ALE finite element method for simulating flows with the streamfunction-vorticity formulation

Detalhes bibliográficos
Ano de defesa: 2020
Autor(a) principal: Cunha, Luís Henrique Carnevale da
Orientador(a): Não Informado pela instituição
Banca de defesa: Não Informado pela instituição
Tipo de documento: Dissertação
Tipo de acesso: Acesso aberto
Idioma: eng
Instituição de defesa: Universidade do Estado do Rio de Janeiro
Centro de Tecnologia e Ciências::Faculdade de Engenharia
Brasil
UERJ
Programa de Pós-Graduação em Engenharia Mecânica
Programa de Pós-Graduação: Não Informado pela instituição
Departamento: Não Informado pela instituição
País: Não Informado pela instituição
Palavras-chave em Português:
Link de acesso: http://www.bdtd.uerj.br/handle/1/17277
Resumo: Fluid Dynamics is an important area of research in many fields of science and engineering. It is present in the study of aerodynamics, heat exchanges, meteorology and even in biological systems. Due to the complex behavior of flow in different circumstances, being able to accurately describe the fluid motion is a challenge. The purpose of this dissertation is to implement a Finite Element algorithm capable of simulating one phase two-dimensional flow using movable computational mesh grids. The mathematical model of fluid flow used is the stream function-vorticity formulation which is a substitute for the Navier-Stokes equation and is written for the Arbitrary Lagrangian-Eulerian referential to accommodate the mesh movement. A first order semi-Lagrangian method is used to approximate the advective term found in the formulation. This is an unconditionally stable method which allows the algorithm to take larger time steps. A third party open source software called GMSH is used to generate the computational mesh with linear triangular elements. To avoid large distortions, a Laplacian smoothing technique is implemented to help maintain the mesh quality during its movement. Code development is based on Python script language where highly demanding methods are implemented in its compiling version namely Cython. Several test cases were successfully used as benchmarks to verify and validate the proposed new methodology including the cavity driven and Poiseuille flows. Additionally, the flow past an object was chosen as study case for several interesting geometries including the classical cylinder.