Experimental Investigating the Effect of Relative Curvature of a Channel Bend on the Inlet Flows in Bilateral Water Intakes of Weirs with Horizontal and Sloping Crests

Document Type : Research Paper


1 Water engineering department, Faculty of Agriculture, Urmia University, Urmia, Iran.

2 Department of Water Engineering, Faculty of Agriculture, Urmia University, Urmia, Iran

3 Department of Irrigation and Reclamation Engineering, College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran


There are evidences of the construction of weirs and diversion dams in river bends, and the necessities for building water intakes on both sides of the river bend. The construction of weirs in rivers reaches encounters problems in terms of asymmetry of flow distribution into the intake structures on both sides of the river. The purpose of this study is to investigate the effect of relative curvature on the ratio of the inlet discharge of bilateral water intakes from a weir in a channel bend. The experiments were carried out in three laboratory channels with different relative curvatures (i.e. 3.3, 2.55 and 0.84), which falls into the category of mild, moderate and sharp bends. A broad-crested weir with two types of horizontal and sloping crests was installed at an angle of 60 degrees from the bend inlet. Two intakes were located next to the inner and outer banks. The results indicated that the weir installation in the mild bend performed better uniformity of intake discharges on both channel sides. The performance of sloping crest weir was superior compare with the horizontal crest weir. With the sloping crest weir, average inlet discharge into the inner and outer intakes increased by 8%, 4% and 8%, in three bends of  relative curvatures 3.3, 2.55 and 0.84, respectively, compared to the horizontal crest weir. Considering the sloping crest weir, the discharge ratio of the outer to inner intakes in the three mild, moderate and sharp bends was 1.00, 1.10 and 1.12, respectively. Increasing the channel discharges would result in more uniformity of inflows in the inner and outer banks in the three bends with different relative curvatures.


Abdollahpour, M., Yasi, M., Behmanesh, J. & Vaghefi, M. (2013). Experimantal investigation of sloping sharp crested weir in a channel bend. Iranian Journal of Watershed Management Science and Engineering, 7(22), 79-82. (in Farsi)
Anjum, N., Ghani, U., Ahmed Pasha, G., Latif, A., Sultan, T. and Ali, S., 2018. To Investigate the Flow Structure of Discontinuous Vegetation Patches of Two Vertically Different Layers in an Open Channel. Water, 10(1), p.75.
Asnaashari A, Merufinia E., 2015. Numerical Simulation of Velocity Distribution in the River Lateral Intake Using the SSIIM2 Numerical Model. Cumhuriyet Science Journal, 36(3): 1473-1486.
Biswal, S.K., Mohapatra, P. and Muralidhar, K., 2016. Hydraulics of combining flow in aright-angled compound open channel junction. Sadhana, 41(1), pp.97-110.
Boss, M. G. 1988. Discharge Measurement Structures. ILRI Pub. Wageningen.
Farhadi, A., & Yasi, M. (2020). Study of the effect of sloping-broad crested weir on the uniformity of flow into bilateral intakes in a channel bend. Journal of Water and Irrigation Management, 10 (13), 317-330. (in Farsi).
Gravandi, E., A. Kamanbeadst, A. R. Masjedi, M. Heidarnejad and A. Bordbar. 2018. Laboratory investigation of the impact of armor dike simple and l-shaped in upstream and downstream intake of the hydraulic flow river and intake flow rate. JWSS-Isfahan University of Technology. 22(3): 55-70.
Gómez-Zambrano, H.J., López-Ríos, V.I. and Toro-Botero, F.M., 2017. New methodology for calibration of hydrodynamic models in curved open-channel flow. Revista Facultad de Ingeniería Universidad de Antioquia, (83), p.82.
Goudarzizadeh R, Hedayat N, & Jahromi S., (2010). Three-dimensional simulation of flow pattern at the lateral intake in straight path, using finite-volume method. World Academy of Science, Engineering and Technology, 47, 656-661.
Haddad, H. Ahmad, E. & Azizi, K. (2017). Numerical simulation of the inlet sedimentation rate to lateral intakes and comparison with experimental results. Journal of Research on Ecology, 5(1):464 - 472.
Heidarirad P, Kamanbedast A A, Heidarnezhad M, Masjedi A R, Hasoonizadeh H. The Effect of Convergence and Divergence on Flow Pattern and Sediment Transport in Lateral Intakes. JWSS. 2020; 24 (1) :69-82.
Herrero, A., Bateman, A., Medina, V., (2015). Water flow and sediment transport in a 90° channel diversion: an experimental study. J. Hydraul. Res. 53, 253–263. http://dx. doi. org/ 10.1080/ 00221686. 2014.989457.
hosseini mobara, E. & Yasi, M. (2016).  Performance of Crump Weirs in a Channel Bend. Iranian Water Researches Journal, 10(1), 59-67. (in Farsi).
Kamanbedast, A. A., S. Akib and K. Khadem. 2018. Investigation of epi structure in frontal of intakes on diversion flow in river bend with cche2d model. Feb-Fresenius Environmental Bulletin. 23(12): 807-918.
Mignot, E., et al.,( 2013). Impact of topographic obstacles on the discharge distribution in open-channel bifurcations. J. Hydrol. 494, 10–19. http://dx.doi.org/10.1016/j. jhydrol.2013.04.023.
Mignot, E., et al., (2014). Analysis of flow separation using a local frame axis: application to the open-channel bifurcation. J. Hydraul. Eng. 140, 280–290. http://dx.doi.org/10. 1061/(ASCE)HY.1943-7900.0000828.
Mirzaei, S.H.S., Ayyoubzadeh, S.A. and Firoozfar, A.R., 2014. The Effect of Submerged-Vanes on Formation Location of the Saddle Point in Lateral Intake from a Straight Channel. American Journal of Civil Engineering and Architecture, 2(1), pp.26-33.
Momplot, A., Lipeme Kouyi, G., Mignot, E., Rivière, N., Bertrand-Krajewski, J.-L., (2017). Typology of the flow structures in dividing open channel flows. J. Hydraul. Res. 55, 63–71. http://dx.doi.org/10.1080/00221686.2016.1212409.
Ouyang, H.T. & Lin, C. P. (2016). Characteristics of interactions among a row of submerged vanes in various shapes. Journal of hydro-environment research, (13), 14-25.
Ramamurthy, A.S.; Junying Q.U. and Diep, V.O. (2007). Numerical and experimental study of dividing open-channel flows. Journal of Hydraulic Engineering, 133(10):1135-1144.
Rozovskii, I.L. (1957). Flow of Water in Bends of Open Channels. Academy of Sciences of the Ukrainian SSR, Kiev, 233 p.
Serajian, T.M., Kamanbedast, A., Masjedi, A., Heidarnejad, A. and Hasonizadeh, A. (2020). Laboratory evaluation of the combined effect of convergence and submerged vanes on lateral Intakes’ sediment input at 90⁰ river bends. Ain Shams Engineering Journal, 245-252.
Seyedian S M, Bajestan M S, Farasati M., 2014. Effect of bank slope on the flow patterns in river intakes. Journal of Hydrodynamics, Ser. B, 26(3), 482-492.
Schindfessel, L., Creëlle, S. and De Mulder, T., 2017. How Different Cross-Sectional Shapes Influence the Separation Zone of an Open-Channel Confluence. Journal of Hydraulic Engineering, 143(9), p.04017036.
Vaghefi, M., Ghodsian, M., Soleymani, B. and Akbari, M. (2014). Numerical Study Of The Effect Of Radius Of Curvature On The Flow Pattern Around A T-Shaped Spur Dike Located At A 90 Degree Bend With A Rigid Bed. Journal of  WATER ENGINEERING, Volume 7 , Number 22; Page(s) 51 To 61.
Valimohamadi, A. & Yasi, M. (2016). Hydraulic Evaluation of Horizontal and Sloping Broad-Crested Weirs in a Channel Bend. Journal of Applied Research in Irrigation and Drainage Structures Engineering, 16(65), 55-70. (in Farsi).
Xu, M., Chen, L., Wu, Q., Li, D., 2016. Morph- and hydro-dynamic effects toward floo conveyance and navigation of diversion channel. Int. J. Sediment Res. 31, 264–270.http://dx.doi.org/10.1016/j.ijsrc.2015.09.001.
Zahiri, A. and Najafzadeh, M., 2018. Optimized expressions to evaluate the flow discharge in main channels and floodplainsusing evolutionary computing and model classification. International Journal of River Basin Management, 16(1), pp.123-132.