Acoustical Emission from Bubbles
Abstract
The scientific objectives of this report are to investigate the dynamics of bubbles formed from a free surface (particularly the upper surface of the ocean) by breaking waves, and the resulting emission of underwater sound. The chief natural source of underwater sound in the ocean at frequencies from 0. 5 to 50 kHz is known to be the acoustical emission from newly-formed bubbles and bubble clouds, particularly those created by breaking waves and rain. Attention has been drawn to the occurrence of high-speed jets directed into the bubble just after bubble closure. They have been observed both in rain-drop impacts and in the release of bubbles from an underwater nozzle. Qualitatively they are similar to the inward jets seen in the collapse of a cavitation bubble. There is also a similarity to the highly-accelerated upward jets in standing water waves (accelerations > 20g) or in bubbles bursting at a free surface. We have adopted a theoretical approach based on the dynamics of incompressible fluids with a free surface.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 31, 1991
- Accession Number
- ADA252390
Entities
People
- Michael S. Longuet-higgins
Organizations
- University of California, San Diego