doi:10.3934/dcds.2009.23.281          Full text: (246.8K)

Thomas Y. Hou - Department of Applied and Computational Mathematics, California Institute of Technology, Pasadena, CA 91125, United States (email)

Dong Liang - Department of Mathematics and Statistics, York University, Toronto, ON, M3J 1P3, Canada (email)

Abstract: In this paper, we perform a systematic multiscale analysis for convection dominated transport equations with a weak diffusion and a highly oscillatory velocity field. The paper primarily focuses on upscaling linear transport equations. But we also discuss briefly how to upscale two-phase miscible flows, in which case the concentration equation is coupled to the pressure equation in a nonlinear fashion. For the problem we consider here, the local Peclet number is of order $O(\epsilon^{-m+1})$ with $m \in [2,\infty]$ being any integer, where $\epsilon$ characterizes the small scale in the heterogeneous media. Due to the presence of the nonlocal memory effect, upscaling a convection dominated transport equation is known to be very difficult. One of the key ideas in deriving a well-posed homogenized equation for the convection dominated transport equation is to introduce a projection operator which projects the fluctuation onto a suitable subspace. This projection operator corresponds to averaging along the streamlines of the flow. In the case of linear convection dominated transport equations, we prove the well-posedness of the homogenized equations and establish rigorous error estimates for our multiscale expansion.

Keywords: Multiscale analysis, nonlocal memory effect, error analysis, heterogeneous porous media, two-phase miscible flow
Mathematics Subject Classification: Primary: 65N30, 74Q15; Secondary: 76M50

Received:  February   2008
Revised:   July  2008
Published: September  2008

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