• Kim, Young-han (Department of Civil Engineering, Seoul National University) ;
  • Seo, Il-Won (Department of Civil Engineering, Seoul National University) ;
  • Ahn, Jung-kyu (Department of Civil Engineering, Seoul National University)
  • Published : 2001.01.01


In this study, laboratory experiments were performed to investigate the flow characteristics of a two-dimensional neutrally buoyant jet in the inlet region of a rectangular laboratory settling tank. Velocity measurements were made with a three-component ADV. Two types of baffles were installed in front of two-dimensional slot; a one-sided and a two-sided baffle. The flow fields from a plane jet impinging on these two types of baffles and a plane jet without a baffle showed quite different characteristics. To concentrate on investigating these flow characteristics, the effects of density currents due to temperature difference or the presence of sediments were not studied. Results of the experiments reveal that the use of the two-sided baffle results in the shortest inlet region. Also shown is that, in addition to the types of baffles, the Froude number turns out to be an important factor in the extent of the inlet region.



  1. Anderson, N. E. (1945), 'Design of settling tanks for activated sludge,' Sewage Works Journal, Vol. 17, No. 1, pp. 50-63
  2. Hazen, A. (1904), 'On sedimentation, Transactions,' ASCE, Vol. 53, pp. 45-71
  3. Krebs, P., Vischer, D. and Gujer, W. (1995). 'Inlet-Structure design for final clarifiers,' Journal of Envionmental Engineering, ASCE, Vol. 121, No. 8, pp. 558-564 https://doi.org/10.1061/(ASCE)0733-9372(1995)121:8(558)
  4. Krebs, P., Armbruster, M. and Rodi, W. (1998). 'Laboratory experiments of buoyancy-influenced flow in clarifiers,' Journal of Hyperaulic Research, Vol. 36, No. 5, pp. 831-851
  5. Lyn, D. A. and Rodi, W. (1989), 'Turbulence measurement in model settling tank,' Journal of Hydraulic Engineering, ASCE Vol. 116, No. 1, pp. 3-21
  6. Raju, K. G. R., Kothyari, U. C. and Saxena, M. (1999). 'Sediment removal efficiency of settling basins,' Journal of Irrigation and Drainage Engineering, ASCE, Vol. 125, No. 5, pp. 308-314 https://doi.org/10.1061/(ASCE)0733-9437(1999)125:5(308)