Limitations to the validity of single wake superposition in wind farm yield assessment

WindEurope Summit 2016

Gunn, K.^1 ; Stock-Williams, C.^1 ; Burke, M.^1 ; Willden, R.^2 ; Vogel, C.^2 ; Hunter, W.^2 ; Stallard, T.^3 ; Robinson, N.^4 ; Schmidt, S.R.^5

Uniper Engineering, Technology Centre, Ratcliffe on Soar, Nottingham

NG11 OEE, United Kingdom^1

Department of Engineering Science, University of Oxford, OX1 3PJ, United Kingdom^2

School of Mechanical, Aerospace and Civil Engineering, University of Manchester, Manchester

M13 9PL, United Kingdom^3

AWS TruePower, 463 New Karner Road, Albany

NY

12205, United States^4

E.ON Climate and Renewables, Carl Gustafs väg 1, Malmö

SE-205 09, Sweden^5

关键词: Analytical modelling and simulations;    Assessment models;    Commercial models;    Flow physics;    Pressure field;    Wake-wake interactions;    Wind farm;    Yield prediction;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/749/1/012003/pdf
DOI  :  10.1088/1742-6596/749/1/012003

来源: IOP

【 摘 要 】

Commercially available wind yield assessment models rely on superposition of wakes calculated for isolated single turbines. These methods of wake simulation fail to account for emergent flow physics that may affect the behaviour of multiple turbines and their wakes and therefore wind farm yield predictions. In this paper wake-wake interaction is modelled computationally (CFD) and physically (in a hydraulic flume) to investigate physical causes of discrepancies between analytical modelling and simulations or measurements. Three effects, currently neglected in commercial models, are identified as being of importance: 1) when turbines are directly aligned, the combined wake is shortened relative to the single turbine wake; 2) when wakes are adjacent, each will be lengthened due to reduced mixing; and 3) the pressure field of downstream turbines can move and modify wakes flowing close to them.