The Propagation of a Spherical N Wave in an Absorbing Medium and Its Diffraction by a Circular Aperture.

Abstract

The report investigates the effects of finite amplitude on the diffraction of a spherical N wave by a circular aperture. The investigation was to be carried out in the farfield of the aperture, i.e., where the incident and diffracted signals were not completely resolved. An experiment was done in which an N wave was produced by an electric spark. A condenser microphone received the acoustic signal, and an aperture in a rigid baffle was placed between the spark and the microphone. The preliminary investigations revealed that, in the farfield, absorptions as well as nonlinear distortion is important. A computer algorithm was developed in which the effects of nonlinear distortion and absorption are combined in a stepwise manner. To test the algorithm, it was used to predict the waveform of a propagating N wave. The predicted waveforms agree very favorably with experiment. (Modified author abstract)

Document Details

Document Type
Technical Report
Publication Date
Aug 01, 1974
Accession Number
AD0787878

Entities

People

  • Mark O. Anderson

Organizations

  • University of Texas at Austin

Tags

DTIC Thesaurus Topics

  • Absorption
  • Abstracts
  • Acoustic Signals
  • Algorithms
  • Amplitude
  • Computers
  • Diffraction
  • Distortion
  • Microphones
  • Waveforms
  • Waves

Fields of Study

  • Physics

Readers

  • Acoustical Oceanography.
  • Acoustics.
  • Structural Dynamics.