Active control of centrifugal fan noise: Modeling design guidelines

• Published in: The Journal of the Acoustical Society of America 2011-04, Vol.129 (4_Supplement), p.2584-2584
• Main Authors: Esplin, J. James, Boyle, John K., Sommerfeldt, Scott D., Gee, Kent L.
• Format: Article
• Language: English
• ISSN: 0001-4966; 1520-8524
• DOI: 10.1121/1.3588542

Information technology (IT) noise is very prevalent in today’s society. Active noise control (ANC) has shown promise in minimizing the effect of fan-induced IT noise on users. Much of the previous research has concentrated on axial cooling fans, such as those found in desktops and servers. This approach was based on the concept of minimizing radiated acoustic power in a model of the fan radiation, and using those results to determine appropriate nearfield locations for the error sensor(s). This paper describes modifications to this previous method to develop a modeling approach to implement active noise control with a centrifugal blower, such as those found in fan trays and laptop computers. This model has been used to predict tonal noise inside and outside the duct, as well as how to best develop an ANC system for such an idealized setup. Differences between the axial fan model and the centrifugal blower model are discussed, as well as some limiting assumptions for each model.