Sites for wind power installations: wind tunnel simulation of the influence of two-dimensional ridges on wind speed and turbulence: draft final report, second year
Date
1977-07
Authors
Meroney, Robert N., author
Sandborn, V. A., author
Bouwmeester, R. J. B., author
Rider, M. A., author
Fluid Mechanics and Wind Engineering Program, Civil Engineering Department, Colorado State University, publisher
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Journal ISSN
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Abstract
Wind tunnel studies of optimum sites for wind power turbines were made. A systematic evaluation of the flow over two-dimensional ridges is reported. Two-dimensional ridges with definite crests, such as ideal triangular or sinusoidal shapes, produce the greatest amplifications in local wind speed. Bluff, very steep and flat topped ridges do not produce as large an increase in velocity as the crest ridges. The ridges tested were of small characteristic size compared to the boundary layer thickness. The models correspond to ridges of the order of 100 meters or less in the atmosphere. For these ridges it is found that local viscous effects are of second order and the speedup of velocity can be predicted by inviscid flow considerations. Only near the surface (corresponding to approximately one to two ridge heights) are large changes in velocity observed. Wind velocity increases of the order of two times or greater than that of the approach velocity are measured at the crest of the triangular ridge. A slope of 1 to 4 (14 degrees) for the triangular ridge gives the optimum speedup at the crest. The flow in the outer region of the boundary layers over the ridge was found to remain similar to the flow upstream of the ridge. The longitudinal turbulent velocity component was found to decrease slightly near the ridge surface as the flow progressed over the windward face of the ridge. The vertical turbulent velocity component increased slightly along the windward face of the ridge. The variation in turbulent velocities over the windward face of the ridge correspond to effect of a contraction on isotropic turbulence.
Description
CER77-78RNM-VAS-RB-MAR6.
Includes bibliographical references (page 33).
Prepared for the United States Energy Research and Development Administration, Division of Solar Energy, Federal Wind Energy Program.
July 1977.
Includes bibliographical references (page 33).
Prepared for the United States Energy Research and Development Administration, Division of Solar Energy, Federal Wind Energy Program.
July 1977.
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Subject
Wind power