### Abstract

Theoretical and laboratory studies are performed to analyze the wave attenuation phenomenon over fluid mud under current. In the theoretical part, a semi-empirical formula is derived to model the attenuation process under current. Based on the linear wave theory, the change of wave amplitude is related with the averaged damping effect of the muddy bed. By solving a differential equation, the exponential decay of the wave amplitude is confirmed. A function called damping function is used in the formula, and it is expanded into a series of wave parameters and some undetermined coefficients called auxiliary damping factors. Based on the assumption that the mud properties do not change under current, the formula is combined with the dispersion relation for linear wave under uniform current to describe the attenuation process under current. Laboratory experiments are conducted first without current. The data of wave attenuation are collected and inserted to the formula obtained in the theoretical analysis to figure out the values of the auxiliary damping factors. The second set of experiments is conducted under current and the collected data are compared with the calculated values obtained by using the newly proposed formula with the dispersion relation. The result of comparison shows good applicability of the new formula to the wave attenuation under current.

Original language | English |
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Title of host publication | ASIAN AND PACIFIC COASTS 2017 |

Publisher | World Scientific Publishing Co. Pte Ltd |

Pages | 34-43 |

Number of pages | 10 |

Edition | 213039 |

ISBN (Print) | 9789813233805 |

Publication status | Published - 2018 Jan 1 |

Event | 9th International Conference on Asian and Pacific Coasts, APAC 2017 - Pasay, Philippines Duration: 2017 Oct 19 → 2017 Oct 21 |

### Other

Other | 9th International Conference on Asian and Pacific Coasts, APAC 2017 |
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Country | Philippines |

City | Pasay |

Period | 17/10/19 → 17/10/21 |

### Fingerprint

### Keywords

- Fluid mud
- Semi-empirical formula
- Wave attenuation

### ASJC Scopus subject areas

- Earth-Surface Processes
- Oceanography

### Cite this

*ASIAN AND PACIFIC COASTS 2017*(213039 ed., pp. 34-43). World Scientific Publishing Co. Pte Ltd.

**A semi-empirical formula for wave attenuation over muddy bed under current.** / Xie, Wenang; Shibayama, Tomoya.

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

*ASIAN AND PACIFIC COASTS 2017.*213039 edn, World Scientific Publishing Co. Pte Ltd, pp. 34-43, 9th International Conference on Asian and Pacific Coasts, APAC 2017, Pasay, Philippines, 17/10/19.

}

TY - GEN

T1 - A semi-empirical formula for wave attenuation over muddy bed under current

AU - Xie, Wenang

AU - Shibayama, Tomoya

PY - 2018/1/1

Y1 - 2018/1/1

N2 - Theoretical and laboratory studies are performed to analyze the wave attenuation phenomenon over fluid mud under current. In the theoretical part, a semi-empirical formula is derived to model the attenuation process under current. Based on the linear wave theory, the change of wave amplitude is related with the averaged damping effect of the muddy bed. By solving a differential equation, the exponential decay of the wave amplitude is confirmed. A function called damping function is used in the formula, and it is expanded into a series of wave parameters and some undetermined coefficients called auxiliary damping factors. Based on the assumption that the mud properties do not change under current, the formula is combined with the dispersion relation for linear wave under uniform current to describe the attenuation process under current. Laboratory experiments are conducted first without current. The data of wave attenuation are collected and inserted to the formula obtained in the theoretical analysis to figure out the values of the auxiliary damping factors. The second set of experiments is conducted under current and the collected data are compared with the calculated values obtained by using the newly proposed formula with the dispersion relation. The result of comparison shows good applicability of the new formula to the wave attenuation under current.

AB - Theoretical and laboratory studies are performed to analyze the wave attenuation phenomenon over fluid mud under current. In the theoretical part, a semi-empirical formula is derived to model the attenuation process under current. Based on the linear wave theory, the change of wave amplitude is related with the averaged damping effect of the muddy bed. By solving a differential equation, the exponential decay of the wave amplitude is confirmed. A function called damping function is used in the formula, and it is expanded into a series of wave parameters and some undetermined coefficients called auxiliary damping factors. Based on the assumption that the mud properties do not change under current, the formula is combined with the dispersion relation for linear wave under uniform current to describe the attenuation process under current. Laboratory experiments are conducted first without current. The data of wave attenuation are collected and inserted to the formula obtained in the theoretical analysis to figure out the values of the auxiliary damping factors. The second set of experiments is conducted under current and the collected data are compared with the calculated values obtained by using the newly proposed formula with the dispersion relation. The result of comparison shows good applicability of the new formula to the wave attenuation under current.

KW - Fluid mud

KW - Semi-empirical formula

KW - Wave attenuation

UR - http://www.scopus.com/inward/record.url?scp=85048197638&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85048197638&partnerID=8YFLogxK

M3 - Conference contribution

AN - SCOPUS:85048197638

SN - 9789813233805

SP - 34

EP - 43

BT - ASIAN AND PACIFIC COASTS 2017

PB - World Scientific Publishing Co. Pte Ltd

ER -