Accession Number : AD0477005

Title :   UNDERWATER SOUND RADIATION FROM A FINITE CYLINDER: GENERAL ANALYSIS,

Corporate Author : BOLT BERANEK AND NEWMAN INC CAMBRIDGE MA

Personal Author(s) : Smith, P. W., Jr. ; Kerwin, E. M., Jr.

Report Date : 15 MAR 1965

Pagination or Media Count : 51

Abstract : The sound radiation from vibrations of a finite, air-filled, thin cylindrical shell is studied by a multi-modal approach. The modes are classified according to their resonance characteristics and their efficiencies of coupling to sound. The results are used to assess radiation from a shell 6.4 ft long, 2.1 ft in radius, in the frequency range of about 100 to 300 cps. A survey of the modal properties indicates that radiation is due principally to (i) modes of gross motion of shell and end caps, and (ii) a few highly resonance, very poorly coupled lobar modes. The importance of the latter is determined by internal damping. A detailed analysis is given for the coupling of the lobar modes. (Author)

Descriptors :   *CYLINDRICAL BODIES), (*UNDERWATER SOUND, RESONANCE, VIBRATION, SHELLS(STRUCTURAL FORMS), MATHEMATICAL MODELS, KINETIC THEORY, MOTION, APPROXIMATION(MATHEMATICS), DAMPING, ACOUSTICS.

Subject Categories : Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE