Full text
| |
| Author(s): |
Vinicius Malatesta
Total Authors: 1
|
| Document type: | Doctoral Thesis |
| Press: | São Carlos. |
| Institution: | Universidade de São Paulo (USP). Instituto de Ciências Matemáticas e de Computação (ICMC/SB) |
| Defense date: | 2014-07-07 |
| Examining board members: |
Leandro Franco de Souza;
Erick de Moraes Franklin;
Maria Luísa Bambozzi de Oliveira;
Gherhardt Ribatski;
Oscar Mauricio Hernandez Rodriguez
|
| Advisor: | Leandro Franco de Souza |
| Abstract | |
Flows over concave surfaces are subject to centrifugal instability. It gives rise to stramwise vortices known as Görtler vortices. These vortices are responsible for generating strong distortions in the velocity profiles. As the vortices are counterrotating, two regions arise between them: a region of uowash and a region of downwash. In the upwash region, the fluid near the wall is convected away from it. In the downwash region the opposite happens, the fluid moving at a faster speed is moved towards the wall. The vortices initially amplify linearly in the downstream. When their amplitude is already high, in the non-linear development region, a mushroom-type structure, with the velocity distribution in the main flow direction, is formed. This new three-dimensional velocity distribution is different from the boundary layer obtained with the solution of Blasius equations. Taking into account a thermal boundary layer, on average, an increase in the heat transfer in the wall direction has been observed. In the present work, it is verified numerically the heat transfer in the presence of Görtler vortices. A simulation code was developed and implemanted usin Direct Numerical Simulation (DNS). The results of this work show the intensification of heat transfer through the Görtler vortices both in the non-linear regime and in the secondary instability (AU) | |
| FAPESP's process: | 10/00495-1 - Direct Numerical Simulation of flows over concave surfaces with heat transfer |
| Grantee: | Vinicius Malatesta |
| Support Opportunities: | Scholarships in Brazil - Doctorate |