Numerical modeling of the effect of elliptical elongation on the hydraulic performance of an elliptical Lopac gate

Document Type : Research Paper

Authors

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

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

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

Abstract

Gates are Flow control structures used in irrigation canals. In the meantime, Lopac Gates have very efficient capabilities such as controlling and regulation the level of water upstream, automation, lower energy consumption than other types of gates (like sliding gate, radil gate) and the possibility of passing floating objects. Elliptical Lopac gate (ELG) are one of the new types of lopac gates that are intended to increase the discharge coefficient compared to other types of lopac gates. The present study was conducted with the aim of modeling ELG in five different elliptical ratios with sudden transition in the channel using Flow3d software. All models are considered in three discharges of 25, 35 and 45 liters per second and in three openings of 20, 30 and 40 cm and simulation has been done with RNG turbulence model. The final results showed that by increasing the elliptical ratio from 0.7 to 1.28, the energy consumption gates ​​will decrease from eight to 20 percent compared to the initial energy. In the study of floor shear stress, the results show that by increasing the elliptical ratio, the average shear stress decreases by 52 percent. In the section on flow vortices, the results show that in elliptic ratios greater than one, vortex currents and current deviation from the path are reduced and the flow rate decreases from 22 to 54 percent.

Keywords

Main Subjects


  1. Aqua Systems 2000 Incorporation (AS21). (2013). Leaders in Water Management and Control. Retrieved from: http://www.as2i.net/products/control-gates/hydra-lopac- gate.
  2. Babaei Faqihmahaleh, R., Ismaili Varki, M., & Shafiee Sabet, B. (2018). Investigation of the effect of geometric characteristics and hydraulic conditions on the performance of the salon-partial flow flow adjustment structure. Iranian Soil and Water Research, 49 (4), 727-717. (In Persian)
  3. Badiee, S., & Sajadi, M. (2018). Numerical analysis of the hydraulic conditions of the Lopac gate using Fluent Software. In: Proceeding of International Conference on Civil Engineering, Architecture and Urban Development Management in Iran.TEHRAN,9 December, University of Tehran. (In Persian)
  4. Kheybar, H., Sajadi, M., & Ahadyan, J. (2021). Effect of sudden canal contraction on the discharge coefficient and the energy dissipation coefficient of the elliptical LOPAC gate. Irrigation and Drainage, 1-10. (In Persian)
  5. Monem, M.J., & Naghayi, R. (2013). Introduction of lopac gate to regulate water level in irrigation canals and present its hydraulic relations. in: Proceeding of 4th National Conference on Management of Irrigation and Drainage Networks, Shahid Chamran university of Ahvaz. (In Persian)
  6. Monem, M.J., & Sadeghi, S. (2014). Testing the use of Lopac Gate in irrigation networks and comparing them with conventional structures using the ICSS mathematical model, Ministry of Science, Research and Technology, Tarbiat Modares University, College of Agriculture. (In Persian)
  7. Pilbala, A., Sajjadi, M., & Bejestan, M.S. (2021). Hydraulic performance of elliptical-LOPAC gate under submerged flow conditions. Ain Shams Engineering Journal, 12(1), 317-326.
  8. Pilbala, A., Sajjadi, M., & Shafai Bajestan, M. (2018). Laboratory study of current energy dissipation passing through a rectangular LOPAC gate under submerged flow conditions. in: Proceeding of International Conference on Civil Engineering, Architecture and Urban Development Management in Iran.TEHRAN. University of Tehran. (In Persian)
  9. Sajjadi, M., Neysi, M., & Shafai Bajestan, M. (2021). Experimental Investigation of Hydraulic Conditions of Elliptical and Rectangular Lopac Gate in Free Flow Conditions, Iranian Water Research Journal, 14(39), 1-8. (In Persian).
  10. Yousofvand, F., Monem, M.J., & Kavianpour, M.R. (2015). Experimental and Theoretical Analysis of Discharge Coefficient for Submerged Lopac Gate. Irrigation and Drainage, 9(5), 811-819. (In Persian)