Abstract
This study presents an innovative wind tunnel approach to evaluate the efficiency of Vertical-Axis Wind Turbines (VAWT) in turbulent flows, to study their integration in urban environments. The first part of the research is devoted to obtaining highly-turbulent wind profiles in the wind tunnel, with the use of different configurations of square grids. A careful study and validation of this technique is done, in order to obtain uniform wind conditions with the adequate values of turbulence intensity and length scales to model the urban flows. The set-up is used to test a H-Darrieus VAWT under values of turbulence over 5%, in comparison with the operation of the turbine under free stream. The preliminary results show that high levels of turbulence do have a significant effect in turbine performance, with increases reaching 15%. The errors in the measurements are analysed to identify the ways to improve the set-up and possible future developments.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Abbreviations
- A :
-
Frontal Area (m2)
- b :
-
Bar width (m)
- c :
-
Turbine blade chord (m)
- C P :
-
Power Coefficient (–)
- C Pfs :
-
Maximum Power Coefficient at free stream conditions (–)
- D :
-
Diameter of the rotor (m)
- f :
-
Frequency (Hz)
- H :
-
Height of the rotor (m)
- I u :
-
Intensity of Turbulence in wind direction (–)
- L ux :
-
Integral Length Scale of turbulence in wind direction (m)
- M :
-
Mesh size (m)
- Q :
-
Torque (Nm)
- R :
-
Turbine Radius (m)
- U :
-
Longitudinal wind speed (m/s)
- u :
-
Variable component of wind speed in wind direction (m/s)
- V :
-
Total wind speed (m/s)
- v, w :
-
Wind speed components transversal to wind direction (m/s)
- x :
-
Distance from grid (m)
- λ :
-
Tip Speed Ratio (–)
- λ fs :
-
Optimal Tip Speed Ratio for the free stream case (–)
- ρ :
-
Density of air (kg/m3)
- σ x :
-
Standard deviation of variable x
- ω :
-
Angular speed (s−1)
- HAWT:
-
Horizontal-Axis Wind Turbines
- VAWT:
-
Vertical-Axis Wind Turbines
References
Barlow, J.F., Drew, D.R.: Wind flow in the urban environment. In: WINERCOST Workshop ‘Trends and Challenges for Wind Energy Harvesting’ ‘Trends and Challenges for Wind Energy Harvesting’, Coimbra, Portugal (2015)
Janajreha, I., Su, L., Alan, F.: Wind energy assessment: Masdar City case study. Renew. Energy 52, 8–15 (2013)
Paraschivoiu, I.: Wind Turbine Design: With Emphasis on Darrieus Concept. Presses inter Polytechnique (2002)
Olivari, D., Benocci, C.: An Introduction to the Mechanics of Turbulence. Course note 157, Von Karman Institute for Fluid Dynamics (2013)
Möllerström, E., Ottermo, F., Goude, A., Eriksson, S., Hylander, J., Bernhoff, H.: Turbulence influence on wind energy extraction for a medium size vertical axis wind turbine. Wind Energy 19, 1963–1973 (2016)
Lubitz, W.D.: Impact of ambient turbulence on performance of a small wind turbine. Renew. Energy 61, 69–73 (2014)
Pagnini, L.C., Burlando, M., Repetto, M.P.: Experimental power curve of small-size wind turbines in turbulent urban environment. Appl. Energy 154, 112–121 (2015)
Bertényi, T., Wickins, C., McIntosh, S.: Enhanced energy capture through gust-tracking in the urban wind environment. In: 48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition, 4–7 January 2010, Orlando, Florida (2010)
Mannini, C., Marra, A.M., Pigolotti, L., Bartoli, G.: Unsteady pressure and wake characteristics of a benchmark rectangular section in smooth and turbulent flow. In: 14th International Conference on Wind Engineering, Porto Alegre, Brazil (2015)
Burton, T.: Wind Energy Handbook. Wiley (2001)
Roach, P.E.: The generation of nearly isotropic turbulence by means of grids. Int. J. Heat Fluid Flow 8(2), 82–92 (1987)
Laneville, A.: Effects of turbulence on wind induced vibrations of bluff cylinders (Ph.D. thesis). University of British Columbia, Vancouver, Canada (1973)
Dallman, A.R.: Flow and turbulence in urban areas (PhD thesis). University of Notre Dame, Indiana, USA (2013)
Van Dyke, M.: An Album of Fluid Motion, 14th ed. Parabolic Press, Inc. (1982)
Bearman, P.W., Morel, T.: Effect of free stream turbulence on the flow around bluff bodies. Prog. Aerosp. Sci. 20(2), 97–123 (1983)
Baines, W.D., Peterson, E.G.: An investigation of flow through screens. Trans. ASME 72 (1951)
De Troyer, T., Runacres, M.: Wind Tunnel Testing of a Pair of VAWTs for Offshore Applications (2016)
Jeong1, H., Lee, S., Kwon, S.D.: Wind tunnel interference effects on power performance of small Darrieus wind turbines. In: The 2014 World Congress on Advances in Civil, Environmental, and Materials Research (ACEM14), Busan, Korea (2014)
Pope, A., Harper, J.J.: Low Speed Wind Tunnel Testing. Wiley, New York (1966)
Dénos, R.: Fundamentals of Data Acquisition and Processing. Course Note 171, von Karman Institute for Fluid Dynamics (2005)
ITTC—Recommended Procedures and Guidelines, Uncertainty Analysis: Particle Imaging Velocimetry. In: 25th International Towing Tank Conference (2008)
Acknowledgements
The present research takes part in the European Innovative Training Network (ITN) AEOLUS4FUTURE “Efficient Harvesting of the Wind Energy”. The project is funded by the Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement No. 643167.
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2018 Springer International Publishing AG
About this paper
Cite this paper
Carbó Molina, A., Bartoli, G., De Troyer, T. (2018). Generation of Uniform Turbulence Profiles in the Wind Tunnel for Urban VAWT Testing. In: Battisti, L., Ricci, M. (eds) Wind Energy Exploitation in Urban Environment. TUrbWind 2017. Green Energy and Technology. Springer, Cham. https://doi.org/10.1007/978-3-319-74944-0_3
Download citation
DOI: https://doi.org/10.1007/978-3-319-74944-0_3
Published:
Publisher Name: Springer, Cham
Print ISBN: 978-3-319-74943-3
Online ISBN: 978-3-319-74944-0
eBook Packages: EnergyEnergy (R0)