Calibration of Submerged Radial Gated with Non-linear Optimization

Document Type : Research Paper


1 Water Engineering Dept., Agricultural and Natural Resource Univ. of Ramin.

2 - Prof., Civil Engineering Dept., Faculty of Engineering, Shahid Chamran Univ. of Ahwaz.

3 Member of Young Res. Club, Islamic Azad Univ. of Gonabad.


Gates are used in different applications and shapes as water regulation structures. The radial gate is one of the most common water control structure in irrigation and drainage networks. Ease of construction, installation, and power saving nature, can be considered as the main advantages of radial gates. These benefits leaded to increase of their application for controlling the flow in dams and water conveyance structures. Many methods and empirical equations have been presented to estimate the discharge and discharge coefficient from radial gates. However, submerged flow condition has been less considered. Discharge calculation from the gate opening, could be carried out with the integrated solution of energy and momentum equations. In this research, 16 measured discharges were used in two intakes of diversion dams of Gotvand and Shohada in Khuzestan State of Iran. The results indicated that the momentum equation always underestimates the submerged depth due to disregarding of flow turbulence and non-uniformity of the velocity distribution. Thus, calculated discharge is always greater than measurement ones. Therefore, through direct measurement of submerged depth instead of tail water (the omission of momentum equation) and using energy equation, the results would be closer to the true values. Finally, Toch contraction coefficient has been calibrated using integrated solution of energy and momentum equations in Lingo software (non-linear optimization tool).