Application of hybrid Darrieus–Savonius turbines with dimpled blades at the offshore platform for sustainable energy
Mohammed ALAVI, Ahmad AL RAMAHI, Hasan HAMDAN, Sharul Sham DOL
Abstract. In support with Abu Dhabi 2050 Vision to become carbon neutral and a world leader in renewable energy, this research examines the use of hybrid Vertical Axis Wind Turbine (VAWT) with surface dimples for offshore energy generation. The simulation phase utilized ANSYS Fluent with a k-ω SST turbulence model to assess aerodynamic behavior across traditional H-rotor, hybrid, and dimple-enhanced configurations. Conducted at wind velocities from 3 to 10 m/s and rotational speeds of 250 and 300 RPM, results showed that the dimpled hybrid turbine achieved superior performance metrics—reducing turbulent kinetic energy by up to 45%, delaying flow separation, and improving wake stability. These improvements directly contributed to higher lift-to-drag ratios and smoother airflow around the blades, particularly under rotational conditions typical of offshore environments. Parallel experimental tests involved a modular VAWT hybrid turbine equipped with adjustable turbine dimensions and NACA 0021 blades featuring circular dimples (10 mm diameter, 4 mm depth, Dimple Ratio = 0.4). Under a controlled wind speed of 7.5 m/s, the optimal setup (2.5 m height, 1 m width) achieved a daily energy output of 7.4 kWh and a peak performance coefficient (Cp) reaching 27.5% of Betz’s theoretical limit. Smoke visualization confirmed the improved flow attachment and delayed boundary layer detachment over dimpled surfaces, consistent with the CFD findings.
Keywords
CFD, Darrieus Turbine, Dimpled Surface, Hybrid Turbine, Offshore, Renewable, Savonius Turbine, Turbulent, Vertical Axis Wind Turbine
Published online 6/20/2026, 7 pages
Copyright © 2026 by the author(s)
Published under license by Materials Research Forum LLC., Millersville PA, USA
Citation: Mohammed ALAVI, Ahmad AL RAMAHI, Hasan HAMDAN, Sharul Sham DOL, Application of hybrid Darrieus–Savonius turbines with dimpled blades at the offshore platform for sustainable energy, Materials Research Proceedings, Vol. 67, pp 17-23, 2026
DOI: https://doi.org/10.21741/9781644904176-3
The article was published as article 3 of the book Climate Action and Sustainability
Content from this work may be used under the terms of the Creative Commons Attribution 3.0 license. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
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