Generalized Head-Discharge Equation for Flow over Sharp-Crested Inclined Inverted V-Notch Weir

Abstract

The sharp-crested weir is the most commonly used device in channels for flow measurement and flow regulation due to its simplicity. Attempts have been made to study in detail the flow over different shapes of normal conventional weirs, side weirs, and oblique weirs. Most of the investigators have expressed the discharge coefficient as a function of various parameters. The concern of this paper is to study flow over an inclined inverted triangular notch weir. Based on experimental work on 0° (normal) and 15, 30, 45, and 60° weirs, the writers have established an equation for discharge in terms of the inclination angle of the weir plane with the plane normal to the flow axis. A new general algebraic optimization procedure has been developed for evolving a linear head-discharge relationship for an inclined inverted V-notch (IIVN), which is relatively superior to similar procedures developed earlier. It has been shown that the IIVN does not lose its near-linear discharging characteristics even when it is inclined to the channel bed. The discharge estimated by the linear discharge-head relationship has been found to be in good agreement with the actual discharges well within a ±5% error. Further, the advantages of the IIVN as a flow measuring and flow control device have been highlighted.