Abstract
Vertical Axis Wind Turbines (VAWTs) are omni-directional, low-cost, low-efficiency wind power extractors. A conventional drag-based VAWT consists of multiple thin rotor blades with a typical peak Tip Speed Ratio (λ) of < 1. Their lower cut-in speed and maintenance cost make them ideal for power generation in urban environments. Numerous studies have been carried out analysing steady operation of VAWTs and quantifying their performance characteristics, however, minimal attention has been paid to their start-up dynamics. There are a few recent studies in which start-up dynamics of lift-based VAWTs have been analysed but such studies for drag-based VAWTs are severely limited. In this study, start-up dynamics of a conventional multi-blade drag-based VAWT have been numerically investigated using a time-dependant Computational Fluid Dynamics (CFD) solver. In order to enhance the start-up characteristics of the drag-based VAWT, a stator has been integrated in the design assembly. The numerical results obtained in this study indicate that an appropriately designed stator can significantly enhance the start-up of a VAWT by directing the flow towards the rotor blades, leading to higher rotational velocity (ω) and λ. With the addition of a stator, the flow fields downstream the VAWT becomes more uniform.
Original language | English |
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Article number | 8135 |
Number of pages | 19 |
Journal | Energies |
Volume | 15 |
Issue number | 21 |
Early online date | 31 Oct 2022 |
DOIs | |
Publication status | Published - Nov 2022 |
Keywords
- Vertical Axis Wind Turbine (VAWT)
- Computational Fluid Dynamics (CFD)
- start-up dynamics
- dynamic meshing
- tip speed ratio
ASJC Scopus subject areas
- Control and Optimization
- Energy (miscellaneous)
- Engineering (miscellaneous)
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering
- Building and Construction
- Fuel Technology
- Renewable Energy, Sustainability and the Environment