Irregular wave kinematics in the surf zone /
Experiments are performed in a two-dimensional wave tank with
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| Format: | Thesis Book |
| Language: | English |
| Published: |
[Place of publication not identified] :
[publisher not identified] ;
1995.
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| Subjects: | |
| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=742164181&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | Experiments are performed in a two-dimensional wave tank with a sloping beach at one end. Irregular waves are generated and the water particle velocity measured under the breaking waves with a laser Doppler velocimeter. Water surface elevations are measured with resistance type wave gages. Water surface profiles are filmed with a videocassette recorder. The time averaged features throughout the entire surf zone are analyzed. The undertow, set-up and wave height statistics are calculated. Comparisons are made between plunging and spilling wave conditions. Low frequency waves have a significant effect on the surf zone dynamics and on measurements of the set-up, undertow and wave height statistics. Plunging waves are found to have a narrower surf zone and steeper set-up than wave conditions dominated by spilling type breakers. The undertow in the surf zone is not substantially different between the irregular wave spilling and plunging conditions. Also, the undertow magnitude is approximately uniform throughout the water column, in contrast with the more curved distribution reported for regular wave experiments. Using ensemble averaging, time series of turbulent parameters in the Reynolds averaged energy and momentum equations are calculated and described. In addition plots of the joint distribution of the different terms in the energy equation were examined. The probability distribution plots show weak correlations and confirm that all the analyzed terms in the energy equation are of the same order of magnitude at at least some of the time. The correlations between the turbulent kinetic energy and the mean flow may help explain why plunging waves tend to erode a beach while spilling waves accrete. |
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| Item Description: | Vita. "Major Subject: Ocean Engineering". |
| Physical Description: | xiii, 135 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilms Inc. |
| Bibliography: | Includes bibliographical references. |