Cross-Flow Tidal Turbines with Highly Flexible Blades—Experimental Flow Field Investigations at Strong Fluid–Structure Interactions

Hoerner, Stefan; Kösters, Iring; Vignal, Laure; Cleynen, Olivier; Abbaszadeh, Shokoofeh; Maı̂tre, Thierry; Thévenin, Dominique

doi:10.3390/en14040797

Cited by 10 publications

(4 citation statements)

References 31 publications

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“…This led to a final temporal resolution of 1 kHz. Further details of the method are provided in Hoerner et al 2021. The resulting flow fields of size i, j were presented dimensionless by the velocities relative to the mean flow speed v of the entire measurement take.…”

Section: Particle Image Velocimetrymentioning

confidence: 99%

Passive flow control mechanisms with bioinspired flexible blades in cross-flow tidal turbines

et al. 2021

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State-of-the-art technologies for wind and tidal energy exploitation focus mostly on axial turbines. However, cross-flow hydrokinetic tidal turbines possess interesting features, such as higher area-based power density in array installations and shallow water, as well as a generally simpler design. Up to now, the highly unsteady flow conditions and cyclic blade stall have hindered deployment at large scales because of the resulting low single-turbine efficiency and fatigue failure challenges. Concepts exist which overcome these drawbacks by actively controlling the flow, at the cost of increased mechatronical complexity. Here, we propose a bioinspired approach with hyperflexible turbine blades. The rotor naturally adapts to the flow through deformation, reducing flow separation and stall in a passive manner. This results in higher efficiency and increased turbine lifetime through decreased structural loads, without compromising on the simplicity of the design. Graphic abstract

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Section: Particle Image Velocimetrymentioning

confidence: 99%

Passive flow control mechanisms with bioinspired flexible blades in cross-flow tidal turbines

et al. 2021

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“…Oceanic currents are an unexploited source of green energy with great potential and could seriously strengthen energy security. Hoerner et al [28] experimented with hydrokinetic vertical-axis or cross-flow tidal turbine (CFTT) morphing blades. They concluded that the flexibility of the camber-morphing airfoil has a significant impact on the wake structure and allows less accidental wake changes over time.…”

Section: Introductionmentioning

confidence: 99%

Aerodynamic Analysis of Variable Camber-Morphing Airfoils with Substantial Camber Deflections

Marciniuk,

Piskur,

Kiszkowiak

et al. 2024

Energies

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In recent years, morphing wings have become not only a concept, but an aerodynamic solution for the aviation industry to take a step forward toward future technologies. However, continuously morphing airfoils became an interesting answer to provide green energy solutions. In this paper, the authors conducted experimental research on a continuously camber-morphing airfoil using the Particle Image Velocimetry (PIV) and Computational Fluid Dynamics (CFD) methods. The main objective of this work was to research a variety of morphing airfoils with different camber deflections. An average velocity distribution and turbulence distribution were compared and are discussed. The two-dimensional PIV results were compared to the CFD simulations to validate the numerical method’s accuracy and obtain the aerodynamic coefficient’s trends. A further comparison revealed that morphing airfoils have better aerodynamic performance than conventional airfoils for very low camber deflections and create substantial amounts of drag for significant camber deflections.

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“…The search for truly sustainable sources of energy has translated into renewed interest in low-power, low-impact small-scale hydraulic power devices. Those devices notably include devices that bypass traditional dam-based installations, whose biological and hydropower performance were investigated in recent research [1,2], as well as hydrokinetic turbines (e.g., [3,4]), which may be installed on floating or unchanneled installations. One type of hydrokinetic device that is of particular interest in this work is the free-stream water wheel.…”

Section: Introductionmentioning

confidence: 99%

Genetic Optimisation of a Free-Stream Water Wheel Using 2D Computational Fluid Dynamics Simulations Points towards Design with Fully Immersed Blades

et al. 2022

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A large-scale two-dimensional computational fluid dynamics study is conducted in order to maximise the power output and smoothness of power delivery of a free-stream water wheel, a low-impact hydropower device. Based on models and methods developed in previous research, the study uses a genetic algorithm to optimise the geometry of a wheel with a given radius and depth, maximising two objective functions simultaneously. After convergence and suitable post-processing, a single optimal design is identified, featuring eight shortened blades that become fully immersed at the nadir point. The design results in a 71% reduction in blade material and a 113% increase in the work ratio while improving the hydraulic power by 8% compared to the previous best design. These characteristics are applied retroactively to a broad family of designs, resulting in significant improvements in performance. Analysis of the resulting designs indicates that when either the hydraulic power coefficient, rotor power coefficient, or work ratio is considered, free-stream water wheels with fully immersed blades, whose power mechanisms are shown to rely on lift, as well as drag, outperform all other designs studied so far.

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Cross-Flow Tidal Turbines with Highly Flexible Blades—Experimental Flow Field Investigations at Strong Fluid–Structure Interactions

Cited by 10 publications

References 31 publications

Passive flow control mechanisms with bioinspired flexible blades in cross-flow tidal turbines

Passive flow control mechanisms with bioinspired flexible blades in cross-flow tidal turbines

Aerodynamic Analysis of Variable Camber-Morphing Airfoils with Substantial Camber Deflections

Genetic Optimisation of a Free-Stream Water Wheel Using 2D Computational Fluid Dynamics Simulations Points towards Design with Fully Immersed Blades

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