Duct Liner Optimization for Turbomachinery Noise Sources

Abstract

An acoustical field theory for axisymmetric, multisectioned lined ducts with uniform flow profiles is combined with a numerical minimization algorithm to predict optimal liner configurations having one, two, and three sections. Source models studied include a point source located on the axis of the duct and rotor/outlet-stator viscous wake interaction effects for a typical research compressor operating at an axial flow Mach number of about 0.4. For this latter source, optimal liners for equipartition-of-energy, zero-phase, and least-attenuated-mode source variations are also calculated and compared with exact results. It is found that the potential benefits of liner segmentation for the attenuation of turbomachinery noise is greater than would be predicted from point source results. Furthermore, effective liner design requires precise knowledge of the circumferential and radial modal distributions. Duct acoustics, Aircraft noise, Turbomachinery noise.

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Document Details

Document Type
Technical Report
Publication Date
Nov 01, 1975
Accession Number
ADA279441

Entities

People

  • Harold C. Lester
  • Joe W. Posey

Organizations

  • National Aeronautics and Space Administration

Tags

Communities of Interest

  • Advanced Electronics
  • Air Platforms

DTIC Thesaurus Topics

  • Acoustic Absorption
  • Acoustics
  • Algorithms
  • Attenuation
  • Axial Flow
  • Computer Programs
  • Frequency
  • Impedance
  • Intermediate Frequencies
  • Losses
  • Mach Number
  • Noise
  • Plane Waves
  • Spatial Distribution
  • Transmission Loss
  • Two Dimensional
  • Waves

Fields of Study

  • Physics

Readers

  • Acoustics.
  • Adaptive Control and Estimation with Uncertainty in Dynamic Systems.
  • Aerodynamics.