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Acta Mechanica Sinica

, 27:510 | Cite as

Lattice Boltzmann simulation of flows in bifurcate channel at rotating inflow boundary conditions and resulted different outflow fluxes

  • Qing-Dong CaiEmail author
Research Paper

Abstract

The Lattice Boltzmann method (LBM) is used to simulate the flow field in a bifurcate channel which is a simplified model of the draft tube of hydraulic turbine machine. According to the simulation results, some qualitative conclusions can be deduced. The reason of uneven flux in different branches of draft tube is given. Not only the vortex rope itself, but also the attenuation of the rotation strength is important in bringing on the uneven flux. The later leads to adverse pressure gradient, and changes the velocity profile. If the outlet contains more than one exit, the one that contains the vortex rope will lose flux because of this adverse pressure gradient. Several possible methods can be used to minimize the adverse pressure gradient domain in order to improve the efficiency of turbine machine.

Keywords

Lattice Boltzmann method Hydraulic turbine machine Draft tube Vortex rope 

References

  1. 1.
    Zhang, R.K., Cai, Q.D., Wu, J.Z., et al.: The physical origin of severe lowfrequency pressure fluctuations in giant Francis turbines. Mod. Phys. Lett. B 28 & 29, 1527–1530 (2005)CrossRefGoogle Scholar
  2. 2.
    Zhang, R.K., Mao, F., Wu, J.Z., et al.: Analysis and control of part-load unsteady flow in Francis turbine’s draft tube. In: Proceedings of GT2007 ASME Turbo Expo 2007: Power for Land, Sea and Air. May 14–17, 2007, Montreal, Canada, GT2007-27440Google Scholar
  3. 3.
    Andersson, U., Jungstedt, J., Cervantes, M.J.: Model experiments of dynamic loads on a draft tube pier. In: Proceedings of the 24th IAHR Symposium on Hydraulic Machinery and Systems, Foz Do Iguassu, Brazil, Oct. 27–31, 2008Google Scholar
  4. 4.
    Zou, Q., He, X.: On pressure and velocity boundary conditions for the lattice Boltzmann BGK model. Phys. Fluids 9(6), 1591 (1997)MathSciNetzbMATHCrossRefGoogle Scholar
  5. 5.
    Nobel, D., Chen, S., Georgiadis, J., et al.: A consistent hydrodynamic boundary condition for the lattice Boltzmann method. Phys. Fluids 7(1), 203 (1995)CrossRefGoogle Scholar
  6. 6.
    Wu, J.Z., Ma, H.Y., Zhou, M.D.: Vorticity and Vortex Dynamics. Springer, Berlin, 2006CrossRefGoogle Scholar
  7. 7.
    Chen, Y., Cai, Q.D.: The Lattice Boltzmann method based on quadtree mesh. Modern Physics Letters B 23(3), 289–292 (2009)zbMATHCrossRefGoogle Scholar
  8. 8.
    Chen, Y., Xia, Z.H., Cai, Q.D.: Lattice Boltzmann method with tree structured mesh and treatment of curved boundaries. Chinese Journal of Computational Physics 27(1), 23–30 (2010) (in Chinese)Google Scholar
  9. 9.
    Liu, S.H., Wu, X.J., Wu, Y.L.: Analysis of the influence of runner-hub shape on the internal flow in francis turbine. J. Hydraul. Eng. 25(1), 67–71 (2006) (in Chinese)Google Scholar
  10. 10.
    Blommaert, G.: Étude du comportement dynamique des turbines francis: controle actif de leur stabilite de fonctionnement. [Ph.D. Thesis], École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 2000Google Scholar
  11. 11.
    Susan-Resiga, R., Vu, C.T., Muntean, S., et al.: Jet control of the draft tube vortex rope in francis turbines at partial discharge. In: Proceedings of the 23rd IAHR Symposium on Hydraulic Machinery and Systems, Yokohama, Japan, Oct. 17–21, Paper No. 192, 2006Google Scholar
  12. 12.
    Zhang, R.K., Mao, F., Wu, J.Z., et al.: Characteristics and control of the draft-tube flow in part-load francis turbine. Journal of Fluids Engineering 131, 021101 (2009)CrossRefGoogle Scholar
  13. 13.
    Wei, C.X., Han, F.Q., Chen, Z.S., et al.: The characteristic test of runner hubs for hydraulic turbine. Large Electric Machine and Hydraulic Turbine (1), 36–39 (2001) (in Chinese)Google Scholar

Copyright information

© The Chinese Society of Theoretical and Applied Mechanics; Institute of Mechanics, Chinese Academy of Sciences and Springer-Verlag Berlin Heidelberg 2011

Authors and Affiliations

  1. 1.LTCS and HEDPS, CAPT, Department of Mechanics and Aerospace Engineering, College of EngineeringPeking UniversityBeijingChina

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