An Initial Study on Applying Active Noise Control to an Insulated Box Fan Used in Ventilation System Applications
Blekinge Institute of Technology, School of Engineering, Department of Signal Processing2009 (English)Conference paper (Refereed) Published
In many different applications and buildings fans are used to remove unwanted and used air. These fans often generate broadband and tonal noise. Commonly, passive resistive silencers are used to attenuate noise generated by different types of fans installed in ventilation systems. Passive silencers tend to become bulky and impractical when designed for low frequency attenuation. However, active noise control (ANC) is a technique known for its ability to produce high levels of attenuation in the low frequency range, even with a relatively moderate sized ANC system. This paper presents an initial study performed to investigate the possibilities of applying ANC to a radial fan installed inside a box, an insulated box fan. The box is connected to a duct system and can for example be used as a waste air fan. The primary interest in this application, when the fan is used as a waste air fan, is to attenuate the noise generated on the suction side, since that side generates noise into a particular room. Investigations were carried out to determine where the ANC system should be installed, e.g. inside the box, in the duct connected to the box etc. Factors considered were for example, turbulence, standing waves, the type of noise generated by the fan (tonal, broadband, or a combination), and space limitations. The noise generated by the fan was found to be dominated by a tonal component, but also to have broadband energy in the low frequency range. Further, a feedforward ANC system was applied on the suction side, producing approximately 28 dB attenuation of the tonal component, and 5-10 dB attenuation of the broadband noise between 50 and 200 Hz.
Place, publisher, year, edition, pages
Fan noise, adaptive signal processing, ANC, turbulence, active noise control, measurement noise
IdentifiersURN: urn:nbn:se:bth-8041Local ID: oai:bth.se:forskinfoD495FAB8977132EDC12575ED0036B7BDOAI: oai:DiVA.org:bth-8041DiVA: diva2:835725
The Sixteenth International Conference on Sound and Vibration, ICSV 16