Experimental Studies of Turbulent Intensity around a Tidal Turbine Support Structure

Tidal stream energy is a low-carbon energy source. Tidal stream turbines operate in a turbulent environment, and the effect of the structure between the turbine and seabed on this environment is not fully understood. An experimental study using 1:72 scale models based on a commercial turbine design...

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Main Authors: Stuart Walker, Lorenzo Cappietti
Format: Article
Language:English
Published: MDPI AG 2017-04-01
Series:Energies
Subjects:
Online Access:http://www.mdpi.com/1996-1073/10/4/497
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author Stuart Walker
Lorenzo Cappietti
author_facet Stuart Walker
Lorenzo Cappietti
author_sort Stuart Walker
collection DOAJ
description Tidal stream energy is a low-carbon energy source. Tidal stream turbines operate in a turbulent environment, and the effect of the structure between the turbine and seabed on this environment is not fully understood. An experimental study using 1:72 scale models based on a commercial turbine design was carried out to study the support structure influence on turbulent intensity around the turbine blades. The study was conducted using the wave-current tank at the Laboratory of Maritime Engineering (LABIMA), University of Florence. A realistic flow environment (ambient turbulent intensity = 11%) was established. Turbulent intensity was measured upstream and downstream of a turbine mounted on two different support structures (one resembling a commercial design, the other the same with an additional vertical element), in order to quantify any variation in turbulence and performance between the support structures. Turbine drive power was used to calculate power generation. Acoustic Doppler velocimetry (ADV) was used to record and calculate upstream and downstream turbulent intensity. In otherwise identical conditions, performance variation of only 4% was observed between two support structures. Turbulent intensity at 1, 3 and 5 blade diameters, both upstream and downstream, showed variation up to 21% between the two cases. The additional turbulent structures generated by the additional element of the second support structure appears to cause this effect, and the upstream propagation of turbulent intensity is believed to be permitted by surface waves. This result is significant for the prediction of turbine array performance.
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spelling doaj.art-a746eb96ed4b499cb91ccfb3d97eee402022-12-22T02:20:04ZengMDPI AGEnergies1996-10732017-04-0110449710.3390/en10040497en10040497Experimental Studies of Turbulent Intensity around a Tidal Turbine Support StructureStuart Walker0Lorenzo Cappietti1Department of Mechanical Engineering, University of Sheffield, Sheffield S1 3JD, UKDipartimento di Ingegneria Civile e Ambientale, Università degli Studi di Firenze, 50139 Firenze, ItalyTidal stream energy is a low-carbon energy source. Tidal stream turbines operate in a turbulent environment, and the effect of the structure between the turbine and seabed on this environment is not fully understood. An experimental study using 1:72 scale models based on a commercial turbine design was carried out to study the support structure influence on turbulent intensity around the turbine blades. The study was conducted using the wave-current tank at the Laboratory of Maritime Engineering (LABIMA), University of Florence. A realistic flow environment (ambient turbulent intensity = 11%) was established. Turbulent intensity was measured upstream and downstream of a turbine mounted on two different support structures (one resembling a commercial design, the other the same with an additional vertical element), in order to quantify any variation in turbulence and performance between the support structures. Turbine drive power was used to calculate power generation. Acoustic Doppler velocimetry (ADV) was used to record and calculate upstream and downstream turbulent intensity. In otherwise identical conditions, performance variation of only 4% was observed between two support structures. Turbulent intensity at 1, 3 and 5 blade diameters, both upstream and downstream, showed variation up to 21% between the two cases. The additional turbulent structures generated by the additional element of the second support structure appears to cause this effect, and the upstream propagation of turbulent intensity is believed to be permitted by surface waves. This result is significant for the prediction of turbine array performance.http://www.mdpi.com/1996-1073/10/4/497marine energytidal turbinehorizontal-axis marine current turbineocean current turbineturbulencesupport structuredevice wake
spellingShingle Stuart Walker
Lorenzo Cappietti
Experimental Studies of Turbulent Intensity around a Tidal Turbine Support Structure
Energies
marine energy
tidal turbine
horizontal-axis marine current turbine
ocean current turbine
turbulence
support structure
device wake
title Experimental Studies of Turbulent Intensity around a Tidal Turbine Support Structure
title_full Experimental Studies of Turbulent Intensity around a Tidal Turbine Support Structure
title_fullStr Experimental Studies of Turbulent Intensity around a Tidal Turbine Support Structure
title_full_unstemmed Experimental Studies of Turbulent Intensity around a Tidal Turbine Support Structure
title_short Experimental Studies of Turbulent Intensity around a Tidal Turbine Support Structure
title_sort experimental studies of turbulent intensity around a tidal turbine support structure
topic marine energy
tidal turbine
horizontal-axis marine current turbine
ocean current turbine
turbulence
support structure
device wake
url http://www.mdpi.com/1996-1073/10/4/497
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