AnÃlise de escoamentos compressÃveis nÃo-viscosos em trÃs dimensÃes utilizando o mÃtodo dos elementos finitos por aresta

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

This work has as its main goal the development of a computational tool for numerical simulation of compressible fluid flow problems for three dimensions, using as starting point the computational tool developed by LYRA (1994) that dealt with fluid flow problems in two dimensional domain. For the development of this tool, a space discretization was adopted using the finite element method with an edge based data structure, and with the domain being discretized by a tetrahedra mesh. The Euler equations represent the phenomena studied in this work. A Galerkin finite element formulation was used and this creates oscillatory solutions and is unstable for hyperbolic problems, as it is based an a centered approach of the convective term. Upwind discretization techniques, originated in the finite difference method and widely used in the finite volume method, it were used for stabilization. The techniques used were a first order Upwind scheme proposed by Roe, and a MUSCL/LE (Monotonic Upstream-centered Schemes will be Conservations Laws -Local Extremum Diminishing) scheme with limiter functions for stabilization of high order and capture of shocks without oscillations. For generation of meshes for the simulations the Gmsh program was used. The C++ language was used to develop a pre-processor, based on a package for meshes management called FMDB (Flexible Distributed Mesh Database) and Matlab or Octave were used for finishing the necessary calculations to be used in the processor. This preprocessor was developed separately of the main program because edge coefficients depend only on the mesh and it is run only once for each mesh. The programming language for the development of the main program was FORTRAN 90, which made possible one better script and modularity when compared with FORTRAN 77. For the visualization of the results Visit and Para-View were used. Finally, some numerical tests were carried through and compared with results found in literature

ASSUNTO(S)

compressive flows escoamentos compressÃveis elementos finitos finite elements dinÃmica dos fluidos computacionais engenharia civil computational fluid dynamic

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