Experimental and Analytical Study of the Hydroacoustics of Propellers in Rigid Ducts

Abstract

This report describes the results of a detailed study of the fluid dynamics and acoustic signature of a rotor operating in a rigid duct. The study focused on the separation of the acoustic source functions and the system response, or transfer function. A new algorithm was developed and quantified to separate these functions from radiated sound measurements. Measurements of the approach flow turbulence and propeller wake turbulence provided insight into the nature of the acoustics sources. It was found that approach flow noise is only responsible for the sound produced at frequencies less than the first blade rate tone. Higher frequencies were dominated by complex rotor self noise that included broad humps in the source spectra at integer multiples of the blade passing frequency.

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Document Details

Document Type
Technical Report
Publication Date
Jul 01, 2006
Accession Number
ADA451574

Entities

People

  • Scott C. Morris
  • Thomas Mueller

Organizations

  • University of Notre Dame

Tags

Communities of Interest

  • Air Platforms
  • Ground and Sea Platforms

DTIC Thesaurus Topics

  • Acoustic Measurement
  • Acoustic Phenomena
  • Acoustic Propagation
  • Acoustic Properties
  • Acoustic Waves
  • Acoustics
  • Boundary Layer
  • Computational Fluid Dynamics
  • Computational Science
  • Doppler Effect
  • Fluid Dynamics
  • Fluid Flow
  • Fluid Mechanics
  • Hydrodynamics
  • Measurement
  • Propulsion Systems
  • Standing Waves

Fields of Study

  • Physics

Readers

  • Acoustical Oceanography.
  • Aerodynamics.
  • Fluid Mechanics and Fluid Dynamics.