Influence of Ditch Width and Depth on Velocity Distribution in Irrigation Canals: A Case Study Using ANSYS Fluent
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Keywords:
Open Channel Flow, Ditch Geometry, ANSYS Fluent, CFD Simulation, VOF MethodAbstract
With an emphasis on a section of the Abbasia Canal in southern Punjab, Pakistan, this study
investigates how ditch width and depth affect flow behaviour in organized irrigation canals. Three distinct
ditch shapes were assessed using Computational Fluid Dynamics (CFD) modelling in ANSYS Fluent to
see how they affected energy dissipation, turbulence intensity, and velocity distribution. The realizable k-ε
turbulence model was utilized to simulate flow structures and energy losses, while the Volume of Fluid
(VOF) approach was utilized to capture free surface flow behaviour. In order to replicate real-world field
circumstances, each simulation included a perpendicular ditch that was attached to the main canal and
varied in size. The findings show that ditch shape affects hydraulic efficiency by substantially changing
both longitudinal and lateral velocity profiles. With its consistent velocity distribution and low turbulence,
the configuration in Case 2 (3 m broad, 0.75 m deep) showed the best performance, increasing discharge
capacity. However, Case 3 (6 m wide, 1.5 m deep) increased the possibility for sediment deposition and
decreased flow momentum while successfully lowering peak flow velocities and wasted energy. A
moderate balance between these impacts was provided by Case 1. In addition to offering practical advice
for maximizing water delivery, reducing erosion, and promoting sustainable canal infrastructure in semi
arid areas, these findings highlight the significance of ditch design in irrigation canal management.
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