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| Author(s): |
Eudes José Arantes
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São Carlos. |
| Institution: | Universidade de São Paulo (USP). Escola de Engenharia de São Carlos (EESC/SBD) |
| Defense date: | 2007-04-20 |
| Examining board members: |
Rodrigo de Melo Porto;
Marcelo Giulian Marques;
Fernando Eduardo Milioli;
José Junji Ota;
Podalyro Amaral de Souza
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| Advisor: | Rodrigo de Melo Porto |
| Abstract | |
Several experimental studies about stepped spillways flow were carried out by several authors, no ever the use of numeric computation tools is still very scarce. This work study numeric simulation in stepped spillways flow was carried out using a computation fluid dynamic (CFD) software. Several hydraulics conditions from the literature were reproduced through simulations by CFD tools. Those simulation results were compared with experimental results. The characteristics of the flow in stepped spillways were analyzed and compared focusing the following aspects: energy dissipation, velocity distribution, air concentration distribution, pressure profiles in the steps, friction resistance and cavitation. The numerical simulation results had a good approximation to the experimental results. All these analyses could be used to validate the use of the computational fluid dynamic tools, to characterize the flow for a possible improvement proposal of this hydraulic structure. The cavitation problem is the great challenge in thigh velocity flows. One solution to reduce the cavitation in the stepped spillways is the construction of a bottom aerator. A numerical study of a bottom aerator was carried out, focusing out of air concentrations, pressures under jet and velocity profiles. It was studied the discharge of air under the jet. As final result, this work proposes a new geometric configuration for stepped spillways with a bottom aerator. This bottom aerator was suggested to be set in the beginning of the spillway chute in order to reduce cavitation risk or to increase the maximum discharge in spillway. (AU) | |