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The Finite Element Method Solution Of Reaction-diffusion-advection Equations In Air Pollution

We consider the reaction-diffusion-advection (RDA) equations resulting in air pollution mod-
eling problems. We employ the finite element method (FEM) for solving the RDA equations
in two dimensions. Linear triangular finite elements are used in the discretization of problem
domains. The instabilities occuring in the solution when the standard Galerkin finite element
method is used, in advection or reaction dominated cases, are eliminated by using an adap-
tive stabilized finite element method. In transient problems the unconditionally stable Crank-
Nicolson scheme is used for the temporal discretization. The stabilization is also applied for
reaction or advection dominant case in the time dependent problems.
It is found that the stabilization in FEM makes it possible to solve RDA problems for very
small diffusivity constants. However, for transient RDA problems, although the stabilization
improves the solution for the case of reaction or advection dominance, it is not that pronounced
as in the steady problems. Numerical results are presented in terms of graphics for some test
steady and unsteady RDA problems. Solution of an air pollution model problem is also provided.

Identiferoai:union.ndltd.org:METU/oai:etd.lib.metu.edu.tr:http://etd.lib.metu.edu.tr/upload/3/12609987/index.pdf
Date01 September 2008
CreatorsTurk, Onder
ContributorsTezer-sezgin, Munevver
PublisherMETU
Source SetsMiddle East Technical Univ.
LanguageEnglish
Detected LanguageEnglish
TypeM.S. Thesis
Formattext/pdf
RightsTo liberate the content for public access

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