Abstract

One of the most important hydraulic structures which are used in irrigation systems
are the broad crested weirs, which can be defined as a vertical barrier in a canal or tank
side in which the water may flow freely. This weir can be used to measure the
discharge and to raise the water level in the upstream. In this study the effect of
longitudinal section on streamlined flow over broad crested weir has been investigated.
Loss in energy, working efficiency and the coefficient of discharge have been
considered. Experimental study carried out using (25) samples with six different
hydraulic heads. The analysis of results indicate that the coefficient of discharge (Cd)
increases with increasing Froud Number (Fr) and the most effective slope of upstream
and downstream faces of the weir wear (45°) and (60°) respectively, at which the
coefficient of discharge demonstrated was (0.644