Experimental and Numerical Investigation of the Effect of Submerged Baffle on the Trap Efficiency of Settling Basin

Document Type : Research Article


Dept. of Irrigation and Reclamation Eng., University of Tehran, Karaj, Iran


The effect of a submerged normal flat plate on the trap efficiency and sedimentation length of a settling basin was experimentally investigated in this study and compared with the results of a numerical model. The implemented numerical model is an Eulerian-Lagrangian model that solves The Reynolds-Averaged Navier-Stokes equations with k¾e turbulence model for the continuous phase and sediment particles are tracked with a lagrangian method. The results indicate that, when the linear transition transmits the flow with high momentum from the upstream canal into the basin with no extra turbulence and a parallel 2D flow is established in the basin, the baffle has no positive effect on the trap efficiency and the sedimentation length.
However, in 3D conditions in which the incoming jet travels a considerable distance and causes large variations of transverse velocity in the basin, installing the baffle in a relative submergence of 15% can increase the trap efficiency of the settling basin by up to 8.5%. This may be attributed to the role of the baffle in decaying the kinetic energy of the impinging jet and spreading the sediment particles in the width of the settling basin.