Underwater LED-based Lagrangian particle tracking velocimetry

Viola, Ignazio Maria; Nila, Alex; Davey, Thomas; Gabl, Roman

doi:10.1007/s12650-022-00832-z

Cited by 5 publications

(1 citation statement)

References 38 publications

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“…The model-scale tidal turbine used in this experimental campaign is a 1:15 scale model of the Tidal Generation Ltd. (now SABELLA) 1 MW tidal turbine, and is thus representative of a typical tidal turbine geometry. The drivetrain is the same used by, for instance, Payne et al (2017) and Viola et al (2022a). It has a rotor diameter D of 1.2 m with the blades mounted on a hub of diameter D hub of 0.12 m; this results in a diameter-based Reynolds number Re D of 9.8 × 10 5 , defined as…”

Section: Facility and Turbine Geometrymentioning

confidence: 99%

Model-scale experiments of passive pitch control for tidal turbines

Gambuzza¹,

Pisetta²,

Davey³

et al. 2022

Preprint

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Tidal currents are renewable and predictable energy sources that could prove fundamental to decrease dependency from fossil fuels. Tidal currents, however, are highly unsteady and non uniform, resulting in undesirable load fluctuations on the blades and the drive train of turbines. A passive morphing blade concept capable to reduce the load fluctuations without affecting the mean loads has recently been formulated and demonstrated with numerical simulations (Pisetta et al., 2022). In this paper, we present the first demonstration of this morphing blade concept, through experimental tests on a 1.2-m diameter turbine. We show that fluctuations in the root-bending moment, thrust and torque are consistently reduced over a broad range of tip-speed ratios. This work also highlights some critical design aspects of morphing blades. For instance, it is showed that the friction resistance can substantially decrease the effectiveness of the system and thus must be minimised by design. Overall this paper demonstrates for the first time the effectiveness of morphing blades for tidal turbines, paving the way to the future development of this technology.

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Section: Facility and Turbine Geometrymentioning

confidence: 99%

Model-scale experiments of passive pitch control for tidal turbines

Gambuzza¹,

Pisetta²,

Davey³

et al. 2022

Preprint

Self Cite

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Volumetric wake investigation of a free-flying quadcopter using Shake-The-Box Lagrangian particle tracking

Wolf,

Schanz,

Schwarz

et al. 2024

Exp Fluids

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The Shake-The-Box technique was applied to experimentally quantify the time-resolved volumetric flow field around a free-flying quadcopter UAV with an overall span of about 0.5 m. State-of-the-art LED illumination and high-speed camera equipment was combined with modern Lagrangian tracer particle tracking and data assimilation techniques, facilitating a measurement volume larger than $${1.5}\,{\hbox {m}^3}$$ 1.5 m 3 . The setup allowed for both hover and limited maneuvering of the quadcopter, while resolving even small details of the complex interactional aerodynamics. In hover out of ground effect, the four individual rotor wakes merged into a single jet within a few rotor radii below the rotor planes. Evaluating the mass and momentum fluxes over suitable control volumes yields accurate estimates for the quadcopter’s total thrust, the asymmetric thrust distribution between front and back rotors, and the entrainment of external flow through turbulent mixing. Hover in ground effect decreases the power requirement and induces recirculating flow in the center of the four rotors. The outwash pattern is non-uniform with jets developing between the rotors and pointing in radially outward directions. Forward flight cases result in a skewed, rapidly merging wake flanked by the roll-up of two “supervortices” similar to the wingtip vortices of fixed-wing vehicles.

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