2022 – Hydraulic Jump Stilling Basin over Rough Beds

Shayan Maleki PhD, Principal Engineer – Dams and Hydropower
Peyman Andaroodi Principal Storage Planning, Seqwater
Virgilio Fiorotto Full Professor, Formerly, University of Trieste, Italy

This paper presents the application of a new approach that is able to define the hydraulic jump peculiarities in regular rough bed conditions. This approach extends the literature and guidelines, such as U.S. Bureau of Reclamation (USBR), on the design of a stilling basin over a rough bed, taking into account both the Froude number and the bottom roughness. The literature formulas consider the effect of the roughness only, neglecting the one due to the incident Froude number in the evaluation of integrated bottom shear stress and therefore, they result in error (±30%) in the evaluation of the hydraulic jump peculiarities.

The presented method is developed using Physical Hydraulic Model (PHM) results related to the measurements of the flow field in the hydraulic jump region. The results of this theoretical method is applied to the design of the stilling basin of a 50m high dam. Computational Fluid Dynamics (CFD) of the dam is used to validate and verify the design undertaken using this theoretical approach. The comparison of the CFD results with the theoretical approach highlights the reliability and accuracy of this method.

The results presented might be useful in the design of hydraulic jump stilling basins over rough beds.