Accession Number:

AD0847671

Title:

Sound Radiated by Spheres Falling in Poly (Ethylene Oxide) Solutions.

Descriptive Note:

Master's thesis,

Corporate Author:

NAVAL POSTGRADUATE SCHOOL MONTEREY CA

Personal Author(s):

• Sendek, Joseph Michael

Report Date:

1968-09-01

Pagination or Media Count:

45.0

Abstract:

Sound radiated by spheres freely falling in aqueous solutions of polyethylene oxide at concentrations 0 and 100 wppm was investigated. In solution of 0 wppm concentration, only those spheres with calculated Reynolds numbers based on the terminal speed at or above the critical value radiated sufficient energy to be detected above the background. This sound consisted of frequent, distinct noise bursts. In the 100 wppm solution, all spheres with Reynolds numbers near the critical value displayed an increase in speed and a reduction of radiant sound to below background. The one sphere definitely in the supercritical region did not significantly change in speed, and the radiant sound was not reduced as much as for the other spheres. These observations are consistent with the assumption that the noise bursts are produced in the wake associated with laminar separation, and with the previous observation that polymer addition shifts the critical Reynolds number to higher values. Author

Descriptors:

• *UNDERWATER PROJECTILES
• *TURBULENT BOUNDARY LAYER
• TURBULENCE
• NOISE
• SPHERES
• EPOXY RESINS
• DRAG
• REDUCTION
• MATHEMATICAL MODELS
• REYNOLDS NUMBER
• WAKE
• BLUNT BODIES
• FLOW SEPARATION
• ADDITIVES
• THESES

Subject Categories:

• Ammunition and Explosives
• Acoustics
• Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE