Recent advances in modeling of wind turbine wake vortical structure using a differential actuator disk theory

Abstract

This paper presents the recent developments of a new CFD-based method aimed at predicting wind turbine aerodynamics, where velocity and pressure discontinuities are used to model the vortical system that creates lift on the turbine blades. To illustrate the ability of the present model to predict induced wake effect, the case of the taper wing is thoroughly analyzed and effects of both domain discretization and convection scheme are presented. Results are mitigated regarding predicted performance of induced drag, but accurate induced and upstream flow angles values are obtained. The method is even shown to be a useful calculator for the relationship between inflow angle measured upstream and effective angle of attack of a wing section. Interesting results for the NREL phase VI rotor have been obtained showing improvement of the method upon actuator-disk approach in handling tip vortices effect on the blade aerodynamics.