AIMS Energy, 2019, 7(6): 841-856. doi: 10.3934/energy.2019.6.841

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Parametric study of a diffuser for horizontal axis wind turbine power augmentation

School of Mechanical and Industrial Engineering, Addis Ababa Institute of Technology, Addis Ababa University, Addis Ababa, Ethiopia

For a wider dissemination and implementation of small wind turbines for rural electrification in developing countries, the cost of the system must be reduced. When searching for systems that are efficient and economical, Diffuser Augmented Wind turbine seems to have a potential role by increasing the power output and reducing the cost of the system most importantly at low speeds. In this paper, a detailed study has been done on Diffuser Augmented Wind Turbines to find a parametric relationship for power augmentation for horizontal axis wind turbines. A suitable diffuser was selected and its parameters were identified and their relationships were formulated based on Computational Fluid Dynamics. The result has been validated using experimental analysis. Based on the result, the power output and performance of a wind turbine is improved while using diffuser. The result shows the velocity peaks at a location immediately after the diffuser inlet. The velocity, then, levels off and further decreases as the flow continues to the diffuser outlet and exits it. This suggests a possible location of a wind turbine at the vicinity of the inlet. Based on the result, the length of the diffuser and the flange height were the major parameters to be considered. Maximum velocity ratios up to 1.5 were obtained with potential power increase of more than 2 times. It has also been observed that velocity ratios of up to 1.3 can be achieved with more compact diffusers potentially reducing the cost of the diffuser and the whole system. The mathematical relations obtained for the major parameters and the velocity ratio can be used in the performance prediction and optimization of a diffuser. Finally, possible directions for further research are recommended considering that this work shows a good agreement with previous works and predictions.
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References

1. Lighting Africa.org (2012) In collaboration with: energy sector overview 1-9. Available from: https://www.lightingafrica.org/wp-content/uploads/2016/07/26_Ethiopia-FINAL-August-2012_LM.pdf.

2. Ma JT, Xu LS ZK et al. (2012) Master plan report of wind and solar energy in the federal democratic republic of Ethiopia. HydroChina Corp 236.

3. Ministry of Foreign Affairs of Denmark (2016) Accelerating wind power generation in Ethiopia thematic programme document. 1-49.

4. Barnes DF, Golumbeanu R, Diaw I (2016) Beyond electricity access: output-based aid and rural electrification in Ethiopia. 1: 1-148.

5. Ani SO, Polinder H, Ferreira JA (2011) Energy yield of two generator systems for small wind turbine application. 2011 IEEE Int Electr Mach Drives Conf 735-740.

6. Dilimulati A, Stathopoulos T, Paraschivoiu M (2018) Wind turbine designs for urban applications: a case study of shrouded diffuser casing for turbines. J Wind Eng Ind Aerodyn 175: 179-192.    

7. Ledo L, Kosasih PB, Cooper P (2011) Roof mounting site analysis for micro-wind turbines. Renew Energy 36: 1379-1391.    

8. Rafailidis S (1997) Influence of building areal density and roof shape on the wind characteristics above a town. Boundary-Layer Meteorol 85: 255-271.    

9. Sorribes-Palmer F, Sanz-Andres A, Ayuso L, et al. (2017) Mixed CFD-1D wind turbine diffuser design optimization. Renew Energy 105: 386-399.    

10. Jafari SAH, Kosasih B (2014) Flow analysis of shrouded small wind turbine with a simple frustum diffuser with computational fluid dynamics simulations. J Wind Eng Ind Aerodyn 125: 102-110.    

11. Bontempo R, Manna M (2014) Performance analysis of open and ducted wind turbines. Appl Energy 136: 405-416.    

12. Shonhiwa C, Makaka G (2016) Concentrator augmented wind turbines: a review. Renew Sustain Energy Rev 59: 1415-1418.    

13. Khamlaj TA, Rumpfkeil MP (2018) Analysis and optimization of ducted wind turbines. Energy 162: 1234-1252.    

14. Wong KH, Chong WT, Yap HT, et al. (2014) The design and flow simulation of a power-augmented shroud for urban wind turbine system. Energy Procedia 61: 1275-1278.    

15. Nobile R, Vahdati M, Barlow JF, et al. (2014) Unsteady flow simulation of a vertical axis augmented wind turbine: A two-dimensional study. J Wind Eng Ind Aerodyn 125: 168-179.    

16. Liu Y, Yoshida S (2015) An extension of the generalized actuator disc theory for aerodynamic analysis of the diffuser-augmented wind turbines. Energy 93: 1852-1859.    

17. Hansen MOL, Sørensen NN, Flay RGJ (2000) Effect of placing a diffuser around a wind turbine. Wind Energy 3: 207-213.    

18. Van Bussel GJW (2007) The science of making more torque from wind: diffuser experiments and theory revisited. J Phys Conf Ser 75: 1-12.    

19. Kosasih B, Saleh Hudin H (2016) Influence of inflow turbulence intensity on the performance of bare and diffuser-augmented micro wind turbine model. Renew Energy 87: 154-167.    

20. Lubitz WD, Shomer A (2014) Wind loads and efficiency of a diffuser augmented wind turbine ( DAWT). Proc Can Soc Mech Eng Int Congr 2014: 1-5.

21. Kesby JE, Bradney DR, Clausen PD (2016) Determining diffuser augmented wind turbine performance using a combined CFD/BEM method. J Phys Conf Ser 753.

22. Vaz JRP, Wood DH (2018) Effect of the diffuser efficiency on wind turbine performance. Renew Energy 126: 969-977.    

23. Kannan TS, Mutasher SA, Lau YHK (2013) Design and flow velocity simulation of diffuser augmented wind turbine using CFD. J Eng Sci Technol 8: 372-384.

24. Shikha S, Bhatti TS, Kothari DP (2005) Air concentrating nozzles: a promising option for wind turbines. Int J Energy Technol Policy 3: 394-412.    

25. Sivasegaram S (1986) Power augmentation in wind rotors: a review. Wind Eng 10: 163-179.

26. Anzai A, Nemoto Y, Ushiyama I (2004) Wind tunnel analysis of concentrators for augmented wind turbines. Wind Eng 28: 605-614.    

27. Rus LF (2012) Experimental study on the increase of the efficiency of vertical axis wind turbines by equipping them with wind concentrators. J Sustain Energy 3: 30-35.

28. Michał L, MacIej K, Jakub M, et al. (2016) Numerical simulation methodologies for design and development of diffuser-augmented wind turbines-analysis and comparison. Open Eng 6: 235-240.

29. El-Zahaby AM, Kabeel AE, Elsayed SS, et al. (2017) CFD analysis of flow fields for shrouded wind turbine's diffuser model with different flange angles. Alexandria Eng J 56: 171-179.    

30. Ohya Y, Karasudani T (2010) A shrouded wind turbine generating high output power with wind-lens technology. Energies 3: 634-649.    

31. Abe KI, Ohya Y (2004) An investigation of flow fields around flanged diffusers using CFD. J Wind Eng Ind Aerodyn 92: 315-330.    

32. Mansour K, Meskinkhoda P (2014) Computational analysis of flow fields around flanged diffusers. J Wind Eng Ind Aerodyn 124: 109-120.    

33. Srikanth KS, Tushar (2016) Numerical analysis of wind lens. Int J Innov Res Sci Eng Technol 5: 759-764.

34. Wang W-Q, Song K, Yan Y (2019) Influence of interaction between the diffuser and rotor on energy harvesting performance of a micro-diffuser-augmented hydrokinetic turbine. Ocean Eng 189: 106293.    

35. Göltenbott U, Ohya Y, Yoshida S, et al. (2017) Aerodynamic interaction of diffuser augmented wind turbines in multi-rotor systems. Renew Energy 112: 25-34.    

36. Yunus A (2010) Fluid mechanics fundamentals and applications, Boston, Tata McGraw Hill Education Private Limited.

37. Owisa F, Badawyb MTS, Abedb KA, et al. (2015) Numerical investigation of loaded and unloaded diffuser equipped with a flange. Int J Sci Eng Res 6: 312-341.

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