A 3D Study of an Air-Core Vortex Using HSPIV and Flow Visualization

  • Vadoud NaderiEmail author
  • Davood Farsadizadeh
  • Chang Lin
  • Susan Gaskin
Research Article - Civil Engineering


A free-surface vortex is a mass of water rotating around an axis perpendicular to the free surface. It can occur when withdrawing water from reservoirs or rivers at hydropower intakes with low submergence. Existing vortex models provide general information about the symmetric vortex structure. The vortex structure occurring in an approach flow at the critical submergence condition is examined in detail. In the laboratory, a steady air-core vortex over a bottom intake was created in a wide recirculating flume, in which the water depth, mean velocity of the approach flow and intake discharge could be adjusted. Flow visualization shows that the approach flow results in a non-symmetrical velocity distribution in the vortex throughout the flow depth. The detailed set of high-speed particle image velocimetry data in a series of horizontal and vertical planes was used to observe the formation and evolution of the three-dimensional flow structure of the strong air-core vortex and determine the origin of the vortex. Analysis of these data revealed a complex three-dimensional vortex structure due to the approach flow interacting with the air-core vortex forming a secondary vortex originating at the mixing zone upstream of the vortex, identified by a zero downstream velocity component, and feeding into the upstream side of the intake.


Vortex structure Asymmetric vortex Bottom intake HSPIV Flow visualization Vortex origin 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Denny, D.F.: An experimental study of air-entraining vortices in pump sumps. Proc. Inst. Mech. Eng. 170(1), 106–125 (1956)Google Scholar
  2. 2.
    Hecker, G.E.: Fundamentals of vortex intake flow. Conclusions, [chapters 2 and 8]. In: Knauss, J. (ed.) Swirling Flow Problems at Intakes. IAHR Hydraulic Structures Design Manual. Balkema, Rotterdam (1987)Google Scholar
  3. 3.
    Anwar, H.O.; Weller, J.A.; Amphlett, M.B.: Similarity of free-vortex at horizontal intake. J. Hydraul. Res. 16(2), 95–105 (1987)Google Scholar
  4. 4.
    Gulliver, J.S.; Rindels, A.J.: Weak vortices at vertical intakes. J. Hydraul. Eng. ASCE 113(9), 1101–1116 (1987)Google Scholar
  5. 5.
    Hite, J.E.; Mih, W.C.: Velocity of air-core vortices at hydraulic intakes. J. Hydraul. Eng. ASCE 120(3), 284–297 (1994)Google Scholar
  6. 6.
    Jain, A.K.; Rangaraju, K.G.; Garde, R.J.: Vortex formation at vertical pipe intakes. J. Hydraul. Div. ASCE 104(10), 1429–1448 (1978)Google Scholar
  7. 7.
    Borghei, S.M.; Kabiri-Samani, A.R.: Effect of anti-vortex plates on critical submergence at a vertical intake. Sci. Iran. 17(2), 89–95 (2010)Google Scholar
  8. 8.
    Naderi, V.; Farsadizadeh, D.; Hosseinzadeh-Dalir, A.; Arvanaghi, H.: Experimental study of bell-mouth intakes on discharge coefficient. J. Civil Eng. Urban. 3(6), 368–371 (2013)Google Scholar
  9. 9.
    Tastan, K.: Scale and flow boundary effects for air-entraining vortices. Water Manag. 170(4), 1–9 (2016)MathSciNetGoogle Scholar
  10. 10.
    Shemsi, R.; Kabiri-Samani, A.: Swirling flow at vertical shaft spillways with circular piano-key inlets. J. Hydraul. Res. 55(2), 248–258 (2017)Google Scholar
  11. 11.
    Tastan, K.; Yildirim, N.: Effects of intake geometry on the occurrence of a free-surface vortex. J. Hydraul. Eng. 144(4), 04018009 (2018)Google Scholar
  12. 12.
    Gao, X.; Zhang, H.; Liu, J.; Sun, B.; Tian, Y.: Numerical investigation of flow in a vertical pipe inlet/outlet with a horizontal anti-vortex plate: effect of diversion orifices height and divergence angle. Eng. Appl. Comput. Fluid Mech. 12(1), 182–194 (2018)Google Scholar
  13. 13.
    Rankine, W.J.M.: A Manual of Applied Mechanics. Charles Griffin, London (1858)zbMATHGoogle Scholar
  14. 14.
    Burgers, J.M.: A mathematical model illustrating the theory of turbulence. Adv. Appl. Mech. 1, 171–199 (1948)MathSciNetGoogle Scholar
  15. 15.
    Rott, N.: On the viscous core of a line vortex. Z. Angew. Math. Phys. 9b, 543–553 (1958)MathSciNetzbMATHGoogle Scholar
  16. 16.
    Odgaard, A.J.: Free-surface air core vortex. J. Hydraul. Eng. ASCE 112(7), 610–620 (1986)Google Scholar
  17. 17.
    Mih, W.C.: Analysis of fine particle concentrations in a combined vortex. J. Hydraul. Res. 28(3), 392–396 (1990)Google Scholar
  18. 18.
    Wang, Y.K.; Jiang, C.B.; Liang, D.F.: Comparison between empirical formulae of intake vortices. J. Hydraul. Res. 49(1), 113–116 (2011)Google Scholar
  19. 19.
    Sarkardeh, H.; Zarrati, A.R.; Roshan, R.: Effect of intake head wall and trash rack on vortices. J. Hydraul. Res. 48(1), 108–112 (2010)Google Scholar
  20. 20.
    Li, H.; Chen, H.; Zheng, M.A.; Zhou, Y.: Experimental and numerical investigation of free surface vortex. J. Hydrodyn. 20(4), 485–491 (2008)Google Scholar
  21. 21.
    Rajendran, V.P.; Patel, V.C.: Measurement of vortices in model pump-intake bay by PIV. J. Hydraul. Eng. ASCE 126(5), 322–334 (2000)Google Scholar
  22. 22.
    Okamura, T.; Kamemoto, K.; Matsui, J.: CFD prediction and model experiment on suction vortices in pump sump. In: Proceedings of 9th Asian International Conference on Fluid Machinery, October, Jeju, South Korea, AICFM9-053 (2007)Google Scholar
  23. 23.
    Suerich-Gulick, F.; Gaskin, S.J.; Villeneuve, M.; Parkinson, E.: Characteristics of free surface vortices at low head hydropower intakes. J. Hydraul. Res. 140, 291–299 (2014a)Google Scholar
  24. 24.
    Suerich-Gulick, F.; Gaskin, S.J.; Villeneuve, M.; Parkinson, E.: Free surface intake vortices: theoretical model and measurements. J. Hydraul. Res. 52(4), 502–512 (2014b)Google Scholar
  25. 25.
    Möller, G.: Vortex-induced air entrainment rate at intakes. Dissertation, Eidgenössische Technische Hochschule ETH Zürich. Nr. 21277 (2013)Google Scholar
  26. 26.
    Mulligan, S.; Casserly, J.; Sherlock, R.: Experimental and numerical modelling of free-surface turbulent flows in full air-core water vortices. In: Gourbesville, P., Cunge, J., Caignaert, G. (eds.) Advances in Hydroinformatics, pp. 549–569. Springer WaterSpringer, Singapore (2016)Google Scholar

Copyright information

© King Fahd University of Petroleum & Minerals 2019

Authors and Affiliations

  1. 1.Department of Water Science and EngineeringUniversity of TabrizTabrizIran
  2. 2.Department of Civil EngineeringNCHUTaichungTaiwan
  3. 3.Department of Civil Engineering and Applied MechanicsMcGill UniversityMontrealCanada

Personalised recommendations