Acoustic Radiation Fields of Axisymmetric Spherical Sources with Mixed Boundary Conditions.

Abstract

Three acoustic radiation problems concerning axisymmetric radiating spheres with mixed boundary conditions on their surfaces have been treated numerically. They are: first, a radially vibrating polar cap mounted on an otherwise rigid spherical baffle; second, the same cap mounted on an otherwise pressure release spherical baffle; and third, the same cap and a contiguous pressure release belt, both mounted on an otherwise rigid spherical baffle. The solution of the first problem is obtainable in terms of eigenfunctions which are orthogonal over the sphere and is consequently well known; it was thus used as a comparison check for the second and third problem. The solutions of the above problems were accomplished by assuming a Fourier-Legendre series expansion of the acoustic pressure field and numerically determining the coefficients in the expansion, either by the least mean square error method, or by boundary collocation. The first and second problems were solved by both methods, while the third was treated by the least mean square error method only. The numerical computations were performed on an IBM 370/168 digital computer in FORTRAN IV.

Document Details

Document Type
Technical Report
Publication Date
Mar 11, 1976
Accession Number
ADA027522

Entities

People

  • Christopher C. Gerding

Organizations

  • Pennsylvania State University

Tags

DTIC Thesaurus Topics

  • Axisymmetric
  • Boundaries
  • Coefficients
  • Computations
  • Computers
  • Computing Devices
  • Digital Computers
  • Eigenvectors
  • Mathematical Analysis
  • Mathematics
  • Polar Cap
  • Radiation

Readers

  • Approximation Theory.
  • Electrical Engineering
  • Fluid Dynamics.