Skip to main content

Advertisement

Log in

Three-dimensional flow visualization in the wake of a miniature axial-flow hydrokinetic turbine

  • Research Article
  • Published:
Experiments in Fluids Aims and scope Submit manuscript

Abstract

Three-dimensional 3-component velocity measurements were made in the near wake region of a miniature 3-blade axial-flow turbine within a turbulent boundary layer. The model turbine was placed in an open channel flow and operated under subcritical conditions (Fr = 0.13). The spatial distribution of the basic flow statistics was obtained at various locations to render insights into the spatial features of the wake. Instantaneous and phase-averaged vortical structures were analyzed to get insights about their dynamics. The results showed a wake expansion proportional to the one-third power of the streamwise distance, within the first rotor diameter. Wake rotation was clearly identified up to a distance of roughly three rotor diameters. In particular, relatively high tangential velocity was observed near the wake core, but it was found to be nearly negligible at the turbine tip radius. In contrast, the radial velocity showed the opposite distribution, with higher radial velocity near the turbine tip and, due to symmetry, negligible at the rotor axis. Larger turbulence intensity was found above the hub height and near the turbine tip. Strong coherent tip vortices, visualized in terms of the instantaneous vorticity and the λ 2 criterion, were observed within the first rotor diameter downstream of the turbine. These structures, influenced by the velocity gradient in the boundary layer, appeared to loose their stability at distances greater than two rotor diameters. Hub vortices were also identified. Measurements did not exhibit significant tip–hub vortex interaction within the first rotor diameter.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12
Fig. 13
Fig. 14
Fig. 15
Fig. 16
Fig. 17

Similar content being viewed by others

References

  • Bahaj AS, Molland AF, Chaplin JR, Batten WMJ (2007) Power and thrust measurements of marine current turbines under various hydronamic flow conditions in a cavitation tunnel and a towing tank. Renew Energy 32:407–426

    Article  Google Scholar 

  • Chamorro LP, Arndt REA, Sotiropoulos F (2012) Reynolds number dependence of turbulence statistics in the wake of wind turbines. Wind Energy 15:733–742

    Article  Google Scholar 

  • Chamorro LP, Porté-Agel F (2009) A wind-tunnel investigation of wind-turbine wakes: boundary-layer turbulence effects. Boundary Layer Meteorol 132:129–149

    Article  Google Scholar 

  • Felli M, Camussi R, Di Felice F (2011) Mechanisms of evolution of the propeller wake in the transition and far fields. J Fluid Mech 682:5–53

    Article  MATH  Google Scholar 

  • Flammang B, Lauder G, Troolin D, Strand T (2011) Volumetric imaging of shark tail hydrodynamics reveals a three-dimensional dual-ring vortex wake structure. In: Proceedings of the Royal Society of London B. doi:10.1098/rspb.2011.0489

  • Jeong J, Hussain F (1995) On the identification of a vortex. J Fluid Mech 285:69–94

    Article  MathSciNet  MATH  Google Scholar 

  • Kang S, Borazjani I, Colby J, Sotiropoulos F (2012) Numerical simulation of 3d flow past a real-life marine hydrokinetic turbine. Adv Water Res 39:33–43

    Article  Google Scholar 

  • Khan M, Bhuyan G, Iqbal M, Quaicoe J (2009) Hydrokinetic energy conversion systems and assessment of horizontal and vertical axis turbines for river and tidal applications: a technology status review. Appl Energy 86:1823–1835

    Article  Google Scholar 

  • Lange C (2003) Harnessing tidal energy takes new turn: could the application of the windmill principle produce a sea change? IEEE Spect. http://spectrum.ieee.org/green-tech/geothermal-and-tidal/harnessing-tidal-energy-takes-new-turn

  • Le T, Borazjani I, Kang S, Sotiropoulos F (2011) On the structure of vortex rings from inclined nozzles. J Fluid Mech 686:451–483

    Article  MATH  Google Scholar 

  • Maganga F, Germain G, King J, Pinon G, Rivoalen E (2010) Experimental characterisation of flow effects on marine current turine behaviour and on its wake properties. IET Renew Power Gener 4(6):498–509

    Article  Google Scholar 

  • Meyer J, Feller W (1975) Development of a controllable particle generator for lv seeding in hypersonic wind tunnels. Minnesota Symp on Laser Anemometry, p 345

  • Molland AF, Bajah AS, Batten WMJ, Chaplin JR (2004) Measurements and predictions of forces, pressures and cavitation on 2-d sections suitable for marine current turbines. J Eng Maritime Environ 218:127–138

    Google Scholar 

  • Okulov V, Sorensen J (2007) Stability of helical tip vortices in a rotor far wake. J Fluid Mech 576:1–25

    Article  MathSciNet  MATH  Google Scholar 

  • Papaconstantinou A, Bergeles G (1988) Hot-wire measurements of the flowfield in the vicinity of a hawg rotor. J Wind Eng Ind Aerodyn 31:133–146

    Article  Google Scholar 

  • Pereira F, Gharib M (2002) Defocusing digital particle image velocimetry and the three-dimensional characterization of two-phase flows. Meas Sci Tech 13:683–694

    Article  Google Scholar 

  • Pereira F, Gharib M, Dabiri D, Modarress D (2000) Defocusing digital particle image velocimetry: a 3-component 3-dimensional dpiv measurement technique. Application to bubbly flows. Exp Fluids 29:S078–S084

    Article  Google Scholar 

  • Pereira F, Stuer H, Graff E, Gharib M (2006) Two-frame 3d particle tracking. Meas Sci Tech 17:1680–1692

    Article  Google Scholar 

  • Pierson SH (2009) Composite rotor design for a hydrokinetic turbine. University of Tennessee Honors Thesis Projects. http://trace.tennessee.edu/utk_chanhonoproj/1311

  • Schlichting H (1979) Boundary layer theory. McGraw-Hill Book Company, New York

    MATH  Google Scholar 

  • Sharp K, Hill D, Troolin D, Walters G, Lai W (2010) Volumetric 3-component velocimetry measurements of the turbulent flow around a rushton turbine. Exp Fluids 48(1):167–183

    Article  Google Scholar 

  • Tom K (2010) Investigation of near wake flow structure of a horizontal axis wind turbine using particle image velocimetry. M.Sc Thesis, Concordia University

  • Troolin D, Longmire E (2009) Volumetric velocity measurements of vortex rings from inclined exits. Exp Fluids 48(3):409–420

    Article  Google Scholar 

  • Wang D, Atlar M, Sampson R (2007) An experimental investigation on cavitation, noise, and slipstream characteristics of ocean stream turbines. J Power Energy 221:219–231

    Article  Google Scholar 

Download references

Acknowledgments

Funding was provided by Advanced Water Power Project (Grant No. DE-FG36-08GO18168/M001) and supported by Verdant Power, Department of Energy DOE (DE-EE0002980), and Xcel Energy through the Renewable Development Fund (grant RD3-42). The authors gratefully acknowledge the assistance of Prof. Fernando Porté-Agel during the first stage of the experiments.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Leonardo P. Chamorro.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Chamorro, L.P., Troolin, D.R., Lee, SJ. et al. Three-dimensional flow visualization in the wake of a miniature axial-flow hydrokinetic turbine. Exp Fluids 54, 1459 (2013). https://doi.org/10.1007/s00348-013-1459-9

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1007/s00348-013-1459-9

Keywords

Navigation