Expansion Ratio Effects on Scour by 3D Jets

The influence of channel expansion ratio (ratio of channel width-to-nozzle size) on the scour geometry at various tailwater depths caused by submerged square jets is studied.Results show that the extent of influence of the expansion ratio depends on the densimetric Froude number, grain size of the bed material and tailwater conditions.Further, the effect of channel expansion ratio 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.