Linear Inclined-Head-Discharge Equation for Flow Through Inclined Inverted V Notch

Ananthayya. M.B; Gicy M Kovoor; Shesha Prakash
Inverted V-Notch, as a measuring device, is found to have a near linear head-discharge relationship with the flow through the weir beyond a base-flow depth. This paper is concerned with the analysis of the flow over an Inclined Inverted V-Notch (IIVN) from a different perspective. Based on experimental work on 00 (normal), 150, 300, 450 and 600 weirs inclinations with the vertical plane across the flow direction, a generalized inclined-head-discharge equation was established for the flow through the weir. It was shown that the IIVN retains near linear discharge-head characteristics even when it is inclined to the channel bed. The discharge estimated by the linear discharge-head relationship was found to be in good agreement with the actual discharge and this was validated by the near unity regression coefficients of the same experimental data. Furthermore, the advantages of Inward Trapezoidal Weir as a flow measuring and flow control device were highlighted. With the linear head-discharge relationships and increased discharging capacity, the weir can be used in flood situations for flow measurements as the discharge can be directly read-off from the Piezometric graduations. In addition, the maintenance of uniform velocity, independent of discharge variation in sedimentation tanks or grit chambers, is an absolute necessity to settle the grit. The IIVN can maintain the uniform velocity irrespective of the variation of discharge and is highly useful in such situations.
Weirs; IVN; IIVN; Inclined-weir-discharging-index; Discharge Coefficient; Flow measurement and Afflux.
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