On the Accuracy of Three-Dimensional Actuator Disc Approach in Modelling a Large-Scale Tidal Turbine in a Simple Channel
To date, only a few studies have examined the execution of the actuator disc approximation for a full-size turbine. Small-scale models have fewer constraints than large-scale models because the range of time-scale and length-scale is narrower. Hence, this article presents the methodology in implemen...
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MDPI AG
2018-08-01
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Series: | Energies |
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Online Access: | http://www.mdpi.com/1996-1073/11/8/2151 |
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author | Anas Rahman Vengatesan Venugopal Jerome Thiebot |
author_facet | Anas Rahman Vengatesan Venugopal Jerome Thiebot |
author_sort | Anas Rahman |
collection | DOAJ |
description | To date, only a few studies have examined the execution of the actuator disc approximation for a full-size turbine. Small-scale models have fewer constraints than large-scale models because the range of time-scale and length-scale is narrower. Hence, this article presents the methodology in implementing the actuator disc approach via the Reynolds-Averaged Navier-Stokes (RANS) momentum source term for a 20-m diameter turbine in an idealised channel. A structured grid, which varied from 0.5 m to 4 m across rotor diameter and width was used at the turbine location to allow for better representation of the disc. The model was tuned to match known coefficient of thrust and operational profiles for a set of validation cases based on published experimental data. Predictions of velocity deficit and turbulent intensity became almost independent of the grid density beyond 11 diameters downstream of the disc. However, in several instances the finer meshes showed larger errors than coarser meshes when compared to the measurements data. This observation was attributed to the way nodes were distributed across the disc swept area. The results demonstrate that the accuracy of the actuator disc was highly influenced by the vertical resolutions, as well as the grid density of the disc enclosure. |
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format | Article |
id | doaj.art-2092e9b0e549497688b9078ecd273332 |
institution | Directory Open Access Journal |
issn | 1996-1073 |
language | English |
last_indexed | 2024-04-11T22:09:40Z |
publishDate | 2018-08-01 |
publisher | MDPI AG |
record_format | Article |
series | Energies |
spelling | doaj.art-2092e9b0e549497688b9078ecd2733322022-12-22T04:00:35ZengMDPI AGEnergies1996-10732018-08-01118215110.3390/en11082151en11082151On the Accuracy of Three-Dimensional Actuator Disc Approach in Modelling a Large-Scale Tidal Turbine in a Simple ChannelAnas Rahman0Vengatesan Venugopal1Jerome Thiebot2Mechanical Engineering Programme, School of Mechatronic Engineering, University Malaysia Perlis, Pauh Putra Campus, Perlis 02600, MalaysiaInstitute for Energy Systems, School of Engineering, The University of Edinburgh, Edinburgh EH9 3DW, UKLaboratoire Universitaire des Sciences Appliquées de Cherbourg (LUSAC), Normandie Univ, UNICAEN, LUSAC, 14000 Caen, FranceTo date, only a few studies have examined the execution of the actuator disc approximation for a full-size turbine. Small-scale models have fewer constraints than large-scale models because the range of time-scale and length-scale is narrower. Hence, this article presents the methodology in implementing the actuator disc approach via the Reynolds-Averaged Navier-Stokes (RANS) momentum source term for a 20-m diameter turbine in an idealised channel. A structured grid, which varied from 0.5 m to 4 m across rotor diameter and width was used at the turbine location to allow for better representation of the disc. The model was tuned to match known coefficient of thrust and operational profiles for a set of validation cases based on published experimental data. Predictions of velocity deficit and turbulent intensity became almost independent of the grid density beyond 11 diameters downstream of the disc. However, in several instances the finer meshes showed larger errors than coarser meshes when compared to the measurements data. This observation was attributed to the way nodes were distributed across the disc swept area. The results demonstrate that the accuracy of the actuator disc was highly influenced by the vertical resolutions, as well as the grid density of the disc enclosure.http://www.mdpi.com/1996-1073/11/8/2151tidal energyactuator discturbulencewake analysisTelemac3D |
spellingShingle | Anas Rahman Vengatesan Venugopal Jerome Thiebot On the Accuracy of Three-Dimensional Actuator Disc Approach in Modelling a Large-Scale Tidal Turbine in a Simple Channel Energies tidal energy actuator disc turbulence wake analysis Telemac3D |
title | On the Accuracy of Three-Dimensional Actuator Disc Approach in Modelling a Large-Scale Tidal Turbine in a Simple Channel |
title_full | On the Accuracy of Three-Dimensional Actuator Disc Approach in Modelling a Large-Scale Tidal Turbine in a Simple Channel |
title_fullStr | On the Accuracy of Three-Dimensional Actuator Disc Approach in Modelling a Large-Scale Tidal Turbine in a Simple Channel |
title_full_unstemmed | On the Accuracy of Three-Dimensional Actuator Disc Approach in Modelling a Large-Scale Tidal Turbine in a Simple Channel |
title_short | On the Accuracy of Three-Dimensional Actuator Disc Approach in Modelling a Large-Scale Tidal Turbine in a Simple Channel |
title_sort | on the accuracy of three dimensional actuator disc approach in modelling a large scale tidal turbine in a simple channel |
topic | tidal energy actuator disc turbulence wake analysis Telemac3D |
url | http://www.mdpi.com/1996-1073/11/8/2151 |
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