Investigation on flow field near confluence of two rigid channels at zero-degree

Confluence is common occurrence in both natural and manmade open channels. In present study, flow field near the confluence of zero-degree open channels are investigated. Experiments were performed in the laboratory for the different discharge ratios, and the three-dimensional velocities were measured with the help of ADV. Velocity data obtained from experimental measurements were utilized to validate the numerical results. Computational Fluid Dynamics based Detached Eddy Simulations (DES) numerical model was used to obtain flow field near the confluence of the channels. Effect of discharge ratio on the flow field was studied. Flow field showed presence of vortices close to the confluence when the discharge ratio was 1.0. These vortices pose a potential risk to the confluence system. However, with the decrease in the discharge ratio the formation of vortices moves downstream of the confluence. The numerical model used in the study established good agreement with experimental data. This suggests that the numerical simulations accurately captured the behaviour of the flow field.