The KSFM Journal of Fluid Machinery (한국유체기계학회 논문집)

Korean Society for Fluid machinery (한국유체기계학회)
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Numerical Study on Flow Patterns in a Stirred Tank with Impeller Types

혼합탱크 내의 임펠라 형태에 따른 유동 특성에 관한 수치해석

  • Published : 2002.06.01
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Abstract

The present study is concerned with the flow patterns induced by various impellers in a rectangular tank. Impellers are FBT (Flat blade turbine), PBT (Pitched blade turbine), Shroud turbine, Rushton turbine, and Helical ribbon turbine types. The solutions of flows in moving reference frames require the use of 'moving' cell zone. The moving zone approaches are based on MRF (Multiple reference frame), which is a steady-state approximation and sliding method, which is an unsteady-state approximation. Numerical results using two moving zone approaches we compared with experiments by Ranade & Joshi, which have done extensive LDA measurements of the flow generated by a standard six-bladed Rushton turbine in a cylindrical baffled vessel. In this paper, we simulated the flow patterns with above-mentioned moving zone approaches and impellers. Turbulence model used is RNG $k-{\epsilon}$ model. Sliding-mesh method is more effective than MRF for simulating the rectangular tank with inlet and outlet. RNG $k-{\epsilon}$ model strongly underestimates the velocity of experimental data and velocity by Chen & Kim's model, but it seems to be correctly predicted in overall distribution.

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References

  1. Kawamura, S., 1997, Integrated Design of Water Treatment Facilities. John Wiley & Sons, INC., New York. pp. 97-129.
  2. Amirtharajah, A., Clack, M.M. & Trussell, R,.R., 1991, Mixing in Coagulation and Flocculation, American Water Works Association, pp, 282-342.
  3. 尹雲榮, 1993, 임펠라의 類型이 高粘度 液體의 混合에 미치는 影響, 成均館大學敎, 碩士學位論文.
  4. Deen, N.G., Hjertager, B.H. 1999, Multiphase Particle Image Velocimetry Measurements in an Aerated Stirred Tank, Aalborg University Esbjerg, pp. 1-15.
  5. Friberg, P.C., 1998, Three-Dimensional Modeling of Gas/Liquid Flow Processes in Bioreactors, Group for Industrial Fluid Flow Processes, Telemark University College, Norway, pp. 1-100.
  6. Ranade, V.V., Joshi. J.B., 1990, "Flow Generated by a Disc Turbine: Part I," Experimental Trans. IChemE, pp. 19-33.
  7. Fluent 5-User's Guide, 1998, Fluent Inc., Lebanon, Vol. 3, pp. 16.1-16.52.
  8. Versteeg, H.K., Malalasekera, W., 1995, An Introduction to Computational Fluid Dynamics-The Finite Volume Method, LONGMAN, London, pp. 10-39.
  9. Drury, S.F., Gates, L.E., Sharpe, P.E., 1999, The Application of Mixing and Agitation to Fluid Processes, Sharpe Mixer Q1 Technology, pp. 1-57.