Influence of Model Parameters in the Analytical Wake Profile of a Wind Turbine on Wind Farm Design
This research paper compares the predicting capabilities of four different analytical wake models, namely Jensen, Frandsen, Larsen and Ishihara used in wind farm design. Generally, these models consist of few parameters to be adjusted for better prediction. The available wind turbine experimental data was considered for the accuracy of prediction. Among the four models, the velocity profile predicted from the Larsen model shows reasonably good agreement with the experiments. The Jensen and Frandsen model assume top-hat profile for wake velocity. The Larsen and Ishihara models allows variation of velocity in radial direction. Since the wake velocity affects the power production in the downstream turbine, the four models were compared for power production from a second turbine placed at downstream axial location. A maximum of about 18 % deviation in power production was noticed. Though the thrust coefficient (CT) is a turbine parameter and it vary with inflow velocity, a parametric study on CT describes that the power prediction from various models differs significantly with varying CT. Parametric study on wake decay coefficient and ambient turbulence were carried out to identify it’s influence on velocity profile. As the models predicts difference in power, a comprehensive study of various models on prediction of wind farm power production is necessary to understand the overall characteristics of wind farm before performing high-fidelity simulations.