Doctoral Thesis
DOI
https://doi.org/10.11606/T.55.2008.tde-04032009-111403
Document
Author
Full name
Kémelli Campanharo Estacio
E-mail
Institute/School/College
Knowledge Area
Date of Defense
Published
São Carlos, 2008
Supervisor
Committee
Mangiavacchi, Norberto (President)
Castelo Filho, Antonio
Ferreira, Valdemir Garcia
Pontes, José da Rocha Miranda
Silva, João Batista Campos
Title in Portuguese
Simulação de escoamento de fluidos em superfícies definidas por pontos não organizados
Keywords in Portuguese
CVFEM
Equação de Hele-haw
Esquema semi-lagrangeano
Fluidos não newtonianos
Front-tracking
SPH
Superfície livre
VOF
Abstract in Portuguese
Title in English
Fluid flow simulation in surfaces defined by non-organized points
Keywords in English
CVFEM
Free surface
Front-tracking
Hele-Shaw equation
Non-Newtonian fluid
Semi-lagrangian
SPH
VOF
Abstract in English
Currently, several plastic products are manufactured by polymer injection, in a process named injection molding: molten material is injected into a thin mold where it cools and solidifies. However, unlike other manufacturing processes, the quality of injection-molded parts depends not only on the material and shape of the part, but also on how the material is processed throughout the molding. For this reason, the use of mathematical modelling and numerical simulations has been increasing in order to assist in the manufacturing process, and it has become an essential tool. Therefore, this Sc.D. project has the purpose of simulating the fluid flow during the filling stage of the injection molding process, using the 21/2-dimensional model, compounded by a two-dimensional equation for the pressure field (also known as Hele-Shaw equation) and a three-dimensional equation for the temperature of the fluid. A simpler two-dimensional model for the temperature field is also derived and presented. This project proposes two novel numerical strategies for the solution of Hele-Shaw equation. The first one is based on an Eulerian formulation of the Smoothed Particle Hydrodynamics method, where the particles used in the discretization do not move along as the simulation evolves, thereby avoing the use of meshes. In the second strategy, local active dual patches are constructed on-the-fly for each active point to form a dynamic virtual mesh of active elements that evolves with the moving interface, then the Control Volume Finite Element Method is applied for the pressure field approximation. A dynamic approach of the semi-Lagrangian scheme is applied to the solution of the two-dimensional temperature equation. The project also assesses three new approaches for the treatment of the free surface of the fluid flow. Two of them are based on the Volume of Fluid technique and one of them is a meshless adaptation of the Front-Tracking method. The non-Newtonian behavior is characterized by a family of generalized viscosity models. Supporting numerical tests and performance studies, which assess the accuracy and the reliability of the proposed methodologies, are conducted