The effect of installing semi-circular rotary gates in rectangular canals on flow hydraulics

Document Type : Original Article

Authors

Mehrdad Kheiraey

HojjatAllah Yonesi

Babak Shahinejad

Hassan Torabipoudeh

Ava Maraashi

Water Engineering Department, Lorestan University, Lorestan; Iran

10.22067/jfcei.2026.94812.1369

Abstract

In this study, the hydraulic performance of a semi-circular rotary gate, along with a gradual transition with three different lengths in a rectangular canal, was investigated. Experiments were conducted using various flow rates, upstream water depths, and gate opening angles. The interaction of the flow with the edge of the rotary gate causes flow division and lateral variations in the water surface. Results showed that these variations decrease as the gate opening angle increases, with the highest instability occurring at an angle of 35 degrees and the lowest at 85 degrees. The velocity and discharge on the right side of the gate were higher, but both decreased with an increase in the gate angle. The velocity on the left side was almost constant, but the discharge increased due to a larger flow cross-section. More flow was diverted to the left side with an increase in the gate opening angle. The discharge on the right side was increased while the discharge on the left was decreased by increasing the length of the gradual transition. Increasing the gate angle or reducing the transition length resulted in a greater share of flow passing through the left side overall. Energy loss increases directly with flow rate and has an inverse relationship with the gate opening angle. The highest energy loss occurred at a 35-degree opening and the lowest at 85 degrees. Finally, relationships are presented that determine the discharge through both sides of the rotary gate and the energy loss in this structure.

Keywords

Semi-Circular Rotary Gate

Energy loss

Free Flow

Flow Distribution

Rectangular Canal

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References

1. R. Henry, “Discussion of diffusion of submerged jets by M. L. Albertson, Y. B. Dai, R. A. Jensen, H. Rouse,” Transactions of the American Society of Civil Engineers, vol. 115, no. 1, pp. 665–693, 1950. [Online].
2. B. Benjamin, “On the flow in canals when rigid obstacles are placed in the stream,” Journal of Fluid Mechanics, vol. 1, pp. 227–248, 1956. [Online]. Available: https://doi.org/10.1017/S0022112056000147
3. Rajaratnam and K. Subramanya, “Flow equation for the sluice gate,” Journal of the Irrigation and Drainage Division, vol. 93, no. IR3, pp. 167–186, 1967. [Online].
4. K. Swamee, “Sluice-gate discharge equations,” Journal of Irrigation and Drainage Engineering, vol. 118, no. 1, pp. 56–60, 1992. [Online].
5. Vanden-Broeck, “Numerical calculations of the free-surface flow under a sluice gate,” Journal of Fluid Mechanics, vol. 330, pp. 339–347, 1997. [Online]. Available: https://doi.org/10.1017/S0022112096003849
6. Roth and W. H. Hager, “Underflow of standard sluice gate,” Experiments in Fluids, vol. 27, no. 4, pp. 339–350, 1999. [Online]. Available: https://doi.org/10.1007/S003480050358
7. Ferro, “Simultaneous flow over and under a gate,” Journal of Irrigation and Drainage Engineering, vol. 126, no. 3, pp. 190–193, 2000. [Online]. Available: https://doi.org/10.1061/(ASCE)0733-9437(2000)126:3(190)
8. G. Kim, “Numerical analysis of free flow past a sluice gate,” Journal of Civil Engineering, vol. 11, no. 2, pp. 127–132, 2007. [Online]. Available: https://doi.org/10.1007/BF02823856
9. Lozano, L. Mateos, G. P. Merkley, and A. J. Clemmens, “Field calibration of submerged sluice gates in irrigation canals,” Journal of Irrigation and Drainage Engineering, vol. 135, no. 6, pp. 763–772, 2009. [Online]. Available: https://doi.org/10.1061/(ASCE)IR.1943-4774.0000085
10. Belaud, L. Cassan, and J. P. Baume, “Calculation of contraction coefficient under sluice gates and application to discharge measurement,” Journal of Hydraulic Engineering, vol. 135, no. 12, pp. 1086–1091, 2009. [Online]. Available: https://doi.org/10.1061/(ASCE)HY.1943-7900.0000122
11. Habibzadeh, A. R. Vatankhah, and N. Rajaratnam, “Role of energy loss on discharge characteristics of sluice gates,” Journal of Hydraulic Engineering, vol. 137, no. 9, pp. 1079–1084, 2011. [Online]. Available: https://doi.org/10.1061/(ASCE)HY.1943-7900.0000406
12. Bijankhan, V. Ferro, and S. Kouchakzadeh, “New stage-discharge relationships for radial gates,” Journal of Irrigation and Drainage Engineering, vol. 139, no. 5, pp. 378–387, 2013. [Online]. Available: https://doi.org/10.1061/(ASCE)IR.1943-4774.0000556
13. Bijankhan and S. Kouchakzadeh, “The hydraulics of parallel sluice gates under low flow delivery condition,” Flow Measurement and Instrumentation, vol. 41, pp. 140–148, 2015. [Online]. Available: https://doi.org/10.1016/j.flowmeasinst.2014.10.017
14. Salamasi and J. Abraham, “Expert system for determining discharge coefficients for inclined slide gates using genetic programming,” Journal of Irrigation and Drainage Engineering, vol. 146, no. 12, pp. 06020013:1–9, 2020. [Online]. Available: https://doi.org/10.1061/(ASCE)IR.1943-4774.0001520
15. Khalili Shayan, J. Farhoudi, and A. R. Vatankhah, “Solutions for estimating opening of sluice and radial gates for flow regulation,” Journal of Irrigation and Drainage Engineering, vol. 147, no. 3, pp. 06021001:1–13, 2021. [Online]. Available: https://doi.org/10.1061/(ASCE)IR.1943-4774.0001541
16. Meng, L. Li, S. Zhao, and P. Li, “Flow regime discrimination and methodology for calculating discharge in trapezoidal sluice gates,” Flow Measurement and Instrumentation, vol. 100, p. 102710, 2024. [Online]. Available: https://doi.org/10.3390/w17030456
17. Hashem, A. Y. Mohammed, and T. J. Alfatlawi, “Hydraulic characteristics of labyrinth sluice gate,” Flow Measurement and Instrumentation, vol. 96, p. 102556, 2024. [Online]. Available: https://doi.org/10.1016/j.flowmeasinst.2024.102556
18. Marashi, “Hydraulics of butterfly gate: determination of specifications and application criteria in the canal,” Ph.D. dissertation, University of Lorestan, 2019. [Online]. Available:
19. Marashi, H. A. Yonesi, S. Koochakzadeh, and H. Torabi Poudeh, “Evaluation of efficiency of the butterfly gate as a structure for control and flow measurement in semi-circular canals,” Journal of Irrigation and Water Engineering, vol. 11, no. 42, pp. 1–13, 2020. [Online].
20. Marashi, S. Kouchakzadeh, H. A. Yonesi, and H. Torabi Poudeh, “Hydraulics of rotary gate: novel structure for semi-circular canals,” Journal of Irrigation and Drainage Engineering, vol. 147, no. 4, pp. 04021003:1–10, 2021. [Online]. Available: https://doi.org/10.1061/(ASCE)IR.1943-4774.0001537
21. Kheiraie, H. Yonesi, B. Shahinejad, H. Torabi Poudeh, and A. Marashi, “Laboratory investigation of the application of semi-circular rotary gate within a rectangular canal,” Environmental Water Engineering, vol. 11, no. 4, pp. 485–574, 2025. [Online]. Available: https://doi.org/10.22034/ewe.2025.537171.2045.