TJES: Hussein BS, Jalil SA, .Hydraulic Performance for Combined Weir-Gate Structure. Tikrit Journal of Engineering Sciences 2020; 27(1): 40- 50.
References
[1] Alhamid A. A, Husain D, Negm AAM. Discharge Equation for Simultaneous Flow over Rectangular Weirs and below Inverted Triangular Weirs. Arab Gulf J Sci Res 1996;14:595–607.
[2] Negm A . A. M, Al-Brahim AM, Al-hamid AA. Combined-Free Flow over Weirs and below Gates Ecoulements Libres Combinés Sur des Déversoirs et Sous des Vannes. J Hydraul Res 2002;40:359–65.
[3] Hayawi HAA-M, Yahia AAA-G, Hayawi GAA-M. Free Combined Flow over a Triangular Weir and Under Rectangular Gate. Damascus Univ J Vol 2008;24:9–22.
[4] Dehghani A. A., Bashiri H., Shahmirzadi M., Ebrahim M., Ahadpour A.. Experimental Investigation of Scouring in Downstream of Combined Flow over Weirs and below Gates. 33rd IAHR Congr Water Eng a Sustain Environ 2009:3604–9.
Tikrit Journal of Engineering Sciences (2020) 27(1) 40- 50.
Hydraulic Performance for Combined Weir-Gate Structure
Bshkoj S..Hussein * Shaker A..Jalil
DOI: http://dx.doi.org/10.25130/tjes.27.1.06
Abstract
Combined hydraulic structure play an important role in controlling flow in open channels. This study was based on experimental and numerical modeling investigations for combined hydraulic structure. For this purpose three physical models of combined sharp crested trapezoidal weir with bottom opening and one physical model of sharp crested trapezoidal weir separately were used and tested by running eight different flow rates over each model. In which three configurations of bottom opening were tested; the first configuration is a rectangular gate while other two configuration were trapezoidal with two different side slopes of (1V:4H) and (1V:2H). The water surface profiles passing through weir-gate system were measured for all thirty two runs of all models which show uniform flow at 2.11h from the upstream of weir. The commercial computational fluid dynamic software ANSYS CFX was used to simulate flow numerically. The verification of the numerical model was based on water surface profiles and discharge which showed acceptable agreement. Also, the results showed that discharge coefficient Cd varies from (0.52-0.58). Furthermore, it was shown that both models with trapezoidal gate pass a higher discharge of flow than the model with rectangular gate with average percentage increase of discharge (40.78% and 19.40%) for trapezoidal side slopes (1H:2V and 1H:4V) respectively. In addition, the combined system with milder trapezoidal side slopes of bottom opening had a better performance for discharging weir flow which is about 40% as compared with traditional one. Finally, the empirical equations for stage-discharge relationship were estimated for all models and discharge coefficients were estimated for all runs.
863 Downloads |
Keywords: Combined system, Trapezoidal weir, Computational, Fluid dynamic, Gate flow, Discharge coefficient