Microbubble Size Distributions Data Collection and Analysis
Abstract
A technique for determining the size distribution of micron-size bubbles from underway measurements at sea is described. A camera designed for photographing micron-size plankton was leased from Dr. Harold Edgerton, M.I.T. The camera was housed in a foil-shaped housing for submerged underway operations~ the unit was tested with ship speeds of up to 6 meters/sec \20112 knots\202. Selected frames of the film were used to determine the feasibility of using a specialized computerized image analysis system for bubble size analysis; this system is owned by Bete-Fog Nozzle, Inc., Greenfield, MA. Stored threshold criteria eliminated much of the potential errors associated with the manual subjective assignment of in-focus, single bubbles. Images of aggregates, or clouds, of less than 50 micron to about 900 micron size bubbles were interactively processed and analyzed in very short time periods. This approach proved superior to the standard manual counting method. A Bete-Fog high-resolution video camera system was tested for underwater use and appears to be a suitable replacement for the film-camera technique for bubble diameters greater than five microns. Also, the video system is directly compatible with the computerized image analysis system, and, it provides real-time monitoring at sea.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 14, 1985
- Accession Number
- ADA631366
Entities
People
- James J. Gallagher
Organizations
- Naval Facilities Engineering Systems Command