Experimental Investigation On Hydraulic Performance Of Non-Rectangular Piano Key Weir (PKW)

Abstract

A piano key weir PKW is a type of nonlinear weirs which is usually used for small control structures footprint. An experimental investigation has been carried out to study the hydraulic performance of non-rectangular piano key weirs. A type – A standard rectangular PKW and three non-rectangular PKWs were tested in this investigation. The non-rectangular PKW carried the same characteristics of rectangular PKW except, that the side wall angle was changed in each model. Experiments conducted in 10 m length, 0.6 m width and 0.6 m deep rectangular channel. The effects of side wall angle on discharge coefficient and discharge efficiency were investigated. The results showed that the deviation of side wall angle from zero degree has a negative impact on the hydraulic performance of PKW. Increasing the side wall angle to 3 degrees, 5 degrees and 7 degrees has led to a decrease in discharge coefficient by 4%, 12% and 18%, respectively.