Accession Number:

ADA155476

Title:

Acoustic Radiation from Concentric Shells Containing an Inner Fluid

Descriptive Note:

Technical rept.

Corporate Author:

WEIDLINGER ASSOCIATES NEW YORK

Personal Author(s):

Report Date:

1985-01-01

Pagination or Media Count:

69.0

Abstract:

The acoustic radiation characteristics of a fluid filled concentric shell structure are investigated by making use of the simple source surface integral method. The fluid field is described in terms of surface expansion functions, while the in vacuo structural modes, obtained by using the BOSOR4 structural program, are used as a basis for the shell motions. The structural code can be applied to branched shells of revolution, thereby obviating the need to introduce structural coupling of the two shells in a manner which is external to the main code. For illustrative purposes three types of internal harmonic excitations have been considered 1 an axisymmetric unit pressure acting on the central region, 2 a unit line load acting on the central region, and 3 concentrated axial loads acting at the poles of the spherical closures. The far field fluid pressures have been obtained for a wide range of frequencies for both the single shell and for the double shell with and without inner fluid. Because of numerical difficulties encountered when applying the integral methods to internal fluid problems, some simple approximations to the internal fluid problem were considered. The results obtained compare quite favorably with those of the exact solution over a wide range of frequencies.

Subject Categories:

  • Acoustics
  • Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE