Coastal-zone wind energy. Part II. Frequency distribution of winds by direction for East and Gulf Coast stations

The present work aims to provide a comprehensive picture of the wind energy potential that characterizes the Romanian coastal environment using in situ measurements and reanalysis of wind data (ERA5) that cover a 42–year time interval (1979–2020). A total of 16 reference points (both land and offshore) equally distributed along the Romanian sector are used to evaluate the local wind energy potential, targeting in this way several sites where a renewable wind project could be established. Compared to the in situ measurements (land points), the ERA5 dataset underestimates the wind speed by at least 11.57%, this value increasing as we approach the coastline. From the analysis of the spatial maps, it is likely that the wind speed steadily increases from onshore to offshore, with a sharp variation near the coastline being reported. Furthermore, the assessment of some state-of-the-art offshore wind turbines was conducted using 12 systems defined by rated capacity ranging from 2 to 10 MW. Some scenarios were proposed to identify sustainable offshore wind projects to be implemented in the Romanian coastal zone based on these results.

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Wind speed frequency distribution modeling and wind energy resource assessment based on polynomial regression model

International Journal of Electrical Power & Energy Systems ◽

10.1016/j.ijepes.2021.106964 ◽

2021 ◽

Vol 130 ◽

pp. 106964

Author(s):

Lingzhi Wang ◽

Jun Liu ◽

Fucai Qian

Keyword(s):

Wind Speed ◽

Wind Energy ◽

Regression Model ◽

Frequency Distribution ◽

Polynomial Regression ◽

Energy Resource ◽

Resource Assessment ◽

Distribution Modeling ◽

Polynomial Regression Model

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PROBLEMS OF SEDIMENTS TRANSPORT MODELING IN THE COASTAL AREA

Journal of Oceanological Research ◽

10.29006/1564-2291.jor-2021.49(1).6 ◽

2021 ◽

Vol 49 (1) ◽

pp. 93-141

Author(s):

R. D. Kosyan ◽

B. V. Divinsky

Keyword(s):

Sediment Transport ◽

Surface Waves ◽

Wave Field ◽

Frequency Distribution ◽

Coastal Zone ◽

Bottom Sediments ◽

Wave Energy ◽

Laboratory Experiments ◽

Wind Waves ◽

Wave Spectrum

Due to the development of measuring instruments, a more detailed analysis of the wave field and the field of suspended sediments spatio-temporal characteristics has become possible. Through the efforts of Russian specialists over the past decades: A unique database of observations of the sediment movement in storm situations in different physical and geographical areas of the coastal zone of the Black, Baltic, North, Mediterranean, South China Seas has been collected, supplemented by extensive data of laboratory experiments in the best laboratory in Europe (Hannover, Germany). New experimental material has been obtained to determine the physical features of sediment transport by wave flow. The main mechanisms controlling the amplitude and phase relationships of the concentration fluctuations and discharge of suspended sediment on time scales less than the period of the peak of the wind wave spectrum are considered. The presence of low-frequency fluctuations in sediment concentration with a period of the order of several periods of wind waves and an amplitude several times higher than the average value of concentration is noted. The previously unexplored problem of the wave energy frequency distribution in the spectrum of surface waves influence on the sediment transport has been analyzed. Differences in the response of the washed-out bottom to an external disturbance, represented by irregular surface waves with constant integral characteristics (significant wave height and period of the spectrum peak) and variable wave energy frequency distribution, were revealed. The influence of swell waves on the redistribution of bottom sediments in the sea coastal zone was investigated. It is shown that dividing the wave field into separate components allows a more correct description of the spatiotemporal structure of surface waves, as well as a significant refinement of the bottom sediment transport schemes in the coastal zone. Using the example of the Anapa bay bar, it is shown that situations are possible in which the alongshore flow of bottom sediments is almost completely determined by swell waves. The results of field and laboratory experiments make it possible to determine the directions for further research on the creation of physically based models of sediment transport by waves and wave currents.

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