Investigation of aeration in sctructures with stepped spillway

• Grant number: 10/52071-0
• Support Opportunities: Regular Research Grants
• Start date: January 01, 2011
• End date: December 31, 2012
• Field of knowledge: Engineering - Civil Engineering - Hydraulic Engineering
• Principal Investigator: Harry Edmar Schulz
• Grantee: Harry Edmar Schulz
• Host Institution: Escola de Engenharia de São Carlos (EESC). Universidade de São Paulo (USP). São Carlos , SP, Brazil

Abstract

Stepped spillways are extensively used in Hydraulic engineering because they allow simplified projects for dam stability and reduction in the costs and in the size of energy dissipation basin. In the enviromental aspect, the spillways contribute for water quality in dam downstream because it interacts with dissolved oxigen rates. The main hydraulic purpose of steps are energy dissipation, turbulence intensification and earlier the aeration inception point of flow. Therefore, even with earlier inception point achivement (positioned closer to the origin of spillway flow), the areation most of the time, isnt enough to avoid negative pressures on the steps neither cavitation ocurrency. This project conducts the multiphase air-water flow analisys in a way to numerical predict air descharge along the flow, exchange between the twice enviroments. Computational analisys have been performed, in a way to investigate the relation of surface water behave, boundary layer development and position of inception point achivement together, for different shapes of spillway inlet profile (longitudinal background development). The flow simulations are conducted in the Linux enviroment through the use of open software with public domain. In this way the obtained results, when disclosed, may be reproduced without costs by the area especialists that need procedures grounded in safer physical principles. A workstation aquisition will become the development of more complete simulation analisys of these flows available. Relating them with longitudinal background profile on spillway inlet, an aspect that isn’t yet well defined in the literature. (AU)