Experimental Study for Hydraulic Characteristics of Flow over Compound Regular Notches


The hydraulic relationships of flow through notches of different common shapes were investigated in this study. The hydraulic performance of notches were carried out experimentally, by using eight models, the effect of various shapes of notches to specify a range of hydraulic parameters such as coefficient of discharge Cd, energy dissipation ratio E%, and self-aeration of notch AE%. The experimental results of this study showed that the dissipation energy corresponding to V-notches is larger than resulted from rectangular notches. For compound notches of rectangular and triangle, a turbulence in flow increases as the angle of lower notch decreases. Thus, this type with (=120) is the most efficient between the studied models, which gives dissipation of flow energy ratio of (35.86%) for strong hydraulic jump, and (20.7%) for steady jump type. In addition, this type improved the self-aeration of flow given by ( %), a percent of 35.53 is measured. This work also reveal that length of roller and the length of hydraulic jump were directly proportional to the angle of compound notch. Depending on statistical basis, this study derived set of empirical relationships to estimate coefficient of discharge, energy dissipation ratio, and reduction of hydraulic jump length ratio with acceptable values of coefficient of determination