Dynamic flow analysis using an OpenFOAM based CFD tool: Validation of Turbulence Intensity in a testing site

¹ Suzlon Energy A/S, Wind and Site Competence Centre, Bredskifte Allé 13, 8210 Aarhus, Denmark
² IB Fischer CFD+engineering GmbH, Lipowskystraße 12, 81373 München, Germany

^a e-mail: livio.casella@suzlon.com

Abstract

The presenting paper investigates on the validation of the turbulence intensity (TI) modeled by a CFD tool. Six meteorological masts, equipped with cup anemometers, have been used for the purpose. Three different turbulence closure schemes, which are the SST k-omega and the k-epsilon in two different configurations, have been tested. The flow analysis shows a qualitative agreement between measurements and models, which are capable to simulate the turning of the wind towards South when it comes from SSE. Furthermore, the simulations predict a zone of high turbulence in the northern part of the site that is confirmed by the local measurements. The scores for TI have been quantified by considering the observed directional frequencies in the validation analysis. For the testing site, the SST k-omega scheme achieves the best performance when using the TI definition which is representative of the longitudinal fluctuations of the velocity vector, against the other one, which considers the fluctuation of the horizontal vector. Lastly, the model errors have been used to correct the simulated values using two approaches; the analysis shows that, for the presented case, these correction methods do not always improve the accuracy of the simulations.