Accession Number : AD0704159

Title :   EXPERIMENTAL VERIFICATION AND VISUALIZATION OF CREEPING WAVES FOR ACOUSTIC SCATTERING BY RIGID BODIES IN AIR.

Descriptive Note : Final rept.,

Corporate Author : TEMPLE UNIV PHILADELPHIA PA DEPT OF PHYSICS

Personal Author(s) : Steinberg,Bruce N. ; Harbold,Mary L.

Report Date : FEB 1970

Pagination or Media Count : 46

Abstract : Application of the mathematical technique known as the Sommerfeld-Watson transformation to the normal-mode solution of scattering problems led to the physical interpretation of 'creeping waves' by Franz who calculated their phase velocity and attenuation. The first direct experimental verification of these conclusions was performed in this laboratory, for acoustic waves in air by using acoustic transducers imbedded in the surface of rigid bodies. Later experiments extended the techniques by using coincidence methods with optical detectors for laser beams reflected from the surface. Holographic studies were also attempted for the region just outside the scatterer by use of two-beam interferometry of the Mach-Zehnder type. (Author)

Descriptors :   (*SOUND, SCATTERING), DIFFRACTION, CYLINDRICAL BODIES, INTERFEROMETERS, LASERS, STEREOPHOTOGRAPHY

Subject Categories : Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE