Quarterly Progress Report for April, May, and June 1970

Abstract

In Section 1 it is shown by using the simplest reflecting surface--an infinite, pressure release plane surface--that at least the Fresnel phase approximation and a reasonable directivity pattern approximation are necessary before accurate predictions in surface reflection and scattering problems can be made. The average Rayleigh reflection coefficient for random penetrable surfaces of various roughnesses is calculated in Section 2. In Section 3 an integral expression is derived for the acoustic field of a point source in a surface duct with a rough boundary. The integral was obtained by Green's functions and includes the rough surface condition by means of an effective impedance condition which also depends on the properties of the medium.

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Document Details

Document Type
Technical Report
Publication Date
Jul 21, 1970
Accession Number
ADA037370

Entities

Organizations

  • University of Texas at Austin

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Acoustic Fields
  • Acoustic Phenomena
  • Acoustic Propagation
  • Acoustic Waves
  • Acoustics
  • Boundaries
  • Contracts
  • Equations
  • Frequency
  • Geometry
  • Integrals
  • Random Variables
  • Reflection
  • Roughness
  • Surface Properties
  • Three Dimensional
  • Waves

Fields of Study

  • Physics

Readers

  • Electromagnetic Wave Scattering and Antenna Radiation Engineering