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3 produkter
Del 6 - Interdisciplinary Applied Mathematics
Homogenization and Porous Media
Inbunden, Engelska, 1996
1 073 kr
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For several decades developments in porous media have taken place in almost independent areas. In civilengineering, many papers were publisheddealing with the foundations offlow and transport through porous media. The method used in most cases is called averaging, and the notion ofa representative elementary vol- ume(REV)playsanimportantrole. Inchemicalengineering,papersonconceptual models were written on the theory ofmixtures. Intheoretical physics and stochas- tic analysis, percolation theory has emerged, providing probabilistic models for systems where theconnectedness propertiesofsomecomponentdominatethebe- havior. In mathematics, atheoryhasbeendevelopedcalled homogenizationwhich deals with partial differential equations having rapidly oscillating coefficients. Early work in these and related areas was - among others - done by the fol- lowing scientists: Maxwell [Max81] and Rayleigh [Ray92] studied the effective conductivity of media with small concentrations of randomly and periodically, respectively, arranged inclusions. Einstein [Ein06] investigated the effective vis- cosityofsuspensions with hard spherical particles in compressible viscous fluids.Marchenko and Khrouslov [MK64] looked at the asymptotic nature of homog- enization; they introduced a general approach of averaging based on asymptotic tools which can handle a variety ofdifferent physical problems. Unfortunately, up to now, little efforthas been made to bridge the gap between these different fields of research. Consequently, many results were and are dis- covered independently, and scientists are almost unable to understand each other because the respective languages have been developing in different directions.
Flow in Porous Media
Proceedings of the Oberwolfach Conference, June 21–27, 1992
Häftad, Engelska, 2012
1 057 kr
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Jim Douglas, Jr.' These proceedings reflect some of the thoughts expressed at the Oberwolfach Con ference on Porous Media held June 21-27, 1992, organized by Jim Douglas, Jr., Ulrich Hornung, and Cornelius J, van Duijn. Forty-five scientists attended the conference, and about thirty papers were presented. Fourteen manuscripts were submitted for the proceedings and are incorporated in this volume; they cover a number of aspects of flow and transport in porous media. Indeed, there are 223 individual references in the fourteen papers, but fewer than fifteen are cited in more than one paper. The papers appear in alphabetical order (on the basis of the first author). A brief introduction to each paper is given below. Allen and Curran consider a variety of questions related to the simulation of ground water contamination. Accurate water velocities are essential for acceptable results, and the authors apply mixed finite elements to the pressure equation to obtain these ve locities. Since fine grids are required to resolve heterogenei ties, standard iterative procedures are too slow for practical simulation; the authors introduce a parallelizable, multigrid-based it.erative scheme for the lowest order Raviart-Thomas mixed method. Contaminant transport is approximated through a finite element collocation procedure, and an alternating-direction, modified method of characteristics technique is employed to time-step the simulation. Computational experiments carried out on an nCube 2 computer.
Flow in Porous Media
Proceedings of the Oberwolfach Conference, June 21-27, 1992
Inbunden, Engelska, 1993
859 kr
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This volume contains fourteen papers on mathematical problems of flow and transport through porous media presented at the conference held at Oberwolfach, June 21-27, 1992. Among the topics covered are miscible and immiscible displacement, groundwater contamination, reaction-diffusion instabilities and moving boundaries, random and fractal media, microstructure models, homogenization, spatial heterogeneties, inverse problems, degenerate equations. The papers deal with aspects of modelling, mathematical theory, numerical methods and applications in the engineering sciences.