Discrete Frequency Noise and Its Reduction in Small Axial-Flow Fans.

Abstract

The discrete frequency noise radiated from representative types of axial-flow fans used in electronic equipment is studied in detail. Narrowband analysis of the discrete frequency noise radiated by these types of fans has been conducted in a free-field environment. The far-field sound pressure level, radiated directivity, and total radiated power of the discrete frequency noise is presented. The influence of operating point on the sound radiated from the fans is determined. The discrete frequency noise dominates the characteristic acoustic spectra at high flow coefficients. (Author)

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Document Details

Document Type
Technical Report
Publication Date
Mar 02, 1982
Accession Number
ADA118439

Entities

People

  • James Michael Fitzgerald

Organizations

  • Pennsylvania State University

Tags

Communities of Interest

  • Energy and Power Technologies
  • Ground and Sea Platforms

DTIC Thesaurus Topics

  • Acoustic Absorption
  • Acoustic Measurement
  • Acoustic Propagation
  • Acoustic Waves
  • Acoustics
  • Aerodynamic Characteristics
  • Anechoic Chambers
  • Axial Flow
  • Boundary Layer
  • Electronic Equipment
  • Pressure Distribution
  • Sound Pressure
  • Standing Waves
  • Static Pressure
  • Test And Evaluation
  • Test Equipment
  • Test Facilities

Fields of Study

  • Physics

Readers

  • Acoustics.
  • Aerodynamics.

Technology Areas

  • Microelectronics