Accession Number : ADA325438

Title :   Diffraction of Sound by Objects in the One-Wavelength Size Range.

Descriptive Note : Technical manuscript,

Corporate Author : ARMY CENTER FOR HEALTH PROMOTION AND PREVENTIVE MEDICINE ABERDEEN PROVING GRO UND MD ENVIRONMENTAL HEALTH ENGINE

Personal Author(s) : Lee, Soon Y.

PDF Url : ADA325438

Report Date : MAY 1997

Pagination or Media Count : 66

Abstract : The diffraction of sound by hard geometrical shapes has been studied by the Method of Moments (MOM), a boundary element technique for solving the scalar Helmholtz integral equation. The scattered fields of several rectilinear shaped objects are analyzed. The problem of scattering by an axially-symmetric obstacle has been simplified by using the symmetry to reduce the computational load. The validity of the resulting procedure has been verified by comparing the MoM results for a flat circular disk illuminated by either a plane or spherical wave with the results obtained by the classical method of separation of variables and expansion in oblate spheroidal wave functions.

Descriptors :   *WAVE FUNCTIONS, *ACOUSTIC SCATTERING, *METHOD OF MOMENTS, *ACOUSTIC REFLECTION, COMPUTATIONS, GEOMETRIC FORMS, BOUNDARY VALUE PROBLEMS, SCALAR FUNCTIONS, INTEGRAL EQUATIONS, HELMHOLTZ EQUATIONS.

Subject Categories : Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE