Hydraulic Jump Stilling Basin Design over Rough Beds

Abstract

This paper presents a new method that is able to define the hydraulic jump peculiarities in rough-bed conditions. The findings of this paper improve the literature and guidelines on the design of a stilling basin over a rough bed, taking into account both the Froude number and bottom roughness. It starts with experimental evidence on the flow field and considers the characteristic length scale of the phenomenon as drawn from velocity measurements in the hydraulic jump region. The assumption in the length scale leads to different results compared with the known formulas in the literature related to the hydraulic jump on a rough bed. The formulas in the literature consider the effects of gravel roughness only, neglecting the effects due to the incident Froude number in the evaluation of integrated bottom shear stress. The comparison of the presented results with experimental measurements in the literature highlights the reliability and accuracy of this novel method. This method is theoretically based, but because it needs experimental data in application, it can be considered semiempirical. The results presented here allow for the design of hydraulic jump stilling basins over rough beds.