scholarly journals Doppler Lidar–Based Wind-Profile Measurement System for Offshore Wind-Energy and Other Marine Boundary Layer Applications

2012 ◽  
Vol 51 (2) ◽  
pp. 327-349 ◽  
Author(s):  
Yelena L. Pichugina ◽  
Robert M. Banta ◽  
W. Alan Brewer ◽  
Scott P. Sandberg ◽  
R. Michael Hardesty

AbstractAccurate measurement of wind speed profiles aloft in the marine boundary layer is a difficult challenge. The development of offshore wind energy requires accurate information on wind speeds above the surface at least at the levels occupied by turbine blades. Few measured data are available at these heights, and the temporal and spatial behavior of near-surface winds is often unrepresentative of that at the required heights. As a consequence, numerical model data, another potential source of information, are essentially unverified at these levels of the atmosphere. In this paper, a motion-compensated, high-resolution Doppler lidar–based wind measurement system that is capable of providing needed information on offshore winds at several heights is described. The system has been evaluated and verified in several ways. A sampling of data from the 2004 New England Air Quality Study shows the kind of analyses and information available. Examples include time–height cross sections, time series, profiles, and distributions of quantities such as winds and shear. These analyses show that there is strong spatial and temporal variability associated with the wind field in the marine boundary layer. Winds near the coast show diurnal variations, and frequent occurrences of low-level jets are evident, especially during nocturnal periods. Persistent patterns of spatial variability in the flow field that are due to coastal irregularities should be of particular concern for wind-energy planning, because they affect the representativeness of fixed-location measurements and imply that some areas would be favored for wind-energy production whereas others would not.

Author(s):  
Georgios Deskos ◽  
Joseph C. Y. Lee ◽  
Caroline Draxl ◽  
Michael A. Sprague

AbstractWe present a review of existing wind-wave coupling models and parameterizations used for large-eddy simulation of the marine atmospheric boundary layer. The models are classified into two main categories: (i) the wave phaseaveraged, sea-surface-roughness models and (ii) the wave phase-resolved models. Both categories are discussed from their implementation, validity, and computational efficiency viewpoints with emphasis given on their applicability in offshore wind energy problems. In addition to the various models discussed, a review of laboratory-scale and field-measurement databases are presented thereafter. The majority of the presented data have been gathered over many decades of studying air-sea interaction phenomena, with the most recent ones compiled to reflect an offshore wind energy perspective. Both provide valuable data for model validation. Finally, we also discuss the modeling knowledge gaps and computational challenges ahead.


2017 ◽  
Vol 137 ◽  
pp. 497-504 ◽  
Author(s):  
Nihanth W. Cherukuru ◽  
Ronald Calhoun ◽  
Raghavendra Krishnamurthy ◽  
Svardal Benny ◽  
Joachim Reuder ◽  
...  

2014 ◽  
Vol 8 (01) ◽  
pp. 1 ◽  
Author(s):  
Grady J. Koch ◽  
Jeffrey Y. Beyon ◽  
Larry J. Cowen ◽  
Michael J. Kavaya ◽  
Michael S. Grant

2012 ◽  
Vol 6 (1) ◽  
pp. 063562-1 ◽  
Author(s):  
Grady J. Koch ◽  
Jeffrey Y. Beyon ◽  
Edward A. Modlin ◽  
Paul J. Petzar ◽  
Steve Woll ◽  
...  

2020 ◽  
Vol 8 (12) ◽  
pp. 999
Author(s):  
Yong Jun Cho

Even though the offshore wind industry’s growth potential is immense, the offshore wind industry is still suffering from problems, such as the large initial capital requirements. Many factors are involved, and among these, the extra costs incurred by the conservative design of offshore wind energy converters can be quickly addressed at the design stage by accounting for the nonlinear destructive interaction between wind and wave loads. Even when waves approach offshore wind energy converters collinearly with the wind, waves and wind do not always make the offshore wind energy converter’s substructure deformed. These environmental loads can intermittently exert a force of resistance against deformation due to the nonlinear destructive interaction between wind and wave loads. Hence, the nonlinear destructive interaction between wave and wind loads deserves much more attention. Otherwise, a very conservative design of offshore wind energy converters will hamper the offshore wind energy industry’s development, which is already suffering from enormous initial capital expenditures. In this rationale, this study numerically simulates a 5 MW offshore wind energy converter’s structural behavior subject to wind and random waves using the dynamic structural model developed to examine the nonlinear destructive interaction between wind and wave loads. Numerical results show that the randomly fluctuating water surface as the wind blows would restrict the offshore wind energy converter’s substructure’s deflection. Nonuniform growth of the atmospheric boundary layer due to the wavy motions at the water surface as the wind blows results in a series of hairpin vortices, which lead to the development of a large eddy out of hairpin vortices swirling in the direction opposite to the incoming wind near the atmospheric boundary layer. As a result, the vertical profile of the longitudinal wind velocity is modified; the subsequent energy loss drastically weakens the wind velocity, which consequently leads to the smaller deflection of the substructure of the offshore wind energy converter by 50% when compared with that in the case of wind with gusts over a calm sea.


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