Simulation of Flow in Circular Clarifiers with and without Swirl
Publication: Journal of Hydraulic Engineering
Volume 120, Issue 1
Abstract
Axisymmetric numerical simulation with a finite‐volume method and the turbulence model is described for the flow in a circular model settling tank with and without swirl. The geometry of the model tank requires the use of a nonorthogonal boundary fitted grid. Results are compared with experimentally determined streamlines and flow‐through curves as well as with previous computations. For flow without swirl, the numerical simulations are in good agreement with the experimental data, and significant improvement for a critical geometrical configuration was achieved by use of the low‐diffusive HLPA discretization scheme for convection. The inclusion of swirl allows the model to account for the influence of the circumferential removal procedure as well as for the effect of swirl inducing vanes at the inlet. The simplification introduced in modeling the removal equipment impairs somewhat the accuracy of the predicted flow‐through curves. For further improvement, a more realistic and detailed modeling of the swirl momentum and turbulence production by the removal equipment is required, and complete 3‐D modeling may be needed.
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References
1.
Adams, E. W., and Rodi, W. (1988). “Prediction of density‐driven flows in settling basins.” Report SFB 210/T/41, Univ. of Karlsruhe, Karlsruhe, Germany.
2.
Adams, E. W., and Rodi, W. (1990). “Modeling flow and mixing in sedimentation tanks.” J. Hydr. Engrg., ASCE, 116(7), 895–913.
3.
Celik, I., and Rodi, W. (1985). “Simulation of hydrodynamic and transport characteristics of rectangular settling tanks.” Euromech 192, Transport of Suspended Solids in Open Channels, 129–132, Neubiberg, Germany.
4.
Courant, R., Isaacson, E., and Rees, M. (1952). “On the solution of nonlinear hyperbolic differential equations by finite differences.” Communications in Pure and Applied Mathematics, 5, 243–255.
5.
DeVantier, B. A., and Larock, B. E. (1987). “Modeling sediment‐induced density currents in sedimentation basins.” J. Hydr. Engrg., ASCE, 113(1), 80–94.
6.
Fletcher, C. A. J. (1988). Computational techniques for fluid dynamics; volume I. Springer‐Verlag, Berlin, New York, N.Y.
7.
Gaskell, P. H., and Lau, A. K. C. (1988). “Curvature‐compensated convective transport: SMART, a new boundedness‐preserving transport algorithm.” Int. J. Numer. Methods Fluids, 8, 617–641.
8.
Imam, E., McCorquodale, J. A., and Bewtra, J. K. (1983). “Numerical modeling of sedimentation tanks.” J. Hydr. Engrg., ASCE, 109(12), 1740–1754.
9.
Krebs, P. (1991). “The hydraulics of final settling tanks.” Water Sci. Technol., 23(4–6), 1037–1046.
10.
Launder, B. E., and Spalding, D. B. (1974). “The numerical computation of turbulent flows.” Comput. Meths. Appl. Mech. Eng., 2, 207–209.
11.
Leonard, B. P. (1979). “A stable and accurate convective modelling procedure based on quadratic interpolation.” Comput. Methods Appl. Mech. Engrg., 19, 59–98.
12.
Lyn, D. A., Stamou, A. I., and Rodi, W. (1992). “Density currents and shear‐induced flocculation in sedimentation tanks.” J. Hydr. Engrg., ASCE, 118(6), 849–867.
13.
Lyn, D. A., and Zhang, Z. (1989). “Boundary‐fitted numerical modelling of sedimentation tanks.” Proc. 23. IAHR Congress, A331–A338, Madrid, Spain.
14.
Majumdar, S. (1986). “Development of a finite volume procedure for prediction of fluid flow problems with complex irregular boundaries.” Report SFB 210/T/29, Univ. of Karlsruhe, Karlsruhe, Germany.
15.
Majumdar, S., Rodi, W., and Zhu, J. (1992). “Three dimensional finite‐volume method for incompressible flows with complex boundaries.” J. Fluids Engrg., Trans. ASME, 114(4), 496–503.
16.
McCorquodale, J. A. (1976). Hydraulic study of the circular settling tanks at the West Windsor pollution control plant. University of Windsor, Windsor, Canada.
17.
Rhie, C. M., and Chow, W. L. (1983). “Numerical study of the turbulent flow past an isolated airfoil with trailing edge separation.” AIAA J., 21, 1525–1532.
18.
Rodi, W. (1980). Turbulence models and their applications in hydraulics—a state of the art review. IAHR, Delft, The Netherlands.
19.
Schamber, D. R., and Larock, B. E. (1981). “Numerical analysis of flow in sedimentation basins.” J. Hydr. Div., ASCE, 107(5), 575–591.
20.
Spalding, D. B. (1972). “A novel finite‐difference formulation for differential expressions involving both first and second derivatives.” Int. J. Numer. Methods Engrg., 4, 551–559.
21.
Stamou, A. I., Adams, E. W., and Rodi, W. (1989). “Numerical modeling of flow and settling in primary rectangular clarifiers.” J. Hydraul. Res., IAHR, 27(5), 665–682.
22.
Van Doormaal, J. P., and Raithby, G. D. (1984). “Enhancements of the SIMPLE method for predicting incompressible fluid flows.” Numer. Heat Transfer Int. J. Comput. Methodol. Part A Appl., 7, 147–163.
23.
Zhou, S., and McCorquodale, J. A. (1992). “Modeling of rectangular settling tanks.” J. Hydr. Engrg., ASCE, 118(10), 1391–1405.
24.
Zhu, J. (1991a). “FAST‐2D: a computer program for numerical simulation of two‐dimensional incompressible flows with complex boundaries.” Report, Inst. for Hydromechanics, Univ. of Karlsruhe, Karlsruhe, Germany.
25.
Zhu, J. (1991b). “A low‐diffusive and oscillation‐free convection scheme.” Comm. Appl. Numer. Methods, 7, 225–232.
Information & Authors
Information
Published In
Journal of Hydraulic Engineering
Volume 120 • Issue 1 • January 1994
Pages: 4 - 21
Copyright
Copyright © 1994 American Society of Civil Engineers.
History
Received: Nov 23, 1992
Published online: Jan 1, 1994
Published in print: Jan 1994
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