Numerical Analysis of Effects of Arms with Different Cross-Sections on Straight-Bladed Vertical Axis Wind Turbine

Yutaka Hara, Naoki Horita, Shigeo Yoshida, Hiromichi Akimoto and Takahiro Sumi
Additional contact information
Yutaka Hara: Faculty of Engineering, Tottori University, 4-101 Koyama-Minami, Tottori 680-8552, Japan
Naoki Horita: Graduate School of Engineering, Tottori University, 4-101 Koyama-Minami, Tottori 680-8552, Japan
Shigeo Yoshida: Research Institute for Applied Mechanics, Kyushu University, 6-1 Kasugakoen, Kasuga, Fukuoka 816-8580, Japan
Hiromichi Akimoto: Graduate School of Engineering, Osaka University, Yamada-Oka, Suita, Osaka 565-0871, Japan
Takahiro Sumi: Faculty of Science and Engineering, Saga University, Honjo, Saga 840-8502, Japan

Energies, 2019, vol. 12, issue 11, 1-24

Abstract: Most vertical axis wind turbines (VAWTs) need arms connecting the blades with the rotational axis. The arms increase the power loss of VAWTs; however, the distribution between the pressure and friction influences and their degrees of influence have not yet been investigated in detail in past research. We applied computational fluid dynamics (CFD) targeting a small-sized straight-bladed VAWT to elucidate the effects of arms on turbine performance. In the analysis, three kinds of arms with different cross-sections (NACA 0018 airfoil, 18% rectangular, circular) with the same height were added to an armless rotor. The tangential forces and resistance torques caused by the added arms were recalculated by dividing the pressure and friction influences based on the surface pressure and friction distributions obtained by the CFD on an arm or a blade. The pressure-based tangential force of an arm, regardless of the cross-section, had a tendency to increase near the connection part between the arm and a blade. Though the value was small, the friction on the rectangular arm generated a driving force, whereas the friction on the other arms generated resistance forces. The pressure-based tangential force of a blade increased for a wide region around the connection part. The friction-based tangential force of a blade dropped around the connection part of every arm-equipped rotor. The arm resistance torque added to a VAWT by the existence of arms was larger than the added blade resistance torque in the cases of rectangular and circular arm rotors. Conversely, in the case of the airfoil arm rotor, the resistance torque added to blades became larger than that of arms.

Keywords: wind energy; vertical axis wind turbine; rotor arm; strut; surface pressure; surface friction; drag coefficient; computational fluid dynamics; dryland (search for similar items in EconPapers)
JEL-codes: Q Q0 Q4 Q40 Q41 Q42 Q43 Q47 Q48 Q49 (search for similar items in EconPapers)
Date: 2019
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (8)

Downloads: (external link)
https://www.mdpi.com/1996-1073/12/11/2106/pdf (application/pdf)
https://www.mdpi.com/1996-1073/12/11/2106/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jeners:v:12:y:2019:i:11:p:2106-:d:236419

Access Statistics for this article

Energies is currently edited by Ms. Agatha Cao

More articles in Energies from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().