Investigating the effect of Inlet and Outlet location on Flow field and Sedimentation pattern of a rectangular settling basin using CCHE2D

Abstract

Water obtained from any source may contain impurities induced by erosion, dissolved minerals, dissolved gases and material produced from organic matter decomposing. If the amount of these substances exceed a certain limit, not only the water would not be potable, but the water containing the material will not be suitable to be used in most applications, or at least before treatment cannot be applied in everyday use. Sediment particles separation from flow via gravity in settling tanks and basins is one of the effective solutions in water treatment, urban water delivery projects and prevention of sediment entrance into irrigation networks. Construction cost of a settling basin is about one third of the total expenditure involved in constructing a water treatment plant. So a great economy may be achieved by increasing settling efficiency. Herein this paper by applying CCHE2D numerical model, the effect of geometric parameters such as inlet and outlet locations on flow field and sedimentation pattern in a rectangular settling basin is investigated. Results show that some variations in flow field and eddies formation and hence, sedimentation pattern takes place in the basin. Results also confirm that the model could appropriately simulate flow field and sedimentation pattern with a reasonable error percentage.