Potential noise reduction from mast trailing vanes as downwind-Design wind turbine retrofits

摘要

Older wind turbine generators (WTG) featuring rotors that are “downwind” of the nacelleand its supporting mast structure have the reputation of being noisier than their “upwind”design counterparts on the argument that the aerodynamic wake from the mast introducesnoise-producing turbulence at the interaction area of the passing rotor blades. Possiblemethods of improving the wake, for the purpose of reducing this blade-interactionturbulence and hence noise production, could include the addition of a flat plate or similarstructure or device to the trailing side of a mast structural element. Realization of such aconceptual device would likely be a retrofit to a pre-existing downwind-design WTG-ifmast-to-rotor clearance and other practical parameters allow. This study attempts toquantify the noise reduction potential of such retrofit or new mast design concepts,focusing attention on turbulence intensity and its relationship to aerodynamic drag.