A wake vortex model for horizontal-axis wind turbine and its calculation method

Based on the existing wake vortex model,a new method was put forward to calculate the wake.The wake was divided into a near vortex zone and a far one in this new wake model.In the former,the wake vortex could be obtained analytically in a selected fan-shaped cross-section while in the latter the wake vortex would be determined by nonlinear interpolation.Selecting limited discrete points in the wake,the induced velocity would be calculated and the wake expanding radius determined on the basis of continuity equations of fluid flow,so that the divergence of the tip vortex radius was avoided and the amount of computation was reduced greatly.Through a typical example of wind turbine,the distribution pattern of axial induction factor computed by this method was more reasonable compared with the result obtained by the rigid wake model.This verified the correctness and practicability of this method which could provide an effective wake vortex calculation method for the aerodynamic design and performance calculation of horizontal-axis wind turbine rotors.