Abstract:
This paper presents a combined approach, including CFD numerical and scale
physical modelling, to address the hydraulic behavior of the spillway of a dam.
The spillway studied is an open channel flow which crosses the right abutment of the
dam, it runs in that part of the hillside and it has three separate spans controlled by
Taintor Gates of 9.5 x 6.8 m. The design flow of the spillway is 1,648.5 m3/s and the
verification flow is 1,885.4 m3/s.
Choosing and setting the spillway different forms, such as feeding, piers, gates
positioning, curve at the beginning of the chute, spans convergence, height of the walls
and bucket type, was performed after analyzing numerous options and through numerical
methods in fluid computational hydraulics. The software used was FLOW 3D, it solves
Navier Stokes equations by finite differences. The different options are now being verified
on a physical scale model in the Laboratório Nacional de Engenharia Civil (LNEC).
The use of numerical methods in fluid computational hydraulics is very useful when used
by the designer in combination with the physical modelling. It allows analysing different
options until getting hydraulically optimal solutions which can be tested in a laboratory.
This method provides undisputed advantages in the technical field as well as on the use of
time and resources.
In this presentation there are a variety of approaches created by fluid computational
hydraulics in relation to the spillway dam. It is analysed the hydraulic behaviour of the
different options and the results of numeric model are compared with the obtained in tests
carried out in the physical scale model.
