Abstract
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.
Similar content being viewed by others
References
Denny, D.F.: An experimental study of air-entraining vortices in pump sumps. Proc. Inst. Mech. Eng. 170(1), 106–125 (1956)
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)
Anwar, H.O.; Weller, J.A.; Amphlett, M.B.: Similarity of free-vortex at horizontal intake. J. Hydraul. Res. 16(2), 95–105 (1987)
Gulliver, J.S.; Rindels, A.J.: Weak vortices at vertical intakes. J. Hydraul. Eng. ASCE 113(9), 1101–1116 (1987)
Hite, J.E.; Mih, W.C.: Velocity of air-core vortices at hydraulic intakes. J. Hydraul. Eng. ASCE 120(3), 284–297 (1994)
Jain, A.K.; Rangaraju, K.G.; Garde, R.J.: Vortex formation at vertical pipe intakes. J. Hydraul. Div. ASCE 104(10), 1429–1448 (1978)
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)
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)
Tastan, K.: Scale and flow boundary effects for air-entraining vortices. Water Manag. 170(4), 1–9 (2016)
Shemsi, R.; Kabiri-Samani, A.: Swirling flow at vertical shaft spillways with circular piano-key inlets. J. Hydraul. Res. 55(2), 248–258 (2017)
Tastan, K.; Yildirim, N.: Effects of intake geometry on the occurrence of a free-surface vortex. J. Hydraul. Eng. 144(4), 04018009 (2018)
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)
Rankine, W.J.M.: A Manual of Applied Mechanics. Charles Griffin, London (1858)
Burgers, J.M.: A mathematical model illustrating the theory of turbulence. Adv. Appl. Mech. 1, 171–199 (1948)
Rott, N.: On the viscous core of a line vortex. Z. Angew. Math. Phys. 9b, 543–553 (1958)
Odgaard, A.J.: Free-surface air core vortex. J. Hydraul. Eng. ASCE 112(7), 610–620 (1986)
Mih, W.C.: Analysis of fine particle concentrations in a combined vortex. J. Hydraul. Res. 28(3), 392–396 (1990)
Wang, Y.K.; Jiang, C.B.; Liang, D.F.: Comparison between empirical formulae of intake vortices. J. Hydraul. Res. 49(1), 113–116 (2011)
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)
Li, H.; Chen, H.; Zheng, M.A.; Zhou, Y.: Experimental and numerical investigation of free surface vortex. J. Hydrodyn. 20(4), 485–491 (2008)
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)
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)
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)
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)
Möller, G.: Vortex-induced air entrainment rate at intakes. Dissertation, Eidgenössische Technische Hochschule ETH Zürich. Nr. 21277 (2013)
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)
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Naderi, V., Farsadizadeh, D., Lin, C. et al. A 3D Study of an Air-Core Vortex Using HSPIV and Flow Visualization. Arab J Sci Eng 44, 8573–8584 (2019). https://doi.org/10.1007/s13369-019-03764-3
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s13369-019-03764-3