Effect of Blade Number on a Straight-Bladed Vertical-Axis Darreius Wind Turbine
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 32870
Effect of Blade Number on a Straight-Bladed Vertical-Axis Darreius Wind Turbine

Authors: Marco Raciti Castelli, Stefano De Betta, Ernesto Benini


This paper presents a mean for reducing the torque variation during the revolution of a vertical-axis wind turbine (VAWT) by increasing the blade number. For this purpose, twodimensional CDF analysis have been performed on a straight-bladed Darreius-type rotor. After describing the computational model, a complete campaign of simulations based on full RANS unsteady calculations is proposed for a three, four and five-bladed rotor architecture characterized by a NACA 0025 airfoil. For each proposed rotor configuration, flow field characteristics are investigated at several values of tip speed ratio, allowing a quantification of the influence of blade number on flow geometric features and dynamic quantities, such as rotor torque and power. Finally, torque and power curves are compared for the analyzed architectures, achieving a quantification of the effect of blade number on overall rotor performance.

Keywords: CFD, VAWT, NACA 0021, blade number

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1079974

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 5290


[1] European Wind Energy Association, EU energy policy after 2020,www.ewea.org, 2011.
[2] M. Raciti Castelli, E. Benini, Effect of blade inclination angle on a Darreius wind turbine, Journal of turbomachinery,2012.
[3] S. Li, Y. Li, Numerical study on the performance effects of solidity on the straight-bladed vertical axes wind turbine, Power and energy Engineering Conference, 2010.
[4] I.Paraschivoiu, "Wind turbine design with emphasis on Darrieus concept", Polytechnic International Press, Canada,2002.
[5] M. Dunquette, K. Visser, Numerical implications of solidity and Blade Number on Rotor Performance of horizontal-axis wind turbines, Journal of Solar Energy Engineering, November 2003.
[6] S. Ferreira, H. Bijl, G. van Bussel ,G. van Kuik, Simulating dynamic stall in a 2D VAWT: modeling strategy, verification and validation with particle image velocimetry data, The Science of making torque from wind. Journal of Physics: Conference Series 75,2007.
[7] S. Wang, Z. Tao, Numerical investigation on dynamic stall associated with low reynolds number flows over airfoils, 2nd International Conference on Computer Engineering and Technology,2010.
[8] R. Howell, N. Qin, J. Edwards, N. Durrani. Wind tunnel and numerical study of a small vertical axis wind turbine, Renewable Energy 35, 2010.
[9] J. H. Strickland: The Darrieus turbine: a performance prediction model using multiple streamtube, SAND 75e0431,1975.
[10] Fluent Inc., Fluent User-s Manual,pp. 193-194, 2006.
[11] R.M. Cummings, J.R. Forsythe, S.A. Morton, K.D. Squires, Computational challenges in high angle of attack flow prediction, Prog Aerospace Sci, 2003.
[12] M. Raciti Castelli, G. Pavesi, L. Battisti, E. Benini, G. Ardizzon, Modeling strategy and numerical validation for a Darrieus vertical axis micro-wind turbine, ASME 2010 International Mechanical Engineering Congress & Exposition, Vancouver, British Columbia, Canada, November 12e18 2010.
[13] M. McMullen, A. Jameson, J.J. Alonso, Acceleration of convergence to a periodic steady state in turbomachinery flows, 39th AIAA aerospace sciences meeting & exhibit. Reno, NV: AIAA; January 8-11 2001.
[14] M. Raciti Castelli, A. Englaro, E. Benini, The Dareius wind turbine:Proposal for new performance prediction model based on CFD, Energy, Volume 36, Issue 8, August 2011.
[15] G.H. Yu, X.C. Zhu, Z.H. Du, Numerical simulation of a wind turbine airfoil: dynamic stall and comparison with experiments, Power and Energy Journal Vol. 224, 2010.