Wind Tunnel Study on Wake Instability of Twin H-Rotor Vertical-Axis Turbines

Kun Wang, Li Zou, Aimin Wang, Peidong Zhao and Yichen Jiang
Additional contact information
Kun Wang: School of Naval Architecture, Dalian University of Technology, Dalian 116024, China
Li Zou: School of Naval Architecture, Dalian University of Technology, Dalian 116024, China
Aimin Wang: School of Naval Architecture, Dalian University of Technology, Dalian 116024, China
Peidong Zhao: School of Naval Architecture, Dalian University of Technology, Dalian 116024, China
Yichen Jiang: School of Naval Architecture, Dalian University of Technology, Dalian 116024, China

Energies, 2020, vol. 13, issue 17, 1-18

Abstract: In recent years, the H-rotor vertical-axis turbine has attracted considerable attention in the field of wind and tidal power generation. After a series of complex spatiotemporal evolutions, the vortex shed from turbine blades forms a turbulent wake with a multi-scale coherent structure. An analysis of the wake characteristics of twin turbines forms the basis of array optimisation. This study aimed to examine the instability characteristics of a twin-turbine wake with two rotational configurations. The dynamic evolution characteristics of coherent structures with different scales in the wake were analysed via wavelet analysis. The results show that an inverse energy cascade process occurs after the high-frequency small-scale coherent structures induced by rotation lose their coherence. This self-organising characteristic is more apparent in the quasi two-dimensional wake of a forward-moving counter-rotating turbine (Array 1) than in that of a backward-moving counter-rotating turbine (Array 2). With greater organisation and coherence, the wake of Array 1 exhibits low-frequency instability characteristics dominated by a large-scale coherent structure. In addition, the signals reconstructed using wavelet transform show that asymmetric modes exist between low-frequency large-scale coherent structures. The experimental results provide a new perspective on the instability mechanism of twin-turbine wakes, as well as important data for numerical modelling.

Keywords: twin H-rotor vertical-axis turbines; wake; instability; wavelet transform (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: 2020
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (1)

Downloads: (external link)
https://www.mdpi.com/1996-1073/13/17/4310/pdf (application/pdf)
https://www.mdpi.com/1996-1073/13/17/4310/ (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:13:y:2020:i:17:p:4310-:d:401367

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 ().