A Generic Silent Blower Module Based on a Dual Active Noise Control System

摘要

Active noise control (ANC) is a well known technique to reduce noise of air-moving devices, such as fans and blowers. While axial fans equipped with ANC systems demonstrate significant noise reduction even within rather small dimensions, applying ANC systems to blowers appears to be more challenging. Part of the challenge stems from the complexity of the airflow pattern compared with the airflow of axial fans. While the airflow in the inlet of the blower is rather homogeneous and laminar, the airflow in the outlet is turbulent which can decrease ANC performance. This work aims at developing a method to overcome the airflow complexity challenge for applying ANC systems to both sides of a blower, in order to attain a generic silent blower. The confirmation for the effectiveness of the method is the active sound power level (SWL) reduction of 7.8 dB (A) on top of the passive reduction that was demonstrated. A significant potential was identified for producing a generic silenced blower module with the required airflow, but with a lower level of noise.