This article studies the effects of some basic parameters of a parallel-axis helix gear stage on wind turbine gearbox vibration in a case study: a multibody dynamic model is constructed to simulate the drive train of a faulted multistage wind turbine gearbox with serious vibrations. The significant vibration behaviour of the drive train for typical excitations is calculated, and the results according to specified geometric parameters of the gears are analysed in detail to investigate effective solutions for vibration reduction. The results indicate that the helix angle and numbers of teeth of a gear pair are the most significant factors for solving the problem. The effectiveness of the proposed solutions and relevant mechanisms are discussed and validated by a prototype vibration test.

This paper proposes a method of controlling the vortex-induced vibration (VIV) of wind turbine towers by adding continuous trapezoidal straight spoiler plates (TS) onto their outer surface: a fluid–solid coupling model was constructed to simulate the processes of Karman vortex generation and shedding on the different surfaces of an original tower (O–tower) and a tower with TS (TS–tower) with assumed and actual Re, while the VIV frequencies were also calculated and compared; the effects of the TS geometry parameters on the VIV frequency of towers were studied to investigate the recommended size; a modal analysis was carried out to research the effects of TS on the vortex-induced resonance risk of towers; and the simulation results as well as relevant research conclusions were validated by an analogical wind tunnel test.