Measuring noise in high wind speeds: Evaluating the performance of wind shields

The issue of correctly assessing and monitoring wind farm noise is growing in importance as the number of wind farms in operation continues to rise, in an effort to increase the production of green energy. Consequently the issue of correctly monitoring and predicting wind noise has become an issue of more importance in Ireland. According to best practice guidelines this involves noise measurements at wind speeds up to 12m/s. However, international standards generally state that microphone wind shields are only effective up to 5m/s whereas most wind turbines are operative for wind speeds between 4m/s and 20m/s. A reliable method to measure noise in high speed winds is therefore required. This paper describes an initial step towards this goal. The effect of using a windshield on a microphone was established in both flow and no flow environments. In the instances where hydrodynamic noise was an issue (i.e. a "windy" environment) the effect of exceeding the 5m/s limit was analysed. It is proposed that this work could contribute to the development of correction factors associated with wind speeds and these correction factors could then be applied to field measurements.