DC FAN NOISE EMISSION CHARACTERIZATION FOR ITTE INDUSTRY

摘要

This paper discusses a half-scaled fan plenum and its application in understanding fan soundpressure fields, estimating fan sound power levels, and balancing thermal with acoustics insystem design. The fan plenum as a key apparatus in characterizing fan noise emission needs tobe qualified properly to enable accurate assessment of the fan’s performance. The insertion lossmeasurement requires a measurement setup with more spatial samplings than ISO 7779[3] hasprescribed. It is recommended to revise ISO 10302[1] to prescribe a methodology with morespatial samplings that the basic requirement of ISO 7779[3].Fan sound field visualization is a good tool to understand fan acoustics, to facilitate fanacoustic design and to validate fan design concepts. This paper concludes that fan sound fieldsdo not resemble a monopole, nor a perfect dipole, and estimation of sound power levels using themonopole assumption leads to a 4-6 dBA error. Fan sound power level vs. air pressure curveprovides a way for design engineers to take both thermal and acoustics into account whenselecting a fan for electronic cooling.