Coefficient of discharge for a combined hydraulic measuring device

الملخص EN

The aim of this study is to investigate the coefficient of discharge for a combined hydraulic measuring device.

For this purpose nine combined models were constructed and manufactured of an aluminum plates of 2 mm thick, the shapes of the models are of rectangular weir with different width ( B = 8, 10, 12 cm)is used over a semi-circular gate of a constant diameter (d = 12 cm) the distance below the weir edge and the semi-circular gate y is changed three times ((y = 5, 10, 15 cm).

The analysis of results show that Cd increase as (h / d) increase and for a constant value of (h / d) Cd increase as the width B increase, the values of Cd range from around 0.522 to 0.853 with an average of 0.695.

Also Cda decrease as the parameter (y / d), (B / d) and (b / W) increase and at a constant values of that parameters Cda increase as y increase, and the values of Cda range from around 0.61 to 0.74.

A multi regression model to estimate Cd for the combined device is estimated with percentage of error ± 10 %.