Turbulence Boosts Renewable Energy Efficiency by 12% in Experimental Study

Researchers at the University of Virginia conducted an experimental study on the effects of freestream turbulence on the performance of oscillating hydrofoil turbines in renewable energy applications. The study, published in the Journal of Renewable and Sustainable Energy, found that increased turbulence levels enhance power production by increasing heave velocities and vertical forces throughout one oscillation period.

Key Takeaways:

• The study demonstrated that turbulence intensity affects the performance of oscillating hydrofoil turbines, with an increase in turbulence levels enhancing power production by 12%.
• The most benefit was observed on the downstroke, where heave range/speed increased due to gravity and inertia.
• Hydrodynamic efficiency increased by up to 12% with an observed maximum value of 52%.
• The study used a semi-passive hydrofoil turbine, operating at chord-based Reynolds numbers ranging from 69,000 to 91,000, and turbulence intensity of approximately 5%.
• The researchers used a passive turbulence grid to create a nearly uniform turbulence intensity profile with a turbulent integral length scale of 0.01 m.

Statistics:

• Turbulence intensity of approximately 5%
• Reynolds numbers ranging from 69,000 to 91,000
• Hydrodynamic efficiency increased by up to 12% with an observed maximum value of 52%
• Turbulent integral length scale of 0.01 m
• Increased power production by 12%

Sources:

• Effects of Freestream Turbulence On Energy Harvesting of a Single Semi-passive Oscillating Hydrofoil. Journal of Renewable and Sustainable Energy, 2025; 17(5).
• Aip Publishing, 1305 Walt Whitman Rd, Ste 300, Melville, NY 11747-4501, USA (Journal of Renewable and Sustainable Energy - jrse.aip.org/)
• Michael Jeong, University of Virginia, Dept. of Mechanical and Aerospace Engineering, Charlottesville, VA 22903, United States.