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Journal of Hydrodynamics

, Volume 30, Issue 4, pp 715–721 | Cite as

Transient air-water flow patterns in the vent tube in hydropower tailrace system simulated by 1-D-3-D coupling method

  • Xi-chen Wang (王希晨)
  • Jian Zhang (张健)
  • Xiao-dong Yu (俞晓东)
  • Sheng Chen (陈胜)
Articles
  • 27 Downloads

Abstract

The vent tube is commonly used for the water hammer protection in the hydropower tailrace system. In transient processes, with air entering and exiting the vent tube, one sees complex hydraulic phenomena, which threaten the station’s safe operation. It is necessary to investigate the transient mechanisms in the tailrace system with vent tube. In this paper, a 3-D, two-phase numerical model of a vent tube on the connection of the tailrace tunnel and the diversion tunnel, is developed based on the FLUENT with the volume of fluid (VOF) algorithm to investigate the transient air-water flow patterns and the complex hydraulic phenomena in the vent tube of the tailrace system. A 1-D and 3-D unidirectional adjacent coupling (1-D-3-D-UAC) approach with a linear interpolation method is adopted to adjust the timesteps between the 1-D model and the 3-D model on the tunnel inlet and outlet boundaries through the user defined function (UDF), to transmit the data from the 1-D model to the 3-D model. The model is verified by comparing the results obtained by using the 1-D model alone and from the experiments in literature. The transient flow processes under the full load rejection consist of four stages: the water level dropping stage, the air entering stage, the air pocket collapsing stage, and the air exiting stage. Detailed hydraulic phenomena in the air pocket collapsing process are also discussed.

Key words

Vent tube tailrace tunnel two phase volume of fluid (VOF) 1-D-3-D coupling 

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References

  1. [1]
    Yu X., Zhang J. Investigation on hydraulic transients in tailrace tunnel with air inlet and release from the vent [J]. Journal of Hydraulic Engineering, 2016, 47(8): 1045–1053(in Chinese).Google Scholar
  2. [2]
    Zhang W., Cai F., Zhou J. et al. Experimental investigation on air-water interaction in a hydropower station combining a diversion tunnel with a tailrace tunnel [J]. Water, 2017, 9(4): DOI: 10.33901w9040274.Google Scholar
  3. [3]
    Zhang Z., Hua Y., Cheng H. Numerical simulation of free surface-pressurized flow in tailrace tunnel transformed from diversion tunnel [J]. Yellow River, 2015, 37(4): 105–108(in Chinese).Google Scholar
  4. [4]
    Yang K., Guo Y., Fu H. et al. Modelling similarity laws for pipe water-filled transients [J], Journal of Hydraulic Engineering, 2012, 43(10): 1188–1193(in Chinese).Google Scholar
  5. [5]
    Zhang J., Suo L. Study on tailrace surge chamber installation and hydraulic transients at pumped-storage plant [J]. Water Resources and Power, 2008, 26(3): 83–87.Google Scholar
  6. [6]
    Yu X., Zhang J., Fan C. et al. Stability analysis of governor-turbine-hydraulic system by state space method and graph theory [J]. Energy, 2016, 114: 613–622.CrossRefGoogle Scholar
  7. [7]
    Avdyushenko A. Y., Cherny S. G., Chirkov D. V. et al. Numerical simulation of transient processes in hydroturbines [J]. Thermophysics and Aeromechanics, 2013, 20(5): 577–593.CrossRefGoogle Scholar
  8. [8]
    Liu M., Cai F., Zhang W. et al. The impact of air vent on free-surface-pressurized flow in tailrace tunnels [J]. China Rural Water and Hydropower, 2014, (2): 150–152, 156(in Chinese).Google Scholar
  9. [9]
    Cai F., Cheng Y. G., Xia L. S. et al. Mechanism of air-trapped vertical vortices in long-corridor-shaped surge tank of hydropower station and their elimination [J]. Journal of Hydrodynamics, 2017, 29(5): 845–853.CrossRefGoogle Scholar
  10. [10]
    Chen Y., Wu C., Wang B. et al. Three-dimensional numerical simulation of vertical vortex at hydraulic intake [J]. Procedia Engineering, 2012, 28: 55–60.CrossRefGoogle Scholar
  11. [11]
    El-shaikh A. G. CFD technique for solving low water level problem of axial flow pumps [J]. American Journal of Water Science and Engineering, 2017, 3(3): 34–44.CrossRefGoogle Scholar
  12. [12]
    Ljubijankic M., Nytsch-geusen C., Rädler J. et al. Numerical coupling of Modelica and CFD for building energy supply systems [C]. The 8th International Modelica Conference, Dresden, Germany, 2011, 286–294.Google Scholar
  13. [13]
    Nobile F. Coupling strategies for the numerical simulation of blood flow in deformable arteries by 3D and 1D models [J]. Mathematical and Computer Modelling, 2009, 49(11–12): 2152–2160.MathSciNetCrossRefzbMATHGoogle Scholar
  14. [14]
    Galindo J., Tiseira A., Fajardo P. et al. Coupling methodology of 1D finite difference and 3D finite volume CFD codes based on the method of characteristics [J]. Mathematical and Computer Modelling, 2011, 54(7–8): 1738–1746.MathSciNetCrossRefzbMATHGoogle Scholar
  15. [15]
    Wang C., Nilsson H., Yang J. et al. 1D–3D coupling for hydraulic system transient simulations [J]. Computer Physics Communications, 2017, 210: 1–9.MathSciNetCrossRefzbMATHGoogle Scholar
  16. [16]
    Zhang X., Cheng Y. Simulation of hydraulic transients in hydropower system using the 1D–3D coupling approach [J]. Journal of Hydrodynamics, 2012, 24(4): 595–604.CrossRefGoogle Scholar
  17. [17]
    Wu D., Yang S., Wu P. et al. MOC-CFD coupled approach for the analysis of the fluid dynamic interaction between water hammer and pump [J]. Journal of Hydraulic Engineering, ASCE, 2015, 141(6): 06015003.CrossRefGoogle Scholar
  18. [18]
    ANSYS Inc. ANSYS FLUENT 14.5 theory guide [M]. Canonsburg, Pennsylvania, USA: ANSYS Inc., 2012.Google Scholar
  19. [19]
    Wright S. J., Lewis J. W., Vasconcelos J. G. Geysering in rapidly filling storm-water tunnels [J]. Journal of Hydraulic Engineering, ASCE, 2010, 137(1): 112–115.CrossRefGoogle Scholar
  20. [20]
    Muller K., Vasconcelos J. G. Large-scale testing of storm water geysers caused by the sudden release of air pockets–preliminary research findings [C]. World Environmental and Water Resources Congress, Sacramento, California, USA, 2016, 442–451.Google Scholar
  21. [21]
    Muller K. Z., Wang J., Vasconcelos J. G. et al. Water displacement in shafts and geysering created by uncontrolled air pocket releases [J]. Journal of Hydraulic Engineering, ASCE, 2017, 143(10): DOI: 10.1061/(ASCE) HY.1943-7900.0001362.Google Scholar

Copyright information

© China Ship Scientific Research Center 2018

Authors and Affiliations

  • Xi-chen Wang (王希晨)
    • 1
  • Jian Zhang (张健)
    • 1
  • Xiao-dong Yu (俞晓东)
    • 1
  • Sheng Chen (陈胜)
    • 1
  1. 1.College of Water Conservancy and Hydropower EngineeringHohai UniversityNanjingChina

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