Bubble injection under breaking waves
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Authors
Tannahill, James B.
Subjects
Bubble Injection
Void Fraction
Energy Dissipation
Wave Transformation
Void Fraction
Energy Dissipation
Wave Transformation
Advisors
Thornton, Edward B.
Stanton, Timothy P.
Date of Issue
1996-12
Date
Publisher
Monterey, California. Naval Postgraduate School
Language
en_US
Abstract
Wave energy dissipation due to bubble penetration and inferred turbulent penetration from breaking waves in the surf zone is related to the total energy of dissipation. Bubble injection is inferred from void fraction measurements obtained using a 2.3 meter vertical array of eight conductivity sensors extending from the bottom through the water surface. Potential energy and dissipation associated with bubble injection are calculated and compared with total wave dissipation. Total wave dissipation is calculated from the energy flux balance measured using an array of seven pressure sensors in the surf zone. Percent of total wave potential energy of the bubbles due to spilling breakers is on the order of 0.18% to 0.62%, consistent with past measurements in the surf zone. Percent of the bubble potential energy dissipation rates to total wave dissipation in the cross shore direction is on the order of 8% to 20%. The potential energy dissipation is largest immediately after injection, decaying exponentially after that. Bubble potential energy dissipation results within 1.2 seconds even for void fraction events greater than 36% and usually in less than 1.0 seconds. Energy dissipation was found linearly related (0.95 correlation coefficient) with the ratios of wave height to water depth, a measure of the percent of breaking waves within the surf zone
Type
Thesis
Description
Series/Report No
Department
Oceanography
Organization
Identifiers
NPS Report Number
Sponsors
Funder
Format
xiv, 41 p.
Citation
Distribution Statement
Approved for public release; distribution is unlimited.
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.