Validation of a wake model for vertical-axis wind turbine farms

Abstract

An analytical wake model can be used to predict the power generated by a vertical-axis wind turbine farm. The accuracy of a specific wake model is investigated in this study. In particular, the velocity field within the farm is analyzed since it determines the power that can be generated by each turbine. On a two-turbine layout, the velocity field obtained with the wake model is compared to that given by a computational fluid dynamics (CFD) simulation. The two-dimensional CFD simulation is performed with an actuator line model of the turbine blades and Reynolds-averaged Navier-Stokes turbulence modeling. One of the major findings is that the wake model results are highly dependent on the choice of combination model used to superpose wakes of multiple turbines. The results also show that one of the combination models has a better agreement with the CFD simulation. However, this comparison is limited by the accuracy of the turbulence modeling within the CFD simulation. Despite this limitation, this study is a step towards accurately modeling a vertical-axis wind farm.