Accession Number:

ADA361263

Title:

Geometrical Aspects of Scattering and Physical Effects of Sound

Descriptive Note:

Annual summary rept. 1 Jun 97-31 May 98

Corporate Author:

WASHINGTON STATE UNIV PULLMAN DEPT OF PHYSICS

Personal Author(s):

• Marston, Philip L.

Report Date:

1998-06-08

Pagination or Media Count:

18.0

Abstract:

Research is reported primarily in the following areas 1 High-frequency enhancements of the backscattering of sound by tilted empty and water-filled blunt elastic cylindrical shells in water are calculated and observed. The leaky-wave contributions to backscattering were studied and were also studied for a solid stainless-steel cylinder. A different type of backscattering enhancement was also studied for penetrable cylinders e.g. plastics supporting low-velocity waves. This enhancement is associated with a caustic-merging transition which was also confirmed with an analogous light scattering experiment. 2 The coupling of oscillating magnetic fields to the torsional modes of a stainless steel spherical shell in water was investigated. Sound radiated by the magnetically excited modes is detected and resonances are identified. 3 Some predicted properties of helicoidal ultrasonic waves were confirmed using a novel PVDF transducer. These waves have an axial null and have potential applications in scattering and alignment and they carry orbital angular momentum. Other research summarized concerns 4 acoustical-scattering analogs studied with light and 5 the acoustical probing of dilute aqueous suspensions of particles using radiation pressure.

Descriptors:

• *RAYLEIGH SCATTERING
• *ACOUSTIC SCATTERING
• LIGHT SCATTERING
• MAGNETIC FIELDS
• HIGH FREQUENCY
• BACKSCATTERING
• UNDERWATER ACOUSTICS
• RADIATION PRESSURE
• ULTRASONIC RADIATION
• ACOUSTIC RESONANCE
• ELASTIC SHELLS

Subject Categories:

• Acoustics
• Optics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE