Spatial integration effect on velocity spectrum: Towards an interpretation of the − 11/3 power law observed in the spectra of turbine outputs
| Autor: | Benoît Gaurier, Philippe Druault, Grégory Germain |
|---|---|
| Přispěvatelé: | Institut Jean Le Rond d'Alembert (DALEMBERT), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER) |
| Jazyk: | angličtina |
| Rok vydání: | 2022 |
| Předmět: |
Inertial frame of reference
020209 energy 02 engineering and technology power spectral density 01 natural sciences Power law Turbine 010305 fluids & plasmas Physics::Fluid Dynamics Wind and tidal turbines Power spectral density 0103 physical sciences 0202 electrical engineering electronic engineering information engineering Scaling Physics [PHYS]Physics [physics] Renewable Energy Sustainability and the Environment Turbulence turbulence Spectral density Power law decay spectra Mechanics wind and tidal turbines Power (physics) Vector field power law decay spectra |
| Zdroj: | Renewable Energy (0960-1481) (Elsevier BV), 2022-01, Vol. 181, P. 1062-1080 Renewable Energy Renewable Energy, Elsevier, 2021, 181, pp.1062-1080. ⟨10.1016/j.renene.2021.09.106⟩ |
| ISSN: | 0960-1481 1879-0682 |
| DOI: | 10.1016/j.renene.2021.09.106⟩ |
| Popis: | International audience; To improve the turbine operational life, the interaction between flow properties and turbine performance needs to be elucidated. We then propose to examine the physical origin of the power-law scaling in the inertial range of turbine power outputs by experimentally exploring the spectral content of a 1:20 scaled model of a three-bladed horizontal-axis turbine positioned in a 3D turbulent flow. First, measurements confirm that the turbine power frequency spectra exhibit a power law decay proportional to −11/3 in the inertial range. Knowing that the turbine power fluctuations are linearly dependent on the incoming velocity fluctuations, PIV measurements are carried out to study the effect of the spatially integrated velocity onto its resulted spectrum. It is demonstrated that in inhomogeneous anisotropic turbulent flow, the velocity spectrum of its spatial average along N direction(s) has an inertial slope of −5/3 − 2N/3. This information is used to physically interpret the power-law scaling in the inertial range of the turbine power spectra. The previously observed f −11/3 scaling results from a 2D-spatial average velocity field coupled with a spectral average over blades. This physical explanation confirms previous works in which a transfer function was developed between incoming turbulence and the turbine power outputs. |
| Databáze: | OpenAIRE |
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