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| Author(s): |
Gabriela Aparecida dos Reis
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | São Carlos. |
| Institution: | Universidade de São Paulo (USP). Instituto de Ciências Matemáticas e de Computação (ICMC/SB) |
| Defense date: | 2012-04-26 |
| Examining board members: |
José Alberto Cuminato;
Savio Brochini Rodrigues;
Fabrício Simeoni de Sousa
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| Advisor: | José Alberto Cuminato |
| Abstract | |
The simulation of free surfaces flows has gained importance in the recent years due to the many practical applications of this type of flow. Among the many numerical methods available for the simulation of fluid flows, there is GENSMAC, which is a numerical technique to simulate Newtonian flows with free surfaces. The implementation of semi-implicitmethods for the temporal discretization of the Navier-Stokes equations allowed a significant loosening in the time step restriction, reducing considerably the computational cost of the simulation of flows with Re 1. But, even with the semi-implicit methods, the time step cannot increase beyond certain limits, well below the CFL restriction, without causing serious accuracy problems in the numerical results and the consequent appearance of non-physical results. Therefore, even in the semi-implicit formulation, a time step restriction is applied. In this work, we analyse and implement in the FREEFLOW2D system a strategy for adaptive time-stepping in order to ensure stability and precision while using the largest possible time step. The efficiency and robustness of the technique incorporated to the implicit formulation of GENSMAC are demonstrated in the solution of two-dimensional complex problems with free surfaces and low Reynolds numbers, including the swelling of the extrudate and jet flow problems (AU) | |
| FAPESP's process: | 10/03669-0 - Adaptative time-step methods for the simulation of free surface flows |
| Grantee: | Gabriela Aparecida dos Reis |
| Support Opportunities: | Scholarships in Brazil - Master |