References

75504

Magazine of Civil Engineering

2712-8172

10.34910/MCE.142.7

Hydraulic analysis of a combined system: rectangular weir with a rectangular gate

0000-0001-6244-7965

Alasadi

Layth Abdulrasool

laitha.alasadi@uokufa.edu.iq Al-Yousefi

Hayder

Haydera.Alyousefi@uokufa.edu.iq Kadhem

Ali

alik.hussein@uokufa.edu.iq

University of Kufa Department of Chemical Engineering, University of Kufa

06 04 2026

19 2

142

14207 14207

This study explores the hydraulic analysis of a combined system of rectangular sharp-crested weirs and rectangular gates, essential to control water flow in various applications. The weirs and gates are used for flow measurement in water distribution systems, reservoirs, sewage systems, and irrigation networks. The study aims to optimize design and operational strategies for the combined system, contributing to the field of hydraulic engineering. Five models of compound rectangular weirs with rectangular gates were tested using a downstream support. The first three models had a gate width of 10 cm, while the remaining two had a lower opening width of 10 cm and gate widths of 8 cm and 6 cm. The discharge coefficient increases with water head ratio as shown in experimental runs with gate width = 10 cm and lower weir width = 10. The discharge coefficient rises by 10.81 % due to a decrease in the lower opening weir with a constant gate width. It increases by 29.14 % as the gate width decreases with a continuous lower opening.

combined system weir gate hydraulic analysis

References

Teol, S.A., Dzhagers, B., Suryadi, F.S., De Freytyur, S. The role of gate operation in reducing problems with cohesive and non-cohesive sediments in irrigation canals. Water. 2019. 11(12). Art. no. 2572. DOI: 10.3390/w11122572

Hussein, B.S., Jalil, S.A. Hydraulic performance for combined weir-gate structure. Tikrit Journal of Engineering Sciences. 2020. 27(1). Pp. 40–50. DOI: 10.25130/tjes.27.1.06

Altan-Sakarya, A.B., Kökpınar, M.A. Computation of discharge for simultaneous flow over weirs and below gates (H-weirs). Flow Measurement and Instrumentation. 2013. 29. Pp. 32–38. DOI: 10.1016/j.flowmeasinst.2012.09.007

Balouchi, B., Rakhshandehroo, G. Using physical and soft computing models to evaluate discharge coefficient for combined weir-gate structures under free flow conditions. Iranian Journal of Science and Technology – Transactions of Civil Engineering. 2018. 42(4). Pp. 427–438. DOI: 10.1007/s40996-018-0117-0

Mirnaseri, M., Emadi, A. Hydraulic performance of combined flow rectangular labyrinth weir-gate. Middle-East Journal of Scientific Research. 2013. 18(9). Pp. 1335–1342. DOI: 10.5829/idosi.mejsr.2013.18.9.12374

Nouri, M., Sihag, P., Kisi, O., Hemmati, M., Shahid, S., Adnan, R.M. Prediction of the discharge coefficient in compound broad-crested-weir gate by supervised data mining techniques. Sustainability. 2022. 15(1). Art. no. 433. DOI: 10.3390/su15010433

Parsaie, A., A. Haghiabi, H., Saneie, M., Torabi, H. Prediction of discharge coefficient of cylindrical weir-gate using adaptive neuro-fuzzy inference systems (ANFIS). Frontiers of Structural and Civil Engineering. 2017. 11. Pp. 111–122. DOI: 10.1007/s11709-016-0354-x

Qasim, R.M., Abdulhussein, I.A., Hameed, M.A., Maatooq, Q.A. Experimental study of coupled parabolic weir over flow and gate under flow rate. Journal of Information Engineering and Applications. 2018. 8(4). Pp. 34–42.

Sarhan, S.A., Jalil, S.A. Analysis of simulation outputs for the mutual effect of flow in weir and gate system. JUBES. 2018.26(6). Pp. 48–59.

Arora, K.R. Fluid Mechanics, Hydraulics and Hydraulic Machines. Delhi: Standard Publishers, 2005. 1116 p.

United States Bureau of Reclamation. Water Measurement Manual. 3rd edn. Denver, CO: U.S. Department of the Interior, Bureau of Reclamation, 1997. 317 p.

Bos, M.G. Discharge Measurement Structures. Wageningen: International Institute for Land Reclamation and Improvement, 1989. 401 p.

White, F.M. Fluid Mechanics. 4th edn. Boston, MA: McGraw-Hill, 1998. 1023 p.

Alasadi, L.A.R., Khlif, T.H., Hassan, F.A. Experimental investigation for the local scour around V-shaped spur-dikes. Scientific Review Engineering and Environmental Sciences. 2023. 32(1). Pp. 69–86. DOI: 10.22630/srees.4506

Qasim, R.M., Abdulhussein, I.A., Al-Asadi, K. Experimental study of composite inclined weir-gate hydraulic structure. WSEAS Transactions on Fluid Mechanics. 2020. 15. Pp. 54–61. DOI: 10.37394/232013.2020.15.5

Sahib, J.H., Al-Waeli, L.K., Jaber Al Rammahi, A.H. Utilization of ANN technique to estimate the discharge coefficient for trapezoidal weir-gate. Open Engineering. 2022. 12(1). Pp. 142–150. DOI: 10.1515/eng-2022-0030

Yousif, O.S.Q., Karakouzian, M. Effect of Corner Shape on Hydraulic Performance of One-Cycle Rectangular Labyrinth Weirs. Fluids. 2020. 5(3). Article no. 117. DOI: 10.3390/fluids5030117

Eltoukhy, M.A.R., Abdelhaleem, F.S., Nasralla, T.H., Shaban, S. Effect of compound weir and below circular gate geometric characteristics on its discharge coefficient. International Journal of Scientific & Engineering Research. 2020. 11(10). Pp. 1115–1130.

Alizadeh Sanmi, F. Experimental and numerical investigation of flow around a semi-cylindrical weir-gate. M.Sc. thesis. Sari: Dept. Agric. Eng., Sari Agricultural Sciences and Natural Resources Univ., 2014.

Khassaf, S.I., Abbas, H.A. Coefficient of discharge for a compound weir combined with semi-circular gate. International Journal of Advance Research. 2013. 1(9).

Severi, A., Masoudian, M., E. Kordi, Röttcher, K. Experimental investigation on discharge coefficient changes of moveable cylindrical weir-gate. Current Trends in Technology and Science. 7thSASTech 2013. Bandar-Abbas: Khavaran Institute of Higher Education, 2013. Pp. 7–10. URL: https://www.researchgate.net/publication/299489929 (date of application: 10.08.2026).

Hassan, F.A., Khassaf, S.I., Omran, H. A. Determining the coefficient of discharge due to flow over composite weir and below gates. Asian Transactions on Engineering. 2015. 5. Pp. 1–6. DOI: 10.13140/RG.2.2.33844.86406

Khassaf, S.I., Abbas, H.A. Study the free flow over compound weir and below semi-circular gate. International Journal of Scientific & Engineering Research. 2013. 4(10). Pp. 1486–1491.