Active noise control for centrifugal and axial fans

Fans are widely used in industry for heat dissipation or airflow production. It is achieved by driving a motor of fan to rotate a number of blades. Most industrial fans can be categorized into one of two general types: centrifugal fans and axial fans. However, fan noise is loud when the motor speed is high. This article develops using active noise control (ANC) system to reduce noise from both centrifugal and axial fans. By integrating loudspeakers and microphones, we present multiple-channel feedback ANC structure with the filtered-X least mean square (FXLMS) algorithm to simultaneously reduce noise from the inlet and the outlet of the fans. Several realtime experiments verify that the proposed method and experimental setup not only reduces the narrowband noise but also achieves the global cancellation of the fan noise.