Avaliação dos métodos de criação e otimização de malhas tridimensionais aplicadas à simulação de placas de orifício

Abstract

Computational Fluid Dynamics is a tool that uses conservation equations to perform numerical simulations of fluid flow. In order to reduce numerical discretization errors, it is necessary to make an appropriate computational mesh in number and configuration of cells, making it possible to achieve effective results. Due to the lack of works about good practices for the construction of computational meshes in the literature, the objective of this research was to analyze the methods offered by the ANSYS package, about mesh generation and optimization for simulations of orifice plate flows. To make this, a geometry was used, based on literature’s studies, to compare experimental and numerical results. The meshes were constructed with the Meshing Workbench software, that uses: Cutcell, Hex dominant, Tetrahedrons, Multizone and Cartesian; and the Meshing Mode Fluent software, that uses the methods: Tetrahedral, Hexcore, Polyhedra e Poly-Hexcore. Simulations were created, analyzing the difference of the pressure’s values between upstream and downstream of the pipe and the Skewness and the Aspect Ratio that characterizes the quality of the mesh. After the best method were obtained, simulations of water’s differents inlet speed conditions were performed in the pipe, enabling you to identify that Poly-Hexcore is the most indicated for orifice plate simulations. Using tools to improve mesh quality, the better ones were: Improve Mesh Quality and Make Polyhedra; which presented an improvement to the mesh in general. Therefore, this work is useful because it will contribute to future research, assisting in the choice of the appropriate mesh for simulations.