Showing papers on "Tip-speed ratio published in 1981"
01 Jan 1981
TL;DR: The SWT-3 wind turbine as mentioned in this paper is a microprocessor controlled three bladed variable speed upwind machine with a 3MW rating that is presently operational and undergoing system testing, and the tower, a rigid triangular truss configuration, is rotated about its vertical axis to position the wind turbine into the prevailing wind.
Abstract: The SWT-3 wind turbine, a microprocessor controlled three bladed variable speed upwind machine with a 3MW rating that is presently operational and undergoing system testing, is discussed. The tower, a rigid triangular truss configuration, is rotated about its vertical axis to position the wind turbine into the prevailing wind. The blades rotate at variable speed in order to maintain an optimum 6 to 1 tip speed ratio between cut in and fated wind velocity, thereby maximizing power extraction from the wind. Rotor variable speed is implemented by the use of a hydrostatic transmission consisting of fourteen fixed displacement pumps operating in conjunction with eighteen variable displacement motors. Full blade pitch with on-off hydraulic actuation is used to maintain 3MW of output power.
11 citations
01 May 1981
TL;DR: In this article, the aerodynamic decay of a wake from a high performance vertical axis wind turbine was investigated in a Boundary Layer wind tunnel. And the results indicated that the wind turbine should be spaced at least forty diameters apart to avoid mutual power depreciation greater than ten per cent.
Abstract: The theory and experimental measurements on the aerodynamic decay of a wake from high performance vertical axis wind turbine are discussed. In the initial experimental study, the wake downstream of a model Darrieus rotor, 28 cm diameter and a height of 45.5 cm, was measured in a Boundary Layer Wind Tunnel. The wind turbine was run at the design tip speed ratio of 5.5. It was found that the wake decayed at a slower rate with distance downstream of the turbine, than a wake from a screen with similar troposkein shape and drag force characteristics as the Darrieus rotor. The initial wind tunnel results indicated that the vertical axis wind turbines should be spaced at least forty diameters apart to avoid mutual power depreciation greater than ten per cent.
2 citations
01 Jan 1981
TL;DR: In this paper, a straight-bladed vertical-axis wind turbine has been constructed at Napier College and used as a test bed in order to test various blade configurations and electrical generator load systems.
Abstract: A straight-bladed vertical-axis wind turbine has been constructed at Napier College. The installation has been designed as a test bed in order to test various blade configurations and electrical generator load systems. The turbine has been placed on a test site and will be tested over the next two years. Available evidence has shown that the line of investigation should include a low aspect ratio, high solidity configuration and electrical power take-off to naturally match the turbine and supply a variety of load requirements.
2 citations
01 Jun 1981
TL;DR: In this article, a low power dynamometer is described for measuring the power and torque output from a two-bladed model wind turbine, and performance characteristics relating coefficient of performance to tip speed ratio and blade geometric pitch are presented for three designs of blade.
Abstract: The performance characteristics of wind turbines should be thoroughly investigated prior to expending large amounts of capital on a prototype design. A low power dynamometer is described for measuring the power and torque output from a two-bladed model wind turbine, and performance characteristics relating coefficient of performance to tip speed ratio and blade geometric pitch are presented for three designs of blade.
1 citations