Characterizing the coherent structures in large eddy simulations of aligned windfarms

Wake Conference 2017

Zhang, Mengqi^1 ; Stevens, Richard J. A. M.^1

Department of Physics, Mesa+ Institute and J.M. Burgers, Centre for Fluid Dynamics, University of Twente, Enschede

7500AE, Netherlands^1

关键词: Coherent structure;    Counter rotating;    POD analysis;    POD modes;    Proper orthogonal decomposition method;    Streamwise directions;    Wind farm;    Work study;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/854/1/012052/pdf
DOI  :  10.1088/1742-6596/854/1/012052

来源: IOP

【 摘 要 】

The present work studies the large coherent structures in large eddy simulations of windfarms using proper orthogonal decomposition (POD) method. In order to evaluate the effect of wind turbines on coherent structures, we consider three cases. One is a reference flow of a neutral atmospheric boundary layer and the other two are periodic and developing aligned windfarms. The number of wind turbines is large, 16 × 12 for periodic windfarm, and 12 × 12 for developing windfarm. The simulations are run for a long time in order to generate a sufficient database for POD analysis. In all cases, elongated streamwise counter rotating roll structures, covering 1 or 2 turbines in spanwise direction, are identified as the dominant POD mode. Another pattern, varying in streamwise direction, also appears in all the three cases.