Noise Suppression in Jet Inlets.

Abstract

This research program was concerned with the development of an analytical technique, based on an integral representation of the external solutions of the Helmholtz equation, for the prediction of the sound radiated from complicated, acoustically lined, axisymmetric bodies having complex sound sources. The purpose of this research program was to generate efficient computer codes for the prediction of the sound radiated from acoustically lined jet engine inlets. In the experimental tests two geometrical configurations were studied, a straight duct and a jet engine inlet. Both of these configurations were tested with hard walls and the straight duct was tested with an acoustic liner consisting of a matrix of Helmholtz resonators. It was found that very good agreement was obtained for the hard walled configurations while there were some discrepancies with the lined wall case. It is conjectured that this discrepancy in some of the lined wall results is mainly due to the particular liner theory used to calculate the effective admittance of the liner.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Feb 01, 1980
Accession Number
ADA085403

Entities

People

  • Ben T. Zinn
  • Brady R. Daniel
  • William L. Meyer

Organizations

  • Georgia Tech

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Accuracy
  • Acoustic Absorption
  • Acoustic Admittance
  • Acoustic Impedance
  • Acoustic Measurement
  • Acoustic Phenomena
  • Acoustic Propagation
  • Acoustic Reactance
  • Acoustic Velocity
  • Acoustics
  • Anechoic Chambers
  • Computer Programs
  • Electronic Equipment
  • Engineering
  • Integral Equations
  • Measurement
  • Resonant Frequency

Fields of Study

  • Physics

Readers

  • Aerospace Engineering
  • Electromagnetic Wave Scattering and Antenna Radiation Engineering
  • Fluid Mechanics and Fluid Dynamics.