Converging stepped spillway flow

ABSTRACT

Wall deflection in supercritical flow induces standing waves which significantly influence the flow field close to the wall. This paper analyses the flow in the converging stepped spillway, using two scale-models with different step heights and convergence angles. Results show that the height and the width of the standing wave increase with the increase of the convergence angle. Air concentration decreases while the air–water mixture velocity and residual energy head increase in the vicinity of the converging wall and gradually attain the values for the undisturbed flow outside the standing wave. Compared to the prismatic chutes of equal upstream width, converging spillways are less efficient energy dissipators. Equations for predicting the maximum flow depth and the width-averaged residual energy are proposed.

Keywords:

• Converging walls
• residual energy
• scale-model
• standing wave
• stepped spillway

Acknowledgements

The authors acknowledge the support of the Institute for the Development of Water Resources “Jaroslav Cerni” by providing the facilities to conduct the research presented in this paper.

ORCiD

Budo Zindovic http://orcid.org/0000-0002-3309-2787

Additional information

Funding

This work was supported by the Ministry of Education, Science and Technological Development of Serbia [grant numbers TR37005, TR37009, TR37010 and TR37014].