All a b c d e f g h i j k l m n o p q r s t u v w x y z Other

Previous Page 7 Next

Displaying 121 – 140 of 357

Showing per page

Guaranteed and robust a posteriori error estimates for singularly perturbed reaction–diffusion problems

Ibrahim Cheddadi, Radek Fučík, Mariana I. Prieto, Martin Vohralík (2009)

ESAIM: Mathematical Modelling and Numerical Analysis

We derive a posteriori error estimates for singularly perturbed reaction–diffusion problems which yield a guaranteed upper bound on the discretization error and are fully and easily computable. Moreover, they are also locally efficient and robust in the sense that they represent local lower bounds for the actual error, up to a generic constant independent in particular of the reaction coefficient. We present our results in the framework of the vertex-centered finite volume method but their nature...

Homogenization of a dual-permeability problem in two-component media with imperfect contact

Abdelhamid Ainouz (2015)

Applications of Mathematics

In this paper, we study the macroscopic modeling of a steady fluid flow in an ε -periodic medium consisting of two interacting systems: fissures and blocks, with permeabilities of different order of magnitude and with the presence of flow barrier formulation at the interfacial contact. The homogenization procedure is performed by means of the two-scale convergence technique and it is shown that the macroscopic model is a one-pressure field model in a one-phase flow homogenized medium.

Homogenization of a one-dimensional model for compressible miscible flow in porous media

Catherine Choquet (2003)

Bollettino dell'Unione Matematica Italiana

We discuss the homogenization of a one-dimensional model problem describing the motion of a compressible miscible flow in porous media. The flow is governed by a nonlinear system of parabolic type coupling the pressure and the concentration. Using the technique of renormalized solutions for parabolic equations and a compensated compactness argument, we prove the stability of the homogenization process.

Homogenization of a three-phase composites of double-porosity type

Ahmed Boughammoura, Yousra Braham (2021)

Czechoslovak Mathematical Journal

In this work we consider a diffusion problem in a periodic composite having three phases: matrix, fibers and interphase. The heat conductivities of the medium vary periodically with a period of size ε β ( ε > 0 and β > 0 ) in the transverse directions of the fibers. In addition, we assume that the conductivity of the interphase material and the anisotropy contrast of the material in the fibers are of the same order ε 2 (the so-called double-porosity type scaling) while the matrix material has a conductivity of...

Homogenization of the compressible Navier–Stokes equations in a porous medium

Nader Masmoudi (2002)

ESAIM: Control, Optimisation and Calculus of Variations

We study the homogenization of the compressible Navier–Stokes system in a periodic porous medium (of period ε ) with Dirichlet boundary conditions. At the limit, we recover different systems depending on the scaling we take. In particular, we rigorously derive the so-called “porous medium equation”.

Homogenization of the compressible Navier–Stokes equations in a porous medium

Nader Masmoudi (2010)

ESAIM: Control, Optimisation and Calculus of Variations

We study the homogenization of the compressible Navier–Stokes system in a periodic porous medium (of period ε) with Dirichlet boundary conditions. At the limit, we recover different systems depending on the scaling we take. In particular, we rigorously derive the so-called “porous medium equation”.

Influence of Vibrations on Convective Instability of Reaction Fronts in Liquids

K. Allali, F. Bikany, A. Taik, V. Volpert (2010)

Mathematical Modelling of Natural Phenomena

Propagation of polymerization fronts with liquid monomer and liquid polymer is considered and the influence of vibrations on critical conditions of convective instability is studied. The model includes the heat equation, the equation for the concentration and the Navier-Stokes equations considered under the Boussinesq approximation. Linear stability analysis of the problem is fulfilled, and the convective instability boundary is found depending on...

Influence of Vibrations on Convective Instability of Reaction Fronts in Porous Media

H. Aatif, K. Allali, K. El Karouni (2010)

Mathematical Modelling of Natural Phenomena

The aim of this paper is to study the effect of vibrations on convective instability of reaction fronts in porous media. The model contains reaction-diffusion equations coupled with the Darcy equation. Linear stability analysis is carried out and the convective instability boundary is found. The results are compared with direct numerical simulations.

Currently displaying 121 – 140 of 357