A Hydraulic Study of Sharp Crested Weir with Orifices.

Document Type : Research Studies

Author

Lecturer, Irrigation And Hydraulics Engineering Department , Shoubra faculty of engineering, Benha University, PO box 11629, Shoubra, Egypt

Abstract

This research investigates experimentally the flow over sharp crested weir and through rounded orifices. Nine symmetrical orifices of 3 cm diameter each were made in the weir to convey much water in the downstream direction. The orifices were distributed as 3 equals spaced rows by three equal spaced columns. Twenty three (23) experimental runs were conducted. Nine weir models were used. This study aimed to evaluate the effect of discharge, tail gate water level, orifices number, and locations on the discharge coefficient and length of hydraulic jump. Results were analyzed and graphically presented. The results of flow over the weir with orifices were compared with those of the weir without orifices. It was dedicated that there is a large difference between them. In case of weir with opening it was found that the discharge coefficient was higher than the weir without openings. The jump length was inversely proportional to the number of openings. Multiple regression equations based on energy principal and dimensional analysis theory were developed for computing the discharge coefficient and hydraulic jump length over sharp crested weir with orifices. The developed equations were compared to the experimental data. The comparison confirms a good reliability and high accuracy.

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