Accession Number : ADA187967

Title :   An Acoustic Bubble Density Measurement Technique for Surface Ship Waters.

Descriptive Note : Master's thesis,

Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CA

Personal Author(s) : Hampton, Stephen W

PDF Url : ADA187967

Report Date : 30 Sep 1987

Pagination or Media Count : 187

Abstract : The Dual Frequency Pump Method of acoustically determining point by point bubble cloud densities was studied to determine the practicality of using this acoustic technique to determine bubble densities in surface ship wakes. The dual frequency technique of acoustically detecting bubbles utilizes a high and low frequency sound field to insonify the target bubbles. The bubbles themselves then radiate sound at the sidebands of higher frequency. The frequency of the return sound is proportional to the bubble sizes present. The Dual Frequency Pump Method of bubble detection can differentiate and count many different sized bubbles and is, therefore, well suited for determining ship wake bubble density distributions. The theory, considerations, experimental results, and recommendations of this thesis support the application of the dual frequency acoustic techniques to the ship wake problem. Keywords: Theses; Acoustic bubble density measurement; Surface ship wakes; Bubble resonance; Dual frequency bubble detection; Ultrasonic bubble detection.

Descriptors :   *ACOUSTIC DETECTION, *BUBBLES, *ACOUSTIC MEASUREMENT, *WAKE, ACOUSTIC FIELDS, ACOUSTIC RESONANCE, CLOUDS, DENSITY, DETECTION, DUAL MODE, FREQUENCY, HIGH FREQUENCY, LOW FREQUENCY, OCEAN SURFACE, PUMPS, SHIPS, SIDEBANDS, SIZES(DIMENSIONS), SURFACE WATERS, THESES, ULTRASONIC FREQUENCIES, RESONANT FREQUENCY, EXCITATION, COMPUTER PROGRAMS, SOUND PRESSURE, ACOUSTIC IMAGES

Subject Categories : Acoustic Detection and Detectors
      Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE