同相回転音源に対する騒音低減手法の提案

抄録

In this paper, we propose the active noise control method for the rotation sound sources. In case the rotation sound sources has zero lob mode, this lob mode is radiate from the duct fan without attenuation in the duct. Therefore, noise control is need for the rotation sound sources has zero lob mode. From the view of active noise control (ANC), we can treat this zero lob mode as the plane wave radiation from the duct. Therefore, we propose the ANC method with the two control speakers set outside of the duct. The point of this method to attenuate zero lob mode are the small number of the control speakers and control speakers are set outside of the duct. Moreover, we verify this method with the simulation and experiment. In the experiment of duct fan with two blade, the noise attenuation level around the duct was from 8 dB to 12 dB.