NORMAL DEPTH COMPUTATION IN A RECTANGULAR OPEN-CHANNEL WITH CIRCULAR SIDES USING THE ROUGH MODEL METHOD (RMM)

B. MANSRI, M. LAKEHAL, A. BEDJAOUI, L. HACHEMI-RACHEDI, S. BOUSLAH, B. ACHOUR

Abstract


The computation of normal depth in open channels is a topical field in the practice of hydraulic engineers. Many methods consider Chezy’s resistance coefficient or Manning’s roughness coefficient as given data when calculating the normal depth. This seems unjustified since these coefficients depend in particular on the normal depth sought. The objective of this study is to propose an explicit method allowing the calculation of the normal depth in a rectangular channel with a horizontal bottom and circular walls using the rough model method (RMM), which is based on parameters that are easily measurable in practice. These parameters are the discharge, longitudinal bed slope, absolute roughness and kinematic viscosity. After establishing the equations governing the geometric and hydraulic characteristics of the referential rough model, the study shows that the normal depth sought is equal to the normal depth in the referential rough model corrected for the effects of a nondimensional correction factor.

Keywords


Discharge, Normal depth, Rectangular Open Channel with Circular Sides, Slope, Turbulent flow, Uniform flow.

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References


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