Figures & data
Figure 1. Characteristic of wind turbines (Ahmed and Gawad Citation2016).
![Figure 1. Characteristic of wind turbines (Ahmed and Gawad Citation2016).](/cms/asset/45f361b8-8f35-4262-ba3c-092e0f16e1ac/ljge_a_2005605_f0001_b.gif)
Figure 2. Darrieus types VAWT design concepts (Dabachi, Rahmouni, and Bouksour Citation2020).
![Figure 2. Darrieus types VAWT design concepts (Dabachi, Rahmouni, and Bouksour Citation2020).](/cms/asset/fa15bf35-c7a1-4fa6-b652-2ea67797dbcf/ljge_a_2005605_f0002_oc.jpg)
Figure 3. Lift-type VAWTs trends (Möllerström et al. Citation2019).
![Figure 3. Lift-type VAWTs trends (Möllerström et al. Citation2019).](/cms/asset/647b6f73-6737-4429-91e5-fd973a0f3f0b/ljge_a_2005605_f0003_oc.jpg)
Figure 4. Fixed and variable pitch VAWTs configuration (Sagharichi, Zamani, and Ghasemi Citation2018).
![Figure 4. Fixed and variable pitch VAWTs configuration (Sagharichi, Zamani, and Ghasemi Citation2018).](/cms/asset/189d35ab-1c33-4303-ac53-dfd38f0adf46/ljge_a_2005605_f0004_oc.jpg)
Table 1. Comparison of four different pitching strategies for H-Darrieus VAWT (Zhao et al. Citation2017).
Figure 5. Aerodynamic simulations for the test H-Darrieus rotor operating at λ of 4.5 (Soraghan et al. Citation2013), a) AoA b) Induction Factor c) Tangential Force Coefficient d) Normal Force Coefficient.
![Figure 5. Aerodynamic simulations for the test H-Darrieus rotor operating at λ of 4.5 (Soraghan et al. Citation2013), a) AoA b) Induction Factor c) Tangential Force Coefficient d) Normal Force Coefficient.](/cms/asset/25a05b8f-a137-429a-bb55-efa62def753a/ljge_a_2005605_f0005_oc.jpg)
Figure 6. Variation AoA vs azimuthal angle for a λ of 1.5. a) high solidity on the variable pitch (Sagharichi, Zamani, and Ghasemi Citation2018) b) the variation of pitch angle at different azimuth positions vs AoA (Elkhoury, Kiwata, and Aoun Citation2015).
![Figure 6. Variation AoA vs azimuthal angle for a λ of 1.5. a) high solidity on the variable pitch (Sagharichi, Zamani, and Ghasemi Citation2018) b) the variation of pitch angle at different azimuth positions vs AoA (Elkhoury, Kiwata, and Aoun Citation2015).](/cms/asset/480ceaf0-e0cf-40c6-8f82-795cfa6156e4/ljge_a_2005605_f0006_oc.jpg)
Figure 7. Instantaneous pressure coefficient through mid-plane of an FP and VP angles VAWT at λ = 1 (Elkhoury, Kiwata, and Aoun Citation2015).
![Figure 7. Instantaneous pressure coefficient through mid-plane of an FP and VP angles VAWT at λ = 1 (Elkhoury, Kiwata, and Aoun Citation2015).](/cms/asset/bb2c2692-e0cf-49ee-9e54-208c75bccf13/ljge_a_2005605_f0007_oc.jpg)
Figure 9. Vortex structure for lower and higher tip speed ratios at different azimuthal positions (θ) (Mukherjee, Jain, and Saha Citation2016).
![Figure 9. Vortex structure for lower and higher tip speed ratios at different azimuthal positions (θ) (Mukherjee, Jain, and Saha Citation2016).](/cms/asset/5ad81254-e886-44a0-8444-d0ee02992e97/ljge_a_2005605_f0009_oc.jpg)
Figure 10. Instantaneous moment coefficient for the last turbine revolution for different tip speed ratios using various azimuthal increments (σ = 0.12) (Rezaeiha, Montazeri, and Blocken Citation2018b).
![Figure 10. Instantaneous moment coefficient for the last turbine revolution for different tip speed ratios using various azimuthal increments (σ = 0.12) (Rezaeiha, Montazeri, and Blocken Citation2018b).](/cms/asset/2138931a-3e90-4cd5-bfe1-451d6fcaec19/ljge_a_2005605_f0010_oc.jpg)
Figure 11. Airfoil performance evaluations, a) instantaneous rotor torque coefficient as a function of the blade at the midsection azimuth coordinate of NACA0012airfoil blade(Castelli et al. Citation2013) b) instantaneous best airfoils torque coefficients different family of an airfoil at 4 tip speed ratio (Mohamed, Ali, and Hafiz Citation2015; Mohamed, Dessoky, and Alqurashi Citation2019).
![Figure 11. Airfoil performance evaluations, a) instantaneous rotor torque coefficient as a function of the blade at the midsection azimuth coordinate of NACA0012airfoil blade(Castelli et al. Citation2013) b) instantaneous best airfoils torque coefficients different family of an airfoil at 4 tip speed ratio (Mohamed, Ali, and Hafiz Citation2015; Mohamed, Dessoky, and Alqurashi Citation2019).](/cms/asset/baff3461-9865-44aa-b73a-446029c9c4b2/ljge_a_2005605_f0011_oc.jpg)
Figure 12. Comparative performance of NACA0015 to four S-series airfoils at different azimuth angles (Cao et al. Citation2018).
![Figure 12. Comparative performance of NACA0015 to four S-series airfoils at different azimuth angles (Cao et al. Citation2018).](/cms/asset/01064c7c-5b3b-4d1f-9699-87f48d174200/ljge_a_2005605_f0012_oc.jpg)
Figure 13. The effect of solidity on Darrieus peak efficiency (Kirke and Lazauskas Citation2011).
![Figure 13. The effect of solidity on Darrieus peak efficiency (Kirke and Lazauskas Citation2011).](/cms/asset/1b5ddad9-d6f5-4e83-9be4-6f48481733bd/ljge_a_2005605_f0013_oc.jpg)
Figure 14. Four bar linkage mechanism in H-Darrieus wind turbine a) 2D view (Kiwata et al. Citation2010), and the 3D view (right) (Sagharichi, Maghrebi, and ArabGolarcheh Citation2016; Sagharichi, Zamani, and Ghasemi Citation2018).
![Figure 14. Four bar linkage mechanism in H-Darrieus wind turbine a) 2D view (Kiwata et al. Citation2010), and the 3D view (right) (Sagharichi, Maghrebi, and ArabGolarcheh Citation2016; Sagharichi, Zamani, and Ghasemi Citation2018).](/cms/asset/e5d6c651-8313-4fb0-a13c-c6d68c504072/ljge_a_2005605_f0014_b.gif)
Figure 15. Schematics of the over-speed prevention device using double tail vanes for variable pitch VAWT (Yamada et al. Citation2012).
![Figure 15. Schematics of the over-speed prevention device using double tail vanes for variable pitch VAWT (Yamada et al. Citation2012).](/cms/asset/c59d87bf-0eac-47fd-a641-6e1da2f6399d/ljge_a_2005605_f0015_oc.jpg)
Figure 16. Sensor and actuating systems layout for individual pitch control system (Hwang et al. Citation2006).
![Figure 16. Sensor and actuating systems layout for individual pitch control system (Hwang et al. Citation2006).](/cms/asset/e8fd4afc-c25d-4809-8257-ba69431ef24b/ljge_a_2005605_f0016_oc.jpg)
Figure 17. MLP-ANN variable pitch control system (Abdalrahman, Melek, and Lien Citation2017).
![Figure 17. MLP-ANN variable pitch control system (Abdalrahman, Melek, and Lien Citation2017).](/cms/asset/7c0ed9b8-95fd-4623-a05b-0770fae0185a/ljge_a_2005605_f0017_oc.jpg)
Figure 18. Staggered arrangement of H-Darrieus turbine in a wind farm a) flow domain b) all turbines rotating in the same direction c) One turbine counters rotating.
![Figure 18. Staggered arrangement of H-Darrieus turbine in a wind farm a) flow domain b) all turbines rotating in the same direction c) One turbine counters rotating.](/cms/asset/3b0a9c80-04d7-4627-aaba-07b6ec9403cf/ljge_a_2005605_f0018_oc.jpg)
Figure 19. Key elements to be considered during wind turbine blade materials selection (Zangenberg, Brøndsted, and Koefoed Citation2014).
![Figure 19. Key elements to be considered during wind turbine blade materials selection (Zangenberg, Brøndsted, and Koefoed Citation2014).](/cms/asset/d498468d-07c2-49d1-bc15-0a06ed8806bf/ljge_a_2005605_f0019_b.gif)
Figure 20. Comparison of the position of natural fibers against synthetic fibers concerning specific tensile strength and stiffness (Ashby Citation2008).
![Figure 20. Comparison of the position of natural fibers against synthetic fibers concerning specific tensile strength and stiffness (Ashby Citation2008).](/cms/asset/8d408bf2-ec89-4d5d-aa41-571a3681bdf5/ljge_a_2005605_f0020_oc.jpg)
Figure 21. H-Darrieus-Savonieus Hybrid WT performance (Mohamed Citation2013). a) Static torque coefficient and hybrid system. b) Torque coefficients for an individual and hybrid turbine.
![Figure 21. H-Darrieus-Savonieus Hybrid WT performance (Mohamed Citation2013). a) Static torque coefficient and hybrid system. b) Torque coefficients for an individual and hybrid turbine.](/cms/asset/ffd242cf-c04d-4b0e-90a1-793f172368b2/ljge_a_2005605_f0021_oc.jpg)
Figure 22. Cascade model of Darrieus VAWT (Kumar et al. Citation2017a).
![Figure 22. Cascade model of Darrieus VAWT (Kumar et al. Citation2017a).](/cms/asset/2f694401-9e0d-4e79-8d9c-f30d2ea1e3c1/ljge_a_2005605_f0022_oc.jpg)
Figure 23. Schematics of vortices model. a) Vortex model filaments in straight-blade (Griffith et al. Citation2018). b) Strength of different vortices of FP and VP H-Darrieus VAWT (Zhao et al. Citation2019).
![Figure 23. Schematics of vortices model. a) Vortex model filaments in straight-blade (Griffith et al. Citation2018). b) Strength of different vortices of FP and VP H-Darrieus VAWT (Zhao et al. Citation2019).](/cms/asset/18be3b06-de4c-444e-bb49-bdf1742cd2a0/ljge_a_2005605_f0023_oc.jpg)
Figure 24. Single-stream tube model (Kumar et al. Citation2017a).
![Figure 24. Single-stream tube model (Kumar et al. Citation2017a).](/cms/asset/b2c54283-efc3-4174-b303-8ea7cbf492b5/ljge_a_2005605_f0024_oc.jpg)
Figure 25. Multiple stream tube model (Kumar et al. Citation2017a).
![Figure 25. Multiple stream tube model (Kumar et al. Citation2017a).](/cms/asset/541ad55d-909f-4210-b736-4d252114faa0/ljge_a_2005605_f0025_oc.jpg)
Figure 26. Double multiple stream tube models (Kumar et al. Citation2017a).
![Figure 26. Double multiple stream tube models (Kumar et al. Citation2017a).](/cms/asset/51117faf-591b-489e-a68d-c9097d8089f2/ljge_a_2005605_f0026_oc.jpg)
Figure 27. H-Darrieus blade vortex. a) flow streamlines in the tip region, skin friction lines, and z velocity component on the blade suction surface (Balduzzi et al. Citation2017). b) instantaneous torque at different blade sections (Jiang et al. Citation2020).
![Figure 27. H-Darrieus blade vortex. a) flow streamlines in the tip region, skin friction lines, and z velocity component on the blade suction surface (Balduzzi et al. Citation2017). b) instantaneous torque at different blade sections (Jiang et al. Citation2020).](/cms/asset/dd3d8993-2de9-4868-acdf-9244f018907f/ljge_a_2005605_f0027_oc.jpg)
Table 2. Strength and weakness of different analytical models (Batista et al.; Hirsch and Mandal Citation1987; Islam, Ting, and Fartaj Citation2008).
Table 3. Accuracy comparison of aerodynamic models (Ferreira et al. Citation2014).
Figure 28. The flow domain ratio effects on the turbine torque coefficient (Ferreira et al. Citation2014).
![Figure 28. The flow domain ratio effects on the turbine torque coefficient (Ferreira et al. Citation2014).](/cms/asset/7bddf3be-35e9-473f-8e90-63d09e7da6d7/ljge_a_2005605_f0028_b.gif)
Figure 29. CFD model comparison of power coefficient CP as a function of TSR and experimental studies results used for H-Darrieus VAWT.
![Figure 29. CFD model comparison of power coefficient CP as a function of TSR and experimental studies results used for H-Darrieus VAWT.](/cms/asset/ad14566d-9f38-4f58-861c-2e611d62046a/ljge_a_2005605_f0029_oc.jpg)
Figure 30. Structural analysis platform of vertical axis wind turbines (VAWTs) (Lin, Xu, and Xia Citation2019).
![Figure 30. Structural analysis platform of vertical axis wind turbines (VAWTs) (Lin, Xu, and Xia Citation2019).](/cms/asset/c2990e4e-d52e-4844-87c1-63e82ca99e86/ljge_a_2005605_f0030_oc.jpg)
Figure 31. Modal analysis of straight-bladed H-Darrieus WT. a) blade deflection b) natural frequency.
![Figure 31. Modal analysis of straight-bladed H-Darrieus WT. a) blade deflection b) natural frequency.](/cms/asset/8ab1a411-4ab7-47fd-8998-e808c5c020e9/ljge_a_2005605_f0031_oc.jpg)
Figure 32. Multi-body dynamics of typical VAWT (Verkinderen and Imam Citation2015). a) FE model of 15 m mast and first three mode shapes. b) Mast, turbine and coupled system natural frequencies for different mast lengths.
![Figure 32. Multi-body dynamics of typical VAWT (Verkinderen and Imam Citation2015). a) FE model of 15 m mast and first three mode shapes. b) Mast, turbine and coupled system natural frequencies for different mast lengths.](/cms/asset/67a62aa4-9711-4692-84b2-bb92b8b2bfd8/ljge_a_2005605_f0032_oc.jpg)
Figure 33. The architecture of ANN (Teksin, Azginoglu, and Akansu Citation2022).
![Figure 33. The architecture of ANN (Teksin, Azginoglu, and Akansu Citation2022).](/cms/asset/5eaeaef0-0710-4a33-b8fc-f5656f3b9baf/ljge_a_2005605_f0033_b.gif)
Figure 35. Typical System coupling. a) one-way coupling (Wang et al. Citation2015) (the left side one) b) Two-way coupling (Rafiee, Tahani, and Moradi Citation2016), (the right side one).
![Figure 35. Typical System coupling. a) one-way coupling (Wang et al. Citation2015) (the left side one) b) Two-way coupling (Rafiee, Tahani, and Moradi Citation2016), (the right side one).](/cms/asset/c746f8d0-76d7-4def-aa1d-f2a52f54b6e4/ljge_a_2005605_f0035_oc.jpg)
Table 4. Simulation Parameter.
Table 5. Parametric studies of H-Darrieus wind turbine Summary