THE 2A TRIANGULAR WEIR DESIGN, THEORY, AND EXPERIMENT

B. ACHOUR, L. AMARA

Abstract


The 2A triangular weir is a new type of weir that belongs to the category of weirs with a triangular longitudinal profile. The current device has the same upstream and downstream slopes as the Crump weir. The study intends to derive the theoretical relationship that governs the discharge coefficient Cd of the device and hence that of the flow rate Q, known as the stage-discharge relationship. For this, the energy equation, involving the approach flow velocity, is applied between two judiciously chosen sections of the free flow crossing the weir under critical state conditions. The resulting equation is transformed into dimensionless terms, and the discharge coefficient is derived by comparison with the well-known stage-discharge relationship of triangular weirs. Another method, based on the kinetic factor, is also applied and leads to the same result. The theoretical discharge coefficient relationship shows that only the relative weir height is the influential parameter, as predicted by the dimensional analysis. The shape of the approach channel has no influence either on the discharge coefficient Cd or on the flow rate Q. This feature gives the device a universal range since its use can be extended to any shape of the approach channel.


Keywords


Novel type weir, 2A weir, Stage-discharge relationship, Discharge coefficient, Experimental validation.

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References


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