Performance and wake development behind two in-line and offset model wind turbines - 'Blind test' experiments and calculations

摘要

This is a report on data presented at the ”Blind test 3” Workshop organizedjointly by Nowitech and Norcowe in Bergen, December 2013. A number of researchgroups were invited to predict the performances and the wake development behindtwo model wind turbines that have been extensively tested at the Department ofEnergy and Process Engineering, NTNU. The turbines were arranged in-line, butslightly offset so that the wake of the upstream turbine only affected roughly half thearea swept by the second rotor. This is a common event in most wind parks andproduces flow fields that are both complicated and harmful for the downstreamturbine. Contributions were received from five different groups using a range ofmethods, from fully resolved Reynolds averaged Computational Fluid Dynamics(CFD) models to Large Eddy Simulations (LES). The range of results was large butthe overall trend is that the current methods predict the power generation as well as thethrust force reasonably well. But there is a large uncertainty in the prediction of theturbulence field in the wake.