Acoustic noise emission from 15m diameter horizontal axis wind turbine generator with downwind configuration

Abstract

Measurements on acoustic noise emission from the downwind 15m diameter horizontal axis wind turbine generator (installed at Mechanical Engineering Laboratory under MITI's Sunshine project) have been carried out for the purpose to obtain basic data necessary for a future noise reduction and assessment study. In this paper, characteristicsof aerodynamic and mechanical noise of the machine in an audible frequency range are presented and a mechanism of noise sources is discussed. Further, the reference sound level and the directivity index are determined according fundamentally to the IEA Recommended Practice on acoustic noise measurements. Also the dependence of noise on wind speed and operating conditions is presented.