A reference database for the analysis of wind-farm wake recovery mechanisms in a large-eddy simulation framework, capping-inversion heights=1000 m, capping-inversion strength=5 K, free-atmosphere lapse rate=4 K/km

For a capping-inversion heights=1000 m, capping-inversion strength=5 K, free-atmosphere lapse rate=4 K/km, we present a suite of large-eddy simulations of a wind farm operating in conventionally neutral atmospheric boundary layers (CNBLs). A fixed 1.6 GW wind farm is considered for 40 different atmospheric stratification conditions to investigate effects on wind-farm efficiency and blockage, as well as related gravity-wave excitation. A tuned Rayleigh damping layer and a wave-free fringe region method (Lanzilao & Meyers, Bound. Layer Meteor. 186, 2023) are used to avoid spurious excitation of gravity waves, and a domain-size study is included to evaluate and minimize effects of artificial domain blockage. A fully neutral reference case is also considered, to distinguish between a case with hydrodynamic blockage only, and cases that include hydrostatic blockage excited by gravity waves. We discuss in detail the dependence of gravity-wave excitation, flow fields, and wind-farm blockage on capping-inversion height, strength and free-atmosphere lapse rate. In all cases, an unfavourable pressure gradient is present in front of the farm, and a favourable pressure gradient in the farm, with hydrostatic contributions arising from gravity waves at least an order of magnitude larger than hydrodynamic effects. Using respectively non-local and wake efficiencies nu_{nl} and nu_w (Allaerts & Meyers, Bound. Layer Meteor. 166, 2018), we observe a strong negative correlation between unfavourable upstream pressure rise and nu_{nl}, and a strong positive correlation between the favourable pressure drop in the farm and nu_w. Using a simplified linear gravity-wave model, we formulate a simple scaling for nu_{nl}/nu_w, which matches reasonably well with the LES results.

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Източник https://doi.org/10.48804/L45LTT
Версия 1.0
Автор L. Lanzilao, J. Meyers
Отговорник по поддръжка J. Meyers
Имейл на отговорник по поддръжка J. Meyers
Dataset subject Wind Farm,Wakes
External conditions Flat Terrain,offshore
Dataset variables wind_speed,wind_direction,air_temperature
Spatial Data
Schema Compliance