Experimental studies of irregular water wave component interactions with comparisons to the hybrid wave model /
Waves in the oceans pose challenging problems to offshore structural design because they arc irregular and can be highly nonlinear. Although these irregular waves can be viewed as the summation of many linear wave components of different frequencies, accurate prediction of downstream surface elevat...
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| Format: | Thesis eBook |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
1993.
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| Subjects: | |
| Online Access: | Link to OAKTrust copy |
| Summary: | Waves in the oceans pose challenging problems to offshore structural design because they arc irregular and can be highly nonlinear. Although these irregular waves can be viewed as the summation of many linear wave components of different frequencies, accurate prediction of downstream surface elevations (wave evolution) and wave kinematics is difficult, due to nonlinear interactions among components. To account for component interactions a new Hybrid Wave Model is being developed. Its wave evolution predictions and kinematic estimates are compared with laboratory measurements in this study. Linear Random Wave Theory and accepted stretching techniques are compared as well. This study focuses on deep and intermediate water, unidirectional, irregular waves. Laboratory measurements of surface elevations and kinematics from four irregular wave trains. which were modeled after Pierson & Moskowitz and JONSWAP random wave spectra, are examined. Measurement equipment consists of resistance wave probes and a laser Doppler anemometer. Wave evolution data are compared with predictions from Linear Random Wave Theory and the Hybrid Wave Model. Velocity time series and extreme (largest) wave horizontal velocity profiles arc compared with estimates computed by Wheeler Stretching and Linear Extrapolation modifications to Linear Random Wave Theory and the Hybrid Wave Model. Extreme wave acceleration fields arc compared with Hybrid Wave Model acceleration fields only. Comparisons between measurements and model estimates demonstrate the Hybrid Wave Model's improvement to irregular wave evolution predictions and kinematics . The new model approximates wave evolution better than Linear Random Wave Theory in the majority of comparisons. Likewise, improved accuracy in Hybrid Wave Model velocity time series and extreme wave horizontal velocity profile estimates prove the model to be a valuable tool for offshore design. Acceleration comparisons illustrate the Hybrid Wave Model's ability to estimate local and total acceleration fields under two irregular wave trains extreme waves. Acceleration vector fields obtained from measurements and the Hybrid Wave Model are compared, and their magnitudes and directions show good agreement. |
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| Item Description: | "Major subject: Ocean Engineering". Vita. |
| Physical Description: | xiii, 106 leaves : illustrations ; 28 cm. Also available online. |
| Bibliography: | Includes bibliographical references. |