely converted into surface energy, and interfacial areas may not be deduced from the primary Drainage Curve.
Andreas Mortensen - One of the best experts on this subject based on the ideXlab platform.
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Capillarity in pressure infiltration: improvements in characterization of high-temperature systems
Journal of Materials Science, 2012Co-Authors: Alain Léger, N. R. Calderon, Raphaël Charvet, Willy Dufour, C. Bacciarini, Ludger Weber, Andreas MortensenAbstract:In the pressure infiltration of metal matrix composites, molten metal is injected under external pressure into a porous preform of the reinforcing material. Equilibrium capillary parameters characterizing wetting for this process are summarized in plots of metal saturation versus applied pressure, also known as Drainage Curves. Such Curves can be measured in our laboratory during a single experiment with an infiltration apparatus designed to track the rate of metal penetration into porous preforms under conditions characteristic of metal matrix composite processing (temperatures in excess of 1000 °C and pressures in the order of 10 MPa). For such measurements to be valid, infiltration of the preform with molten metal must be mechanically quasi-static, i.e., the metal must flow at a rate sufficiently low for the metal pressure to be essentially uniform across the preform at all times. We examine this requirement quantitatively, using a finite-difference model that simulates the unsaturated unidirectional ingress of molten metal into a ceramic particle preform of finite width. We furthermore present improvements in the experimental apparatus developed in our laboratory to measure the entire Drainage Curve in a single experiment. We compare numerical results with new experimental data for the copper/alumina system to show (i) that pressurization rates sufficiently low for quasi-static infiltration can be produced with this apparatus, and (ii) that taking the relative permeability equal to the saturation yields better agreement with experiment than does the expression originally proposed by Brooks and Corey.
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infiltration of graphite preforms with al si eutectic alloy and mercury
Scripta Materialia, 2007Co-Authors: J M Molina, E Louis, A Rodriguezguerrero, M Bahraini, L Weber, J Narciso, F Rodriguezreinoso, Andreas MortensenAbstract:Porous isotropic graphite preforms are infiltrated with Al–12 wt.%Si at 680 °C using an applied pressure of between 2 and 8 MPa. Densitometry after infiltration and solidification is then used to deduce the relevant Drainage Curve. For comparison, the same preforms are also characterized by mercury porosimetry. By comparing the Curves obtained from those two measurements using the Brooks–Corey relation, a contact angle of the Al–Si eutectic on graphite of 139° is obtained, in relatively good agreement with literature data.
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wetting in infiltration of alumina particle preforms with molten copper
Journal of Materials Science, 2005Co-Authors: M Bahraini, L Weber, J Narciso, Andreas MortensenAbstract:The high-temperature wettability of alumina particulate preforms by copper is investigated by means of infiltration experiments conducted at 1473 K under low oxygen partial pressure. Wetting is quantified in terms of Drainage Curves, which plot the volume fraction of metal in the porous medium vs. the applied pressure. Mercury porosimetry is also used on similar preforms for comparison. The effect of volume fraction, particle geometry and capillary parameters on the Drainage Curve are studied and compared with the expression proposed by Brooks and Corey. The influence of the particle volume fraction and capillary parameters characterizing wetting in the two systems is discussed to derive an effective contact angle for wetting of alumina particles by molten copper.
Elisa Dalla - One of the best experts on this subject based on the ideXlab platform.
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computation of the interfacial area for two fluid porous medium systems
Journal of Contaminant Hydrology, 2002Co-Authors: Elisa Dalla, Markus Hilpert, Cass T MillerAbstract:We develop a method to compute interfacial areas from three-dimensional digital representations of multiphase systems. We approximate the interfaces with the isosurface generated by the standard marching-cube algorithm from the discrete phase distribution. We apply this approach to two-fluid pore-scale simulations by (1) simulating a random packing of spheres that obeys the grain-size distribution and porosity of an experimental porous medium system, and (2) using a previously developed pore-morphology-based model in order to predict the phase distribution for a water-wet porous medium that undergoes primary Drainage. The predicted primary Drainage Curve and interfacial areas are in good agreement with the experimental values reported in the literature, where interfacial areas were measured using interfacial tracers. The energy dissipation during Haines jumps is significant: thus, the mechanical work done on the system is not completely converted into surface energy, and interfacial areas may not be deduced from the primary Drainage Curve.
Veronique Michaud - One of the best experts on this subject based on the ideXlab platform.
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Dynamic saturation Curve measurement for resin flow in glass fibre reinforcement
Composites Part A: Applied Science and Manufacturing, 2012Co-Authors: Markus Nordlund, Veronique MichaudAbstract:A methodology is presented to determine the saturation Curve of a resin/glass fabric system, during infiltration in a transparent mould under constant flow rate. Video acquisitions are transformed by image analysis into saturation level versus position and time, and coupled to inlet pressure measurements. A numerical multiphase flow model is then used to simulate the infiltration for various combinations of Drainage Curve parameters. The numerical parameters to describe the saturation and relative permeability are determined by response surface optimization. The Drainage Curve and relative permeability equations determined at one time are shown to adequately describe the entire injection process, and to be flow-rate dependent. (C) 2011 Elsevier Ltd. All rights reserved.
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Drainage Curve measurements in dualscale fiber reinforcements
FPCM-9 9th International Conference on Flow Processes in Composite Materials, 2008Co-Authors: Markus Nordlund, Veronique Michaud, J A E MansonAbstract:SUMMARY: A methodology is presented to determine the saturation Curve of a resin/glass fabric system, during infiltration in a transparent mould under constant flow rate. Video acquisitions are transformed by image analysis into saturation level versus position and time, and coupled to inlet pressure measurements. A numerical multiphase flow model is then used to simulate the infiltration for various combinations of Drainage Curve parameters. The numerical parameters to describe the saturation and relative permeability are determined by response surface optimization. The Drainage Curve and relative permeability expression determined at one time are shown to adequately describe the entire injection process.
Markus Hilpert - One of the best experts on this subject based on the ideXlab platform.
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computation of the interfacial area for two fluid porous medium systems
Journal of Contaminant Hydrology, 2002Co-Authors: Elisa Dalla, Markus Hilpert, Cass T MillerAbstract:We develop a method to compute interfacial areas from three-dimensional digital representations of multiphase systems. We approximate the interfaces with the isosurface generated by the standard marching-cube algorithm from the discrete phase distribution. We apply this approach to two-fluid pore-scale simulations by (1) simulating a random packing of spheres that obeys the grain-size distribution and porosity of an experimental porous medium system, and (2) using a previously developed pore-morphology-based model in order to predict the phase distribution for a water-wet porous medium that undergoes primary Drainage. The predicted primary Drainage Curve and interfacial areas are in good agreement with the experimental values reported in the literature, where interfacial areas were measured using interfacial tracers. The energy dissipation during Haines jumps is significant: thus, the mechanical work done on the system is not completely converted into surface energy, and interfacial areas may not be deduced from the primary Drainage Curve.
