Prediction of Resonance Frequencies for Ventilated Wall Wind Tunnels,

Abstract

Based on the reflection and refraction of plane acoustic waves at an interface between the moving stream and the stagnant plenum air, a simple theory is developed for ventilated walls. The intensity and frequency of resonance are determined from the modulus and the argument of the wall reflection coefficient respectively. In contrast to the eigenvalue method, the present technique is capable of predicting partial resonance, occuring in perforated walls and also in slotted walls at Mach numbers below 0.618, for which the resonant waves are partly reflected and partly transmitted at the wall. The reverse transmission of waves from the plenum into the test section is found to be inconsistent with the postulated resonance condition and is therefore not considered.

Document Details

Document Type
Technical Report
Publication Date
Feb 01, 1984
Accession Number
ADP003768

Entities

People

  • M. Mokry

Organizations

  • National Research Council Canada

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Acoustic Waves
  • Coefficients
  • Contrast
  • Eigenvalues
  • Frequency
  • Frequency Shift
  • Intensity
  • Mach Number
  • Reflection
  • Refraction
  • Resonance
  • Waves
  • Wind Tunnels

Fields of Study

  • Physics

Readers

  • Combustion and Flow Dynamics.
  • Optical Physics and Photonics.
  • Structural Dynamics.