Variable pitch darrieus water turbines
| dc.contributor.author | Kirke, Brian | en |
| dc.contributor.author | Lazauskas, Leo Victor | en |
| dc.contributor.school | School of Mathematical Sciences | en |
| dc.date.issued | 2008 | en |
| dc.description | Copyright © 2008 National Institute of Informatics. All Rights Reserved | en |
| dc.description.abstract | In recent years the Darrieus wind turbine concept has been adapted for use in water, either as a hydrokinetic turbine converting the kinetic energy of a moving fluid in open flow like an underwater wind turbine, or in a low head or ducted arrangement where flow is confined, streamtube expansion is controlled and efficiency is not subject to the Betz limit. Conventional fixed pitch Darrieus turbines suffer from two drawbacks, (i) low starting torque and (ii) shaking due to cyclical variations in blade angle of attack. Ventilation and cavitation can also cause problems in water turbines when blade velocities are high. Shaking can be largely overcome by the use of helical blades, but these do not produce large starting torque. Variable pitch can produce high starting torque and high efficiency, and by suitable choice of pitch regime, shaking can be minimized but not entirely eliminated. Ventilation can be prevented by avoiding operation close to a free surface, and cavitation can be prevented by limiting blade velocities. This paper summarizes recent developments in Darrieus water turbines, some problems and some possible solutions. | en |
| dc.description.statementofresponsibility | Kirke Brian amd Lazauskas Leo | en |
| dc.identifier.citation | Journal of Fluid Science and Technology, 2008; 3(2):430-438 | en |
| dc.identifier.issn | 1880-5558 | en |
| dc.identifier.uri | http://hdl.handle.net/2440/53710 | |
| dc.language.iso | en | en |
| dc.publisher | The Japan Society of Mechanical Engineers | en |
| dc.title | Variable pitch darrieus water turbines | en |
| dc.type | Journal article | en |