Influence of channel width and tailwater depth on local scour caused by square jets

Abstract

This present study deals with the local scour caused by submerged square jets carried out to understand the influence of channel expansion ratio (ratio of channel width-to-nozzle size) at various tailwater depths. Results show that the expansion ratio can be important and needs to be incorporated in the interpretation of laboratory results. The extent of influence of the expansion ratio depends on the densimetric Froude number, grain size of the bed material and tailwater conditions. The effect is reduced as the densimetric Froude number and the tailwater depth increases. An empirical equation describing the dependency of scour depth on the densimetric Froude number, tailwater depth and expansion ratio has been developed.