Water and Irrigation Management

Water and Irrigation Management

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

Document Type : Research Paper

Authors
Faranak Mobarak 1
seyed mohsen sajjadi 2
Javad Ahadiyan 3
Mehdi Zeynivand 2
1 Master of Hydraulic Structures, Department of Water Structures, Faculty of Water and Environmental Engineering, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
2 Assistant Professor, Department of Water Structures, Faculty of Water and Environmental Engineering, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
3 Associate Professor, Department of Water Structures, Faculty of Water and Environmental Engineering, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
10.22059/jwim.2022.335817.952
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
Elliptical ratio
Energy consumption
Flow3d
Opening
Shear stress
Sudden transition
Subjects
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Water and Irrigation Management
Volume 12, Issue 2
Summer 2022
Pages 263-275