A Secondary Source Configuration for Control of a Ventilation Fan Noise in Ducts

作者：Prezelj Jurij^*; Cudina Mirko

来源：Strojniski Vestnik-Journal of Mechanical Engineering, 2011, 57(6): 468-476.

DOI：10.5545/sv-jme.2009.026

• active noise control
• secondary source
• ventilation duct
• noise
• fan

The main noise source in heating, ventilation, and air conditioning systems is usually a ventilating fan. Noise, generated by the ventilating fan is transmitted through the duct into the living and working environment. A typical fan noise spectrum consists of a broadband noise, which is superimposed with pure tones. Different methods are available to reduce a transmission of such noise from the ventilating fan into the living and working environment. In this article it is demonstrated how a feedforward active noise control system can be implemented together with a side branch resonator Effectiveness of the feedforward active noise control system depends on the quality of a reference signal, which should be in a perfect correlation with the primary noise. An acoustic feedback is the main problem of feedforward active noise control systems in ducts. A combined method uses a single loudspeaker to work as a dipole source and a side branch resonator to reduce the acoustic feedback. A side branch resonator reduces noise transmission in a narrowband frequency range as well. In this article, a theoretical background of a dipole source with a side branch resonator is presented, along with some measurement results and simulations of active noise control.

• 出版日期2011-6