Wave-current interactions in marine current turbines

Barltrop, Nigel; Varyani, K.S.; Grant, Andrew; Clelland, David; Pham, X.P.

doi:10.1243/14750902jeme45

Cited by 23 publications

(29 citation statements)

References 2 publications

(2 reference statements)

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“…The maximum scaled current speed would be 4m/s, which is significant for a suitable MCEC location; however it is significantly lower than the maximum current speed of 8.55m/s used in the experiments conducted by Barltrop [6]. High velocities tend to be used in turbine experiments because a low Reynolds number can degrade the dynamical properties of the airfoil and can be a source of irregularity between the experimental data and simulation data [6]. Laboratory experiments are useful for approximating these wave-current phenomena since little detailed knowledge exists for tidal energy sites since there has never before been the need for such data [5].…”

Section: Towing Tank Experimentsmentioning

confidence: 87%

“…The model turbine is a F roude scaled representation of a 16m diameter MCEC. The maximum scaled current speed would be 4m/s, which is significant for a suitable MCEC location; however it is significantly lower than the maximum current speed of 8.55m/s used in the experiments conducted by Barltrop [6]. High velocities tend to be used in turbine experiments because a low Reynolds number can degrade the dynamical properties of the airfoil and can be a source of irregularity between the experimental data and simulation data [6].…”

Section: Towing Tank Experimentsmentioning

confidence: 98%

“…When the effects of linear theory have been properly evaluated, the next phase of testing will be to verify findings using waves on a non-uniform current. Barltrop [6] showed that the bending moments at roots of MCEC blades were found to fluctuate significantly; 50% of the mean value for out-of-plane bending moments and 100% of the mean value for in-plane bending moments. This justifies the need for individual blade loading experiments.…”

Section: Further Workmentioning

confidence: 99%

“…At present, few experimental wave-current studies have been conducted in the presence of MCECs. One particular study combined Blade Element Momentum (BEM) theory for wind turbines and linear wave theory to predict rotor torque and thrust and to assess the influence of waves on t he dynamic properties of bending moments at the root of rotor blades [6]. The outcomes were limited, particularly those for the blade loading.…”

Section: Introductionmentioning

confidence: 99%

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Experimental and Numerical Results of Rotor Power and Thrust of a Tidal Turbine Operating at Yaw and in Waves

Galloway¹,

Myers²,

Bahaj³

2011

Linköping Electronic Conference Proceedings

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Little has been done to investigate the behaviour of Marine Current Energy Converters (MCECs) in unsteady flow caused by wave motion and yaw. The additional loading applied to the rotor through the action of waves and whilst operating at yaw could dictate the structural design of blades as well as the proximity to the water surface. The strongly bi-directional nature of the flow encountered at many tidal energy sites may lead to devices employing zero rotor yaw control. Subsequent reductions in device capital cost may outweigh reduced power production and increased dynamic loading for a rotor operating at yaw. The experiments presented in this paper were conducted using a 1/20th scale 3-bladed horizontal axis MCEC at a large towing tank facility. The turbine had the capability to measure thrust and torque via a custom waterproof dynamometer. A BEM (Blade Element Momentum) code developed within the university was modified to include wave and yaw, with a view to further understanding the primary loading upon the rotor and individual blades.

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Section: Towing Tank Experimentsmentioning

confidence: 87%

Section: Towing Tank Experimentsmentioning

confidence: 98%

Section: Further Workmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Experimental and Numerical Results of Rotor Power and Thrust of a Tidal Turbine Operating at Yaw and in Waves

Galloway¹,

Myers²,

Bahaj³

2011

Linköping Electronic Conference Proceedings

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“…In a real operating environment (as distinct from a towing tank), dynamic loading from velocity shear, rotor misalignment and water-borne turbulence must be considered. For rotors near the surface, waves may add a significant cyclic load [6]. Finally, blade/strut interaction will create a once-per-revolution perturbation.…”

Section: Blade Loads and Dynamic Effectsmentioning

confidence: 99%

Design and testing of a contra-rotating tidal current turbine

Clarke

Connor

Grant

et al. 2007

Proceedings of the Institution of Mechanical Engineers, Part A:

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A contra-rotating marine current turbine has a number of attractive features: near-zero reactive torque on the support structure, near-zero swirl in the wake, and high relative interrotor rotational speeds. Modified blade element modelling theory has been used to design and predict the characteristics of such a turbine, and a model turbine and test rig have been constructed. Tests in a towing tank demonstrated the feasibility of the concept. Power coefficients were very high for such a small model and in excellent agreement with predictions, confirming the accuracy of the computational modelling procedures.High-frequency blade loading data were obtained in the course of the experiments. These show the anticipated dynamic components for a contra-rotating machine. Flow visualisation of the wake verified the lack of swirl behind the turbine. A larger machine is presently under construction for sea trials.

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Development and validation of a computational model for design analysis of a novel marine turbine

2012

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The vast tidal and wave energy resources represent a potential to use marine energy systems to supply part of the global energy demand. However, there are many advances required to develop economic and reliable marine energy systems, which some of these advances can be achieved by using the existing knowledge and experience from offshore and wind energy industry. This research presents a novel marine energy system that integrates the concept of a vertical and horizontal axis wind turbines by combining a Darrieus and Wells type rotor. However, many other different concepts have been proposed, but models that account for hydrodynamic, structure and control are needed to determine their technical and economical feasibility. With the use of the double-multiple streamtube theory, a hydrodynamic model is developed to predict the performance and the loads on the turbine blades coupled with a finite element model to compute strains and stresses. To validate the model, we used strain data from field measurement of the demo prototype. The validated model was used to compute extreme stresses and calculate the fatigue life. The model gives reliable estimates of stresses and fatigue life. With this result, the design analysis of the turbine blades can be optimized for any site condition and expected life time.

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Wave-current interactions in marine current turbines

Cited by 23 publications

References 2 publications

Experimental and Numerical Results of Rotor Power and Thrust of a Tidal Turbine Operating at Yaw and in Waves

Experimental and Numerical Results of Rotor Power and Thrust of a Tidal Turbine Operating at Yaw and in Waves

Design and testing of a contra-rotating tidal current turbine

Development and validation of a computational model for design analysis of a novel marine turbine

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