Abstract
This paper explores passive flow control via leading-edge (LE) slats to reduce the dynamic stall (DS) phenomenon and related blade-wake interaction in an H-Darrieus type vertical axis wind turbine (VAWT) operating under low wind speed conditions. A comprehensive 2D unsteady computational fluid dynamics (CFD) assessment has been carried out for the non-slatted baseline rotor and the advance slatted rotor (ASR) configurations. The unsteady Reynolds-averaged Navier-Stokes (URANS) approach with k-ω shear stress transport (SST) turbulence model and sliding mesh technique have been applied in Ansys Fluent. Optimum slat deflection angle δ has been evaluated using the single-blade oscillatory case with and without the LE slats. Results indicate a reduction in optimum δ from 16° at rated wind speed of 10 ms−1 to 12° for low wind speed operation at 5 ms−1. A significant increase in the maximum coefficient of lift CL,max by approximately 32% and a delay in stall angle of attack αmax by 3° is obtained with ASR configuration compared to the baseline. Further assessment of the ASR configuration on the three-blade rotatory case demonstrates an increase in the power coefficient CP by approximately 15% at the rated tip-speed ratio λ compared to the baseline.
Original language | English |
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Article number | 100748 |
Journal | Sustainable Energy Technologies and Assessments |
Volume | 40 |
Early online date | 6 Jun 2020 |
DOIs | |
Publication status | Published - 31 Aug 2020 |
Externally published | Yes |
Bibliographical note
Funding Information:The authors would like to acknowledge the technical support from industrial collaborator Aeolos Wind Energy Ltd and provision of the high-performance computational facility by USPCAS-E NUST to carry out the research. Authors also appreciate the U.S. Agency for International Development (USAID) for their financial support (Applied Research Grant ARG-X-001).
Publisher Copyright:
© 2020 Elsevier Ltd
Keywords
- Computational fluid dynamics
- Dynamic stall
- Leading-edge slat
- Passive flow control
- Vertical axis wind turbine
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- Energy Engineering and Power Technology