Noise Suppression in Jet Inlets.

Abstract

This report summarizes the work performed during the first year of a research effort to determine the sound fields associated with jet engine inlet configurations. A solution approach for axisymmetric bodies based upon the integral formulation of the wave equation has been developed. This solution approach circumvents the uniqueness problems which normally occur at certain frequencies when 'straight forward' solutions of the integral equation are obtained. A numerical method and a computer program for solving for the acoustic field associated with general inlet configurations and boundary conditions have also been developed. To evaluate the numerical method, computed and exact results are compared for a sphere and a finite length cylinder. For continuous boundary conditions, the agreement is within ten per cent over a range of nondimensional frequencies from one to ten. For discontinuous boundary conditions, the numerical errors increased by a factor of two. This report presents results for a given inlet configuration and the computed and exact solutions are shown to agree to within ten per cent over the nondimensional frequency range from one to ten. (Author)

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Document Details

Document Type
Technical Report
Publication Date
Feb 01, 1978
Accession Number
ADA054173

Entities

People

  • Ben Zinn
  • William A. Bell
  • William L. Meyer

Organizations

  • Georgia Tech

Tags

Communities of Interest

  • Air Platforms
  • Ground and Sea Platforms
  • Weapons Technologies

DTIC Thesaurus Topics

  • Acoustic Properties
  • Acoustic Velocity
  • Acoustics
  • Computational Fluid Dynamics
  • Computational Science
  • Computer Programs
  • Differential Equations
  • Equations
  • Frequency
  • Gaussian Quadrature
  • Geometry
  • Helmholtz Equations
  • Integral Equations
  • Numerical Analysis
  • Plastic Explosives
  • Resonant Frequency
  • Wave Equations

Readers

  • Aerospace Engineering
  • Calculus or Mathematical Analysis
  • Fluid Dynamics.