Aeroacoustics of Air Purifier Centrifugal Fan Design

Ian Yin Wai Wong, Chi Kin Randolph Leung, Anthony Kwok Yung Law

Research output: Chapter in book / Conference proceedingConference article published in proceeding or bookAcademic researchpeer-review

Abstract

The sound generation mechanism of an existing air purifier centrifugal fan is firstly investigated by three dimensional numerical flow calculations. The simulation is carried with the Large Eddies Simulation (LES) approach to account the turbulent effect of the flow. The sound pressure level of the fan at the observer location is predicted separately by; 1. the Ffowcs Williams and Hawkings (FW-H) formulation (solution obtained free space Green's function) alone and; 2. the formulation with inclusion of reflection and scattering effects of fan housing (regarded as complete way of noise estimation with correction of scattering and reflection by boundary element method). Both calculations acquire the unsteady aerodynamic forces acting onto the fluid by the rotating blades obtained from the flow calculations as the source term. In the first part, the unsteady noise source is identified. The flow interaction with the volute tongue is the dominant noise source as identified from the flow field results. In the aeroacoustic calculation, it is found that the noise level calculated by FW-H equation is over-predicted; the difference from the measured value at BPF is about 3 dB. There are also some deviations from the first harmonic of the BPF. On the contrary, when the effect of scattering and reflection are taken into account, the noise level is better predicted. The difference from measurement at BPF narrowed to about 1 dB and the SPL spectrum agrees well with measurement.
Original languageEnglish
Title of host publicationINTER-NOISE 2017 - 46th International Congress and Exposition on Noise Control Engineering: Taming Noise and Moving Quiet
PublisherInstitute of Noise Control Engineering
Publication statusPublished - 1 Jan 2017
Event46th International Congress and Exposition on Noise Control Engineering: Taming Noise and Moving Quiet, INTER-NOISE 2017 - Hong Kong Convention and Exhibition Centre (HKCEC), Hong Kong, Hong Kong
Duration: 27 Aug 201730 Aug 2017

Conference

Conference46th International Congress and Exposition on Noise Control Engineering: Taming Noise and Moving Quiet, INTER-NOISE 2017
Country/TerritoryHong Kong
CityHong Kong
Period27/08/1730/08/17

Keywords

  • Fan noise
  • LES
  • Scattering effects

ASJC Scopus subject areas

  • Mechanical Engineering
  • Acoustics and Ultrasonics

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