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| Titel |
In situ measurements of wind and current speed and relationship between output power and turbulence |
| VerfasserIn |
Olmo Duran Medina, François G. Schmitt, Alexei Sentchev, Rudy Calif |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250101732
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| Publikation (Nr.) |
 EGU/EGU2015-925.pdf |
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| Zusammenfassung |
| In a context of energy transition, wind and tidal energy are sources of clean energy with the
potential of partially satisfying the growing demand. The main problem of this
type of energy, and other types of renewable energy remains the discontinuity of
the electric power produced in different scales, inducing large fluctuations also
called intermittency. This intermittency of wind and tidal energy is inherent to the
turbulent nature of wind and marine currents. We consider this intermittent power
production in strong relation with the turbulent intermittency of the resource. The
turbulence theory is multifractal energy cascades models, a classic in physics of
turbulence.
From earlier studies in atmospheric sciences, we learn that wind speed and the aggregate
power output are intermittent and multifractal over a wide range of scales [Calif and Schmitt
2014]. We want to extend this study to a marine current turbine and compare the scaling
properties for those renewable energy sources.
We consider here coupling between simultaneous velocity time series and output power from
a wind turbine and a marine current turbine. Wind turbine data were obtained from Denmark
and marine current data from Western Scheldt, Belgium where a prototype of a vertical and
horizontal marine current turbines are tested. After an estimation of their Fourier density
power spectra, we study their scaling properties in Kolmogorov’s theory and the framework
of fully developed turbulence.
Hence, we employ a Hilbert-based methodology, namely arbitrary-order Hilbert
spectral analysis [Calif et al. 2013a, 2013b] to characterize the intermittent property
of the wind and marine current velocity in order to characterize the intermittent
nature of the fluid. This method is used in order to obtain the spectrum and the
corresponding power law for non-linear and non-stationary time series. The goal is to
study the non-linear transfer characteristics in a multi-scale and multi-intensity
framework. |
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