Computation of Normal Depth in a U-Shaped Open Channel Using the Rough Model Method
[1]
Bachir Achour, Department of Civil and Hydraulic Engineering, Research Laboratory in Subterranean and Surface Hydraulics (LARHYSS) University of Biskra, Biskra, Algeria.
The rough model method is applied in order to explicitly computing normal depth in a U-Shaped channel. Simple relationships are obtained by using the geometric characteristics of a triangle. The Darcy-Weisbach relationship is applied to a rough model in order to establish the equation of the flow. The resulting equation is implicit towards the aspect ratio and its resolution is possible through a simple numerical procedure which consists in approaching successively the solution. The process of calculation is not constraining since the solution is obtained, in the worst case, at the end of the eighth step of calculation. Once the aspect ratio in the rough model is calculated, the aspect ratio and therefore the non-dimensional normal depth in the current channel is derived through a dimensionless correction factor of linear dimension. A practical example is proposed to better assessing the reliability and the simplicity of the advocated method.
Rough Model Method, Normal Depth, U-Shaped Channel, Discharge, Longitudinal Slope, Open Channel
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