### Abstract

Language | English |
---|---|

Pages | 595-604 |

Number of pages | 10 |

Journal | Ocean Engineering |

Volume | 36 |

Issue number | 8 |

DOIs | |

Status | Published - Jun 2009 |

### Fingerprint

### Keywords

- Wave transformation
- Vertical cylinder
- Wavelet-based bicoherence
- Scale-averaged wavelet energy
- Higher-harmonic forces
- Nonlinear interactions

### Cite this

**Higher-harmonic focused-wave forces on a vertical cylinder.** / Ma, Yuxiang; Dong, Guohai; Perlin, Marc; Liu, Shuxue; Zang, Jun; Sun, Yiyan.

Research output: Contribution to journal › Article

*Ocean Engineering*, vol. 36, no. 8, pp. 595-604. DOI: 10.1016/j.oceaneng.2009.02.009

}

TY - JOUR

T1 - Higher-harmonic focused-wave forces on a vertical cylinder

AU - Ma,Yuxiang

AU - Dong,Guohai

AU - Perlin,Marc

AU - Liu,Shuxue

AU - Zang,Jun

AU - Sun,Yiyan

PY - 2009/6

Y1 - 2009/6

N2 - This paper considers higher-harmonic forces due to wave focusing on a vertical circular cylinder. A series of experiments has been conducted in a wave flume. The first six-harmonic components of the measured wave forces are analyzed using the scale-averaged wavelet spectrum. It is noted that due to the transient nature of focused (freak) waves, Fourier analysis would not provide equivalent information to that gleaned from the analyses used herein. The results for the experiments with very steep wave crests show significant amplitudes at the fourth and fifth harmonics. These harmonics exhibit amplitudes that are the same order as the second harmonic, but much larger than those of the third harmonic. The wavelet-based bicoherence is used to detect the quadratic nonlinearity of the measured forces. And the bicoherence spectra reveal the primary mathematical reason for the existence of the striking amplitudes of the fourth and fifth harmonics: the interaction between the lower-harmonic components couple more strongly with the fourth and fifth harmonics, thus the fourth and fifth harmonics glean more energy than those of the third-harmonic components. However, the physical explanation for this remains elusive.

AB - This paper considers higher-harmonic forces due to wave focusing on a vertical circular cylinder. A series of experiments has been conducted in a wave flume. The first six-harmonic components of the measured wave forces are analyzed using the scale-averaged wavelet spectrum. It is noted that due to the transient nature of focused (freak) waves, Fourier analysis would not provide equivalent information to that gleaned from the analyses used herein. The results for the experiments with very steep wave crests show significant amplitudes at the fourth and fifth harmonics. These harmonics exhibit amplitudes that are the same order as the second harmonic, but much larger than those of the third harmonic. The wavelet-based bicoherence is used to detect the quadratic nonlinearity of the measured forces. And the bicoherence spectra reveal the primary mathematical reason for the existence of the striking amplitudes of the fourth and fifth harmonics: the interaction between the lower-harmonic components couple more strongly with the fourth and fifth harmonics, thus the fourth and fifth harmonics glean more energy than those of the third-harmonic components. However, the physical explanation for this remains elusive.

KW - Wave transformation

KW - Vertical cylinder

KW - Wavelet-based bicoherence

KW - Scale-averaged wavelet energy

KW - Higher-harmonic forces

KW - Nonlinear interactions

UR - http://www.scopus.com/inward/record.url?scp=67349269995&partnerID=8YFLogxK

UR - http://dx.doi.org/10.1016/j.oceaneng.2009.02.009

U2 - 10.1016/j.oceaneng.2009.02.009

DO - 10.1016/j.oceaneng.2009.02.009

M3 - Article

VL - 36

SP - 595

EP - 604

JO - Ocean Engineering

T2 - Ocean Engineering

JF - Ocean Engineering

SN - 0029-8018

IS - 8

ER -