Abstract:
This study was conducted at the Department of Agricultural Engineering, College of Agricultural Studies (Shambat), Sudan University of Since and Technology (2013-2014).
This study was carried out with objective of testing the stability of coefficients of discharge for locally designed gate and weir operated separately and the coefficient of discharge for both openings operated simultaneously.
The combined rectangular gate under triangular weir was constructed so that the v-notch weir works over the rectangular gate. Three different
(7.5, 8.5, 10 cm) gate widths with maximum gate height of 10 cm. The V-notch weir angle is 90ᵒ. The combined weir was installed on an open cement-lined-trapezoidal channel.
The stability of the gate coefficient of discharge was tested under three different gate widths (10, 8.5, 7.5cm) each at three different heads (5.5, 4.5, 3.5cm) the result showed the stability of the gate discharge coefficient tested at different gate widths and different heads as there is no significant difference. the coefficient value reported in previous works (0.61) is quite similar to that obtained in the test (0.611)
The v-notch weir (angle 900) discharge coefficient was tested under three different heads (7,11,12cm) the results showed no significant difference. The coefficient values reported in previous works (0.53) and those obtained in the test (0.55).
The combined weir coefficient of discharge is (0.502).is quite stable as proved by statistical analysis
The combined gate under v-notch weir coefficient of discharge reported in previous works is (0.694, 0.691and 0.665) for weir angles (300 ,450 ,600) respectively. Showing the decrease in coefficient value with the increase of v-notch angle, so the coefficient of discharge value (0.502) obtained in the test compares very well.
From the above result it could be concluded that a gate under v-notch weir 900 can be designed and constructed locally to measure discharge in open channels with high reliability.
