Accession Number : AD0630033

Title :   NUMERICAL DISCUSSION OF CREEPING ACOUSTICAL WAVES AROUND CYLINDERS. SOUND SCATTERING BY ELASTIC CYLINDRICAL SHELLS,

Descriptive Note : Rept. for Underwater Acoustics Program,

Corporate Author : CATHOLIC UNIV OF AMERICA WASHINGTON D C

Personal Author(s) : Uberall,H. ; Doolittle,R. D. ; McNicholas,J. V.

Report Date : DEC 1965

Pagination or Media Count : 29

Abstract : The report presents the solution for the scattered field corresponding to a plane sound wave incident upon an infinite elastic circular-cylindrical concentric shell, imbedded in a fluid and enclosing another fluid. The results are shown to contain the known special cases of fluid and elastic solid cylinders. Furthermore, limiting expressions for long wavelengths are obtained in special cases. The second part of this report is a sequel to a previous report (AD-625 793) 'Pulsed Creeping Waves in Acoustics', which discussed diffraction of sound waves and pulses by cylinders. Graphical illustrations are presented of some aspects of the creeping waves, in particular their velocities and damping for rigid and soft cylinders, the backscattering cross section for rigid cylinders, and the shape of the head of the diffracted pulses. It is found that only very few creeping waves already give an excellent approximation to the exact solution for large and even moderately large values of ka. (Author)

Descriptors :   (*ACOUSTICS, CYLINDRICAL BODIES), (*SOUND, SCATTERING), SOUND TRANSMISSION, DIFFRACTION, ELASTIC PROPERTIES, SOLIDS, FLUIDS

Subject Categories : Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE