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Confinement effects in wind-turbine and propeller measurements

Published online by Cambridge University Press:  01 September 2014

Antonio Segalini*
Affiliation:
Linné FLOW Centre, KTH Mechanics, S-100 44 Stockholm, Sweden
Pieter Inghels
Affiliation:
Linné FLOW Centre, KTH Mechanics, S-100 44 Stockholm, Sweden
*
Email address for correspondence: segalini@mech.kth.se

Abstract

A new model to account for the presence of the test-section wall in wind-turbine or propeller measurements is proposed. The test section, here assumed to be cylindrical, is modelled by means of axisymmetric source panels, while the wind turbine (or the propeller) is modelled with a simplified vortex model (Segalini & Alfredsson, J. Fluid Mech., vol. 725, 2013, pp. 91–116). Combining both models in an iterative scheme allows the simulation of the effect of the test-section wall on the flow field around the rotor. Based on this novel approach, an analysis of the flow modification due to blockage is conducted together with a comparison of actuator-disk theory results. Glauert’s concept of equivalent unconfined turbine is reviewed and extended to account for the angular velocity of the rotor. It is shown that Glauert’s equivalent free-stream velocity concept is beneficial and can correct most of the systematic error introduced by the presence of the test-section wall, although some discrepancies remain, especially in the power coefficient. The effect of the confinement on the wake structure is also discussed in terms of wake expansion/contraction, pitch of the tip vortices and forces at the rotor.

Type
Papers
Copyright
© 2014 Cambridge University Press 

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References

Bahaj, A. S., Molland, A. F., Chaplin, J. R. & Batten, W. M. J. 2007 Power and thrust measurements of marine current turbines under various hydrodynamic flow conditions in a cavitation tunnel and a towing tank. Renew. Energy 32, 407426.CrossRefGoogle Scholar
Barlow, J. B., Rae, W. H. & Pope, A. 1999 Low-Speed Wind Tunnel Testing, 3rd edn. John Wiley & Sons.Google Scholar
Batchelor, G. K. 1967 An Introduction to Fluid Dynamics. Cambridge University Press.Google Scholar
Burton, T., Sharpe, D., Jenkins, N. & Bossanyi, E. 2001 Wind Energy Handbook. John Wiley & Sons.Google Scholar
Callegari, A. J. & Ting, L. 1978 Motion of a curved vortex filament with decaying vortical core and axial velocity. J. Appl. Maths 35, 148175.Google Scholar
Chen, T. Y. & Liou, L. R. 2011 Blockage corrections in wind tunnel tests of small horizontal-axis wind turbines. Exp. Therm. Fluid Sci. 35, 565569.Google Scholar
Fukumoto, Y. & Miyazaki, T. 1991 Three-dimensional distortions of a vortex filament with axial velocity. J. Fluid Mech. 222, 369416.Google Scholar
Garrett, C. & Cummins, P. 2007 The efficiency of a turbine in a tidal channel. J. Fluid Mech. 588, 243251.Google Scholar
Glauert, H. 1935 Airplane propellers. In Division L in Aerodynamic Theory (ed. Durand, W. F.), vol. 4, pp. 169360. Springer.CrossRefGoogle Scholar
Goodman, T. R. 1956 The tip correction for wind-tunnel tests of propellers. J. Aeronaut. Sci. 23, 10941098.Google Scholar
Joukowsky, N. E. 1912 Vortex theory of screw propeller. I. Trudy Otdeleniya Fizicheskikh Nauk Obshchestva Lubitelei Estestvoznaniya 16 (1), 131 (in Russian). French translation in Théorie Tourbillonnaire de l’Hélice Propulsive, pp. 1–47. Gauthier-Villars, 1929.Google Scholar
Katz, J. & Plotkin, A. 1991 Low-Speed Aerodynamics: From Wing Theory to Panel Methods. McGraw-Hill.Google Scholar
Kuibin, P. A. & Okulov, V. L. 1998 Self-induced motion and asymptotic expansion of the velocity field in the vicinity of a helical vortex filament. Phys. Fluids 10, 607614.CrossRefGoogle Scholar
Leishman, J. G. 2000 Principles of Helicopter Aerodynamics. Cambridge University Press.Google Scholar
McTavish, S., Feszty, D. & Nitzsche, F. 2013 An experimental and computational assessment of blockage effects on wind turbine wake development. Wind Energy doi:10.1002/we.1648.Google Scholar
Medici, D., Ivanell, S., Dahlberg, J.-Å. & Alfredsson, P. H. 2011 The upstream flow of a wind turbine: blockage effect. Wind Energy 14, 691697.Google Scholar
Mikkelsen, R. & Sørensen, J. N. 2002 Modeling of wind tunnel blockage. Proceedings of the 2002 Global Windpower Conference and Exhibit. European Wind Energy Association.Google Scholar
Okulov, V. L. & Sørensen, J. N. 2010 Maximum efficiency of wind turbine rotors using Joukowsky and Betz approaches. J. Fluid Mech. 649, 497508.Google Scholar
Ricca, R. L. 1994 The effect of torsion on the motion of a helical vortex filament. J. Fluid Mech. 273, 241259.Google Scholar
Segalini, A. & Alfredsson, P. H. 2013 A simplified vortex model of propeller and wind-turbine wakes. J. Fluid Mech. 725, 91116.CrossRefGoogle Scholar
Sørensen, J. N. & Shen, W. Z. 2002 Numerical modelling of wind turbine wakes. Trans. ASME: J. Fluids Engng 124, 393399.Google Scholar
Troldborg, N.2008 Actuator line modeling of wind turbine wakes. PhD thesis, Technical University of Denmark.Google Scholar
Vermeer, L. J., Sørensen, J. N. & Crespo, A. 2003 Wind turbine wake aerodynamics. Prog. Aerosp. Sci. 39, 467510.Google Scholar
Werle, M. J. 2010 Wind turbine wall-blockage performance corrections. J. Propul. Power 26, 13171321.Google Scholar
Wilson, R. E. 1994 Aerodynamic behavior of wind turbines. In Wind Turbine Technology, Fundamental Concepts of Wind Turbine Engineering (ed. Spera, D.), pp. 215282. ASME Press.Google Scholar