Operational parameters of horizontal axis marine current turbines
Operational parameters of horizontal axis marine current turbines
This work presents an investigation into the design and operational issues of horizontal axis marine current turbines (MCTs). Recommendations for design of full-scale devices have been made from the use of numerical modelling. Results of this include the hydrodynamic performance of suitable rotor blade sections and their susceptibility to cavitation. Compromises for design are discussed based upon the relative merits of various aerofoil characteristics. A 1/30th scale model was designed and tested in a circulating water channel. This work identified several issues associated with operation at high blade inflow angles. The first was increased power production above prediction. The nature of this increase was unsteady and no relationship could be found based upon device and general flow conditions. The second issue was that of cavitation and an associated transient vibration loading upon the model. The inception of cavitation on the model MCT was used to validate part of the numerical modelling that suggests a full-scale, pre-cavitation blade speeds can be greater than previously thought. Both the excess power generation and cavitation at high blade inflow angles will have implications for stall-regulated MCTs. Observation of the water surface profile around the model MCT has lead to the determination of appropriate hydraulic parameters that could help characterise the operation of the device. The analysis indicates that at full scale, changes in water surface elevation will occur and will affect device design and the conditions at the site. A model based on general momentum theory was developed to predict the downstream centreline velocity deficit which showed good correlation with measured values from the model MCT.
University of Southampton
Myers, Luke E
ab4a390c-ea48-43bb-bfd5-532b52fd1556
2005
Myers, Luke E
ab4a390c-ea48-43bb-bfd5-532b52fd1556
Myers, Luke E
(2005)
Operational parameters of horizontal axis marine current turbines.
University of Southampton, Doctoral Thesis.
Record type:
Thesis
(Doctoral)
Abstract
This work presents an investigation into the design and operational issues of horizontal axis marine current turbines (MCTs). Recommendations for design of full-scale devices have been made from the use of numerical modelling. Results of this include the hydrodynamic performance of suitable rotor blade sections and their susceptibility to cavitation. Compromises for design are discussed based upon the relative merits of various aerofoil characteristics. A 1/30th scale model was designed and tested in a circulating water channel. This work identified several issues associated with operation at high blade inflow angles. The first was increased power production above prediction. The nature of this increase was unsteady and no relationship could be found based upon device and general flow conditions. The second issue was that of cavitation and an associated transient vibration loading upon the model. The inception of cavitation on the model MCT was used to validate part of the numerical modelling that suggests a full-scale, pre-cavitation blade speeds can be greater than previously thought. Both the excess power generation and cavitation at high blade inflow angles will have implications for stall-regulated MCTs. Observation of the water surface profile around the model MCT has lead to the determination of appropriate hydraulic parameters that could help characterise the operation of the device. The analysis indicates that at full scale, changes in water surface elevation will occur and will affect device design and the conditions at the site. A model based on general momentum theory was developed to predict the downstream centreline velocity deficit which showed good correlation with measured values from the model MCT.
This record has no associated files available for download.
More information
Published date: 2005
Identifiers
Local EPrints ID: 465829
URI: http://eprints.soton.ac.uk/id/eprint/465829
PURE UUID: 4b38e170-bd16-4a19-afa3-7f81e7e74a91
Catalogue record
Date deposited: 05 Jul 2022 03:14
Last modified: 23 Jul 2022 02:17
Export record
Contributors
Author:
Luke E Myers
Download statistics
Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.
View more statistics