Effect of Chord Length on the Aerodynamic Performance of VAWTs with NACA 0015 Airfoil at Low Wind Speeds.
DOI:
https://doi.org/10.33003/fjorae.2025.0201.05Keywords:
Wind Energy,, VAWT,, Aerodynamic performance,, TSR,, CFD,, Chord length.Abstract
The aerodynamic performance of Vertical Axis Wind Turbines (VAWTs) in low-wind regions is strongly influenced by blade geometry, with chord length playing a key role in optimizing energy capture. Despite their low performance challenges, VAWTs remain a viable option for harnessing wind energy in urban and low-wind-speed environments. The NACA 0015 airfoil has been widely recommended by many studies for its effectiveness under such conditions. However, few studies have specifically investigated the impact of chord length on the performance of VAWTs using the NACA 0015 airfoil, despite numerous optimization efforts. This study investigates the influence of blade chord length on the aerodynamic performance of VAWT employing the NACA 0015 airfoil under low wind speed conditions, specifically 3m/s and 4m/s. Using 2D transient CFD simulations with the SST k-ω turbulence model, three chord lengths (0.1 m, 0.2 m, and 0.3 m) were assessed over a Tip Speed Ratio (TSR) range of 2.0 to 4.5. The findings from this study showed that chord length plays a dominant role in the performance of a VAWT in low wind regimes. While the configuration with 0.1m chord length generated the maximum power coefficient (Cp) of 0.395 during the 4m/s wind speed, the 0.2m chord length configuration produced a more stable performance with a peak Cp of 0.371. At a wind speed of 3m/s, the configuration with 0.3m chord length displayed signs of deteriorating performance due to an excessive increase in solidity. The findings provide insight into optimal chord sizing for small-scale VAWTs operating in urban low-wind environments, supporting design decisions for decentralized wind energy systems.
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