Abstract
Horizontal axis wind turbine (HAWT) with downwind rotor location is well known to generate an impulsive low-frequency noise. Large-scale downwind machines caused several low-frequency noise problems in overseas countries. This paper describes firstly measured results of the noise generated by a 15m diameter HAWT “WINDMEL.” Generation of an impulsive low-frequency noise by the downwind WINDMEL has been ascertained in the current measurement, though it was of a rather low level. In case of the upwind WINDMEL, generation of this noise could not be ascertained. Next, the predictive calculation of an impulsive low-frequency noise is carried out based on an available method. Namely, assumptions and cautions required for the predic tivecalculation are presented and discussed. Furthermore, applicability of the cal culationmethod is discussed based on the comparisons between the calculated results and the measured data.
