Journal of New Approaches in Water Engineering and Environment
Scientific Journal

Investigating the Discharge Coefficient and Efficiency of the Pivot Side Weirs with Threshold

Document Type : Original Article

Authors

Hooman Kheybar 1
Seyed Mohsen Sajjadi 2
Javad Ahadiyan 3
Mehdi Ghomeshi 3

1 Hydraulic Structures Department, Faculty of Water and Environmental Engineering, Shahid Chamran University of Ahvaz, Ahvaz. Iran.

2 Assoiciated Professor, Hydraulic Structures Department, Faculty of Water and Environmental Engineering, Shahid Chamran University of Ahvaz, Ahvaz, Iran.

3 Professor, Hydraulic Structures Department, Faculty of Water and Environmental Engineering, Shahid Chamran University of Ahvaz, Ahvaz. Iran.

https://doi.org/10.22034/nawee.2024.467874.1096
Abstract
In this research, the flow coefficient and efficiency of the pivot side weir with the flow threshold under different opening angles towards the side channel were investigated. The weir model built in this research consists of a threshold part with a fixed right angle and an inclined hinge part with the ability to change the angle. the performance of three models with a ratio of 1.5, 1 and 0.75 were examined and their flow coefficient and efficiency were calculated. According to the laboratory results, it was observed that for all the numbers of the upstream landing, with the increase of the opening angle towards the side channel, the discharge coefficient of different models is on average about 30 to 60% and the efficiency is about 20 to 45% compared to the control model. rectangular weir with a sharp vertical edge) will increase. Next, a linear relationship was obtained in order to calculate the flow coefficient of the laboratory models. R^2 of this relationship is equal to 0.72 and the NRMSE and WQD error values for it were calculated as 0.6 and 0.02, respectively. The results of this research showed that the opening of the model facing the side channel under different angles leads to an increase in the flow coefficient and weir efficiency and will have a positive effect on the performance of the pivot side weir. By verifying the accuracy of the linear relationship obtained in this research, it can be concluded that the mentioned equation is accurate.

Keywords

Weir threshold
spatially varied flow
efficiency
Side Weirs
Pivot Weirs
discharge coefficient
Abdi Chooplou, C., Ghodsian, M., Vaghefi, M., Kazerooni, S. and Bodaghi, E. 2022. Experimental Study of Effect of Flow Drop Height on Downstream Bed Topography of Type-A Trapezoidal Piano Key Weir. Journal of New Approaches in Water Engineering and Environment. DOI: http//doi.org/10.22034/nawee.2023.345240.1009. (In Persian).
Afzalian, A., sajjadi, S. M., shafai bajestan, M., Ahadiyan, J. (2022). 'Experimental investigation of the effect of the height of the trapezoidal piano key side weir on the discharge coefficient and water level profiles.', Irrigation and Drainage Structures Engineering Research, 23(87), pp. 47-76. doi: 10.22092/idser.2022.359228.1518. (In Persian)
Ahadiyan, J., Abbasi Chenari, S., Azizi Nadian, H., Katopodis, C., Valipour, M., Sajjadi, S. M., & Omidvarinia, M. (2024). Sustainable systems engineering by CFD modeling of lateral intake flow with flexible gate operations to improve efficient water supply. International Journal of Sediment Research, 39(4), 629-642. https://doi.org/10.1016/j.ijsrc.2024.05.003.
Ahadiyan, J., Sadeghi, B., Shafai Bajestan, M., Sajjadi, S. M. (2024). 'Effect of longitudinal training wall (LTW) on improving the inlet flow pattern at the side channel intakes', Advanced Technologies in Water Efficiency, 4(4), pp. 51-67. doi: 10.22126/atwe.2024.10776.1128. (In Persian).
Arvanaghi, H., Naderi, V., Azimi, V., and Salmasi, F. 2014. "Determination of discharge coefficient in inclined rectangular sharp-crested weirs using experimental and numerical simulation." J. Curr. Res. Sci., 2(3), 401–406.
Azimfar, S. M., Hosseini, S. A., and Khosrojerrdi, A. 2017. "Derivation of Discharge Coefficient of a Pivot Weir under Free and Submergence Flow Conditions"., Flow Measurement and Instrumentation, https://doi.org/10.1016/j.flowmeasinst.2017.11.010
Bakshaei, Sh., Sajjadi, S. M. and Ahadian, J. 2022. "Laboratory investigation of the determination of the discharge coefficient of the pivot pivot side weir." The 6th international conference on technology development of water science, watershed management and river engineering. (In Persian)
Bakhshaei, Sh., Sajjadi, S. M. and Ahadian, J. 2022. "Investigation of the physical model of the pivot side weir and the optimal efficiency of the discharge coefficient." The 6th international conference on technology development of water science, watershed management and river engineering. (In Persian)
Bagheri, N., Eghbalzadeh, A., and Javan, M. 2021. “The Effect of Downstream Water Depth on Hydraulic Jump Characteristics along Side Weir.” Journal of Water and Soil Science. 28: 3. 195-208. (In Persian)
Bijankhan, M., & Ferro, V. 2018. “Experimental Study and Numerical Simulation of Inclined Rectangular Weirs.” Journal of Irrigation and Drainage Engineering. 144. 10.1061/(asce)ir.1943-4774.0001325.
Brater, E.F., and King, H.W. 1976. "Handbook of Hydraulics." 6th ed. McGraw-Hill, New York. 584 pp.
Chenari, S. A., Nadian, H. A., Ahadiyan, J., Valipour, M., Oliveto, G., & Sajjadi, S. M. (2024). Enhancing Hydraulic Efficiency of Side Intakes Using Spur Dikes: A Case Study of Hemmat Water Intake, Iran. Water, 16(16), 2254. https://doi.org/10.3390/w16162254.
De Marchi, G. 1934. Essay on the performance of pivot weirs. L Energia Electrica Milano, Italy, 11: 11. 849-860.
Fathi-Moghadam M, Salmanzadeh S, Ahadiyan J, Sajadi M. (2024). Drag coefficient of rigid and flexible deciduous trees in riparian forests. Journal of Hydraulic Engineering, ASCE, 150(5):04024027.
Hajialigol, S.; Ahadiyan, J.; Sajjadi, M.; Scorzini, A.R.; Di Bacco, M.; Shafai Bejestan, M. (2021). Cross-beam dissipaters in abruptly expanding channels: Experimental analysis of flow patterns. Journal of Irrigation and Drainage Engineering, ASCE, 147, 06021012.
Hulsing H. 1967. "Measurement of peak discharge at dams by indirect methods". U.S. Geol. Survey Techniques Water-Resources Inv., book 3, chap. A5, pp. 29.
Iranpour, A., Egdernezhad, A., & Heidarnejad, M. 2024. Numerical investigation of energy losses in baffled piano key weirs, Journal of New Approaches in Water Engineering and Environment. 3:1. 55-70. DOI: http//doi.org/10.22034/nawee.2024.451817.1069. (In Persian).
Kheybar, H., Sajjadi, S. M., & Ahadiyan, J. (2021). Effect of sudden canal contraction on the discharge coefficient and the energy dissipation coefficient of the elliptical LOPAC gate*. Irrigation and Drainage, 70(5), 1145-1154. https://doi.org/10.1002/ird.2622.
 
Kindsvater, C. E., and Carter, R. W. 1957. "Discharge characteristics of rectangular thin plate weirs". Journal Hydraulic. Division. 83(6), 1–36.
Neisi M, Sajadi M, Shafai Bejestan M, Ahadiyan J. (2024). Experimental Study of Flow over the Triangular Side Weir with Inclined Crest in Subcritical Flow. Journal of Water and Soil Sciences, 28 (3) :117-129.( In Persian)
Parvaneh, A., Parvaneh, M., Rakhshandehroo, G., Jalili Ghazizadeh, M. R. and Sadeghian, H. 2022. Discharge Characteristics of a Novel Inclined-Bed Triangular Side Weir in Subcritical Flow. Journal of Irrigation and Drainage Engineering. 148. 10.1061/(ASCE)IR.1943-4774.0001651.
Sajjadi, S. M., Barihi, S., Ahadiyan, J., Azizi Nadian, H., Valipour, M., Bahmanpouri, F., & Khedri, P. (2024). Redesigning the Fuse Plug, Emergency Spillway, and Flood Warning System: An Application of Flood Management. Water, 16(24), 3694. https://doi.org/10.3390/w16243694.
Schoder, E.W., and Turner, K.B. 1929. "Precise Weir Measurements." Trans. ASCE, 93, 999-1110.
Sheikh Rezazadeh Nikou, N., Monem, M. J., Safavi, K. (2015). 'Extraction of flow Rate Equation under Submerged Flow Condition and Determining of Related Coefficients in Pivot Weirs with the Different Side Contractions', Iranian Journal of Irrigation & Drainage, 9(5), pp. 691-700. (In Persian)
Saffar, S., Solimani Babarsad, M., Mahmoodian Shooshtari, M., Poormohammadi, M. H., Riazi, R. (2022). 'Experimental study of flow converging section side weir hydraulics', Journal of Marine Science and Technology, 21(3), pp. 23-32. doi: 10.22113/jmst.2021.253749.2401. (In Persian).
USBR. 1948. "Studies of Crests for Overfall Dams." Bulletin 3. Boulder Canyon Project, Final Report. United States Bureau of Reclamation, Denver.
Wahlin B.T., and Replogle J.A. 1994. "Flow Measurement Using an Overshot Gate". United States Department of the Interior Bureau of Reclamation, under Cooperative Agreement NO.1425-2-FC-81-19060 entitled Water Conservation Innovative Technology Research for Agriculture and Urben Irrigation Water.
Journal of New Approaches in Water Engineering and Environment
Volume 3, Issue 2
September 2025
Pages 72-88

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