ヘルムホルツ共鳴器アレイを用いた開放型消音器によるブロワ騒音の低減

抄録

This study proposes an open silencer utilizing a Helmholtz resonator (HR) array to reduce blower noise. Most blowers generate uncomfortable high-frequency noise due to their high-speed rotating parts. However, the conventional passive noise control (PNC) method using a physical sound insulator reduces their airflow. The proposed HR array plate consists of HR elements and penetration hole elements densely arrayed like a honeycomb structure. Multiple HR elements arranged around the penetration hole effectively attenuate the noise in the resonant frequency. Due to the high aperture ratio, the HR array plate insulates a noise without blocking airflow. The prototype device realized a 10 dB reduction in 2 ~ 4 kHz, where the noise spectrum of a typical blower has a peak.