INVESTIGATION OF METHODS FOR THE PREDICTION AND ALLEVIATION OF LIFT FAN NOISE

Abstract

A research investigation into the generation, suppression and prediction of fan noise was completed. The theoretical investigations provided insight into the basic noise generating mechanism of fan noise commonly called fan or compressor 'whine'. Acoustic normalizing techniques resulted in a correlation curve of the overall sound power for 13 separate fan and compressor vehicles with each one being from a different design family. Investigation of noise minimization through design techniques incorporated the results of the analytical investigations and the normalized sound power relations. Results indicate the effect or rotor-stator spacing, blade number, RPM, inlet length and centerbody design. Suppression techniques evaluated were wave cancellation, deflection, and absorptive suppressor designs. Test results of an absorptive type suppressor show up to 10.5 db maximum suppression as tested with a sale model fan configuration.

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Document Details

Document Type
Technical Report
Publication Date
Apr 01, 1965
Accession Number
AD0616267

Entities

People

  • Harry D. Sowers

Organizations

  • General Electric

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Acoustic Propagation
  • Acoustic Waves
  • Acoustics
  • Aircrafts
  • Computer Programs
  • Computers
  • Data Acquisition
  • Guide Vanes
  • Inlet Guide Vanes
  • Jet Engines
  • Measurement
  • Recording Systems
  • Research Aircraft
  • Sound Waves
  • Standards
  • Test And Evaluation
  • Test Facilities

Fields of Study

  • Engineering
  • Physics

Readers

  • Acoustics.
  • Aerodynamics.
  • Systems Analysis and Design

Technology Areas

  • Space