Abstract:

Wind induced noise is a problem that affects most outdoors acoustic measurement campaigns. The interaction between the local wind and turbulence with the fixed surfaces of the microphone generates non-acoustic pressure fluctuations at the diaphragm that significantly affect the microphone output. Various types of wind shields are used to overcome this problem, but the benefit of this measure is generally not well quantified. This issue is particularly relevant in the context wind farm assessments, where the dependency of ambient noise as a function of the local wind speed is of primary importance when determining the noise criteria and undertaking the compliance noise measurements at the site. This paper presents the results of wind generated noise testing for a range of commercially available wind shields. It is demonstrated that the principal variable in wind screen performance is the diameter of the wind-screen.