Effect of a Wind Lens diffuser on turbulent flow





Wind Lens, diffuser, turbulent flow, turbulence intensity


This article is aimed to measure the effect of a wind lens diffuser on turbulent flow. The study was conducted in the boundary layer wind tunnel of the Research Institute for Applied Mechanics at Kyushu University, Japan, between March and May 2019. A hot wire anemometer with a moving mechanism was used to conduct three tests. First, a characterization of the flow inside the wind tunnel was measured without the grid. Second, the turbulence intensity in the wind tunnel axis was measured this time with the grid in place. Third, the wind lens effect on the incident wind speed was determined at different levels of turbulence intensity. The wind speed in the tunnel without the turbulence grid was almost constant, approximately 9.6 m/s. When the grid was placed, a decreasing turbulence intensity was recorded in the axis of the wind tunnel, from 28.6 % at 500 mm from the grid to 5 % turbulence intensity at 3100 mm from the grid. When the effect of the wind lens was measured on the turbulent flow, wind speed increased up to 20 %. The wind lens proved suitable for wind turbines operating in turbulent flow, by increasing wind speed in all tests and generating a greater increase in the conditions with greater turbulence intensity.


Aouini, A. (2012). System for Converting Wind Energy. WO2012039688 -WIPO IP PORTAL. [Patent]. https://bit.ly/3303haj

Burton, T., Jenkins, N., Sharpe, D., & Bossanyi, E. (2011). Wind Energy Handbook. https://dx.doi.org/10.1002/9781119992714

Clements, L., & Chowdhury, A. (2019). Performance evaluation of wind lens in turbulent environment. Energy Procedia, 160, 777–782. https://dx.doi.org/10.1016/j.egypro.2019.02.161

El-Shahat, A., Hasan, M.-M., & Wu, Y., (2018). Vortex Bladeless Wind Generator for Nano-Grids. 2018 IEEE Global Humanitarian Technology Conference (GHTC). https://dx.doi.org/10.1109/GHTC.2018.8601572

Göltenbott, U., Ohya, Y., Yoshida, S., & Jamieson, P. (2017). Aerodynamic interaction of diffuser augmented wind turbines in multi-rotor systems. Renewable Energy, 112, 25–34. https://dx.doi.org/10.1016/j.renene.2017.05.014

Hashem, I., Mohamed, M. H., & Hafiz, A. A. (2017). Aero-acoustics noise assessment for Wind-Lens turbine. Energy, 118, 345–368. https://dx.doi.org/10.1016/j.energy.2016.12.049

Heikal, H.A. et al., (2018). On the actual power coefficient by theoretical developing of the diffuser flange of wind-lens turbine. Renewable Energy, 125, 295–305. https://dx.doi.org/10.1016/j.renene.2018.02.100

Hu, J.-F., & Wang, W.-X. (2015). Upgrading a Shrouded Wind Turbine with a Self-Adaptive Flanged Diffuser. Energies, 8(6), 5319–5337. https://dx.doi.org/10.3390/en8065319

Jang, H., Kim, D., Hwang, Y., Paek, I., Kim, S., & Baek, J. (2019). Analysis of Archimedes Spiral Wind Turbine Performance by Simulation and Field Test. Energies, 12(24), 4624. https://dx.doi.org/10.3390/en12244624

Kanomax. (s. f.). Hot-Wire Anemometer Smart CTA. Model 7250. https://www.kanomax.co.jp/img_data/file_731_1550041294.pdf

Keramat Siavash, N., Najafi, G., Tavakkoli Hashjin, T., Ghobadian, B., & Mahmoodi, E. (2020). Mathematical modeling of a horizontal axis shrouded wind turbine. Renewable Energy, 146, 856–866. https://dx.doi.org/10.1016/j.renene.2019.07.022

Khamlaj, T. A., & Rumpfkeil, M. P. (2018). Analysis and optimization of ducted wind turbines. Energy, 162, 1234–1252. https://dx.doi.org/10.1016/j.energy.2018.08.106

Kosasih, B., & Saleh Hudin, H. (2016). Influence of inflow turbulence intensity on the performance of bare and diffuser-augmented micro wind turbine model. Renewable Energy, 87, 154–167. https://dx.doi.org/10.1016/j.renene.2015.10.013

Maftouni, N., & Parsa, H. (2019). Effects of Implementing a Diffuser around the Wind Turbine. 2019 International Conference on Power Generation Systems and Renewable Energy Technologies (PGSRET). https://dx.doi.org/10.1109/PGSRET.2019.8882727

Nasution, A., & Purwanto, D. W. (2011). Optimized curvature interior profile for Diffuser Augmented Wind Turbine (DAWT) to increase its energy-conversion performance. 2011 IEEE Conference on Clean Energy and Technology (CET). http://dx.doi.org/10.1109/CET.2011.6041483

Ohya, Y. (2019). Multi-Rotor Systems Using Five Ducted Wind Turbines for Power Output Increase (Multi Lens Turbine). AIAA Scitech Forum. http://dx.doi.org/10.2514/6.2019-1296

Ohya, Y., & Karasudani, T. (2010). A Shrouded Wind Turbine Generating High Output Power with Wind-lens Technology. Energies, 3(4), 634–649. https://doi.org/10.3390/en3040634

Ohya, Y., Karasudani, T., Nagai, T., & Watanabe, K. (2017). Wind lens technology and its application to wind and water turbine and beyond. Renewable Energy and Environmental Sustainability, 2, 2. http://dx.doi.org/10.1051/rees/2016022

Ohya, Y., Miyazaki, J., Göltenbott, U., & Watanabe, K. (2017). Power Augmentation of Shrouded Wind Turbines in a Multirotor System. Journal of Energy Resources Technology, 139(5). http://dx.doi.org/10.1115/1.4035754

Richmond-Navarro, G., Calderon-Munoz, W. R., LeBoeuf, R., & Castillo, P. (2017). A Magnus Wind Turbine Power Model Based on Direct Solutions Using the Blade Element Momentum Theory and Symbolic Regression. IEEE Transactions on Sustainable Energy, 8(1), 425–430. https://dx.doi.org/10.1109/TSTE.2016.2604082

Riyanto, Pambudi, N. A., Febriyanto, R., Wibowo, K. M., Setyawan, N. D., Wardani, N. S., … Rudiyanto, B. (2019). The Performance of Shrouded Wind Turbine at Low Wind Speed Condition. Energy Procedia, 158, 260–265. http://dx.doi.org/10.1016/j.egypro.2019.01.086

SAGE Journals. (2006). Book Review: Wind Energy in the Built Environment — Concentrator Effects of Buildings. Wind Engineering, 30(5), 451–452. http://dx.doi.org/10.1260/030952406779502623

Takahashi, S., Hata, Y., Ohya, Y., Karasudani, T., & Uchida, T. (2012). Behavior of the Blade Tip Vortices of a Wind Turbine Equipped with a Brimmed-Diffuser Shroud. Energies, 5(12), 5229–5242. http://dx.doi.org/10.3390/en5125229

Wang, W.-X., Matsubara, T., Hu, J., Odahara, S., Nagai, T., Karasutani, T., & Ohya, Y. (2015). Experimental investigation into the influence of the flanged diffuser on the dynamic behavior of CFRP blade of a shrouded wind turbine. Renewable Energy, 78, 386–397. http://dx.doi.org/10.1016/j.renene.2015.01.028

Watanabe, K., Fukutomi, S., Ohya, Y., & Uchida, T. (2020). An Ignored Wind Generates More Electricity: A Solar Updraft Tower to a Wind Solar Tower. International Journal of Photoenergy, 2020, 1–9. https://dx.doi.org/10.1155/2020/4065359

Yuji, O., & Koichi, W. (2019). A New Approach Toward Power Output Enhancement Using Multirotor Systems With Shrouded Wind Turbines. Journal of Energy Resources Technology, 141(5). http://dx.doi.org/10.1115/1.4042235

Zhu, H., Sueyoshi, M., Hu, C., & Yoshida, S. (2019). A study on a floating type shrouded wind turbine: Design, modeling and analysis. Renewable Energy, 134, 1099–1113. https://doi.org/10.1016/j.renene.2018.09.028



How to Cite

Effect of a Wind Lens diffuser on turbulent flow. (2021). Uniciencia, 35(2), 1-15. https://doi.org/10.15359/ru.35-2.7



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How to Cite

Effect of a Wind Lens diffuser on turbulent flow. (2021). Uniciencia, 35(2), 1-15. https://doi.org/10.15359/ru.35-2.7

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