### Abstract

A new approach to investigate the hydrodynamic forces acting on a vertical cylinder in random waves is presented. The time series of random wave force is obtained from numerical simulation of a two-dimensional irregular oscillating flow around a circular cylinder by numerical solution of the incompressible Navier-Stokes equation expressed in a generalized coordinate system through the use of the MAC method. The random waves are chosen from laboratory experimental data. To obtain the Morison force coefficients, two methods are used: least squares fit of total force time series and least squares fit on a wave-by-wave basis. The phenomena found in calculated results are similar to those in the experiments, and the study revealed that the so-called history effect of random wave forces is mainly due to the vortex shedding, which is confirmed by computed flow patterns.

Original language | English |
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Pages (from-to) | 278-283 |

Number of pages | 6 |

Journal | International Journal of Offshore and Polar Engineering |

Volume | 4 |

Issue number | 4 |

Publication status | Published - Dec 1994 |

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### All Science Journal Classification (ASJC) codes

- Civil and Structural Engineering
- Mechanical Engineering
- Ocean Engineering

### Cite this

*International Journal of Offshore and Polar Engineering*,

*4*(4), 278-283.

**Study on random wave force coefficients using numerical simulation of flow fields.** / Hu, Changhong; Koterayama, Wataru.

Research output: Contribution to journal › Article

*International Journal of Offshore and Polar Engineering*, vol. 4, no. 4, pp. 278-283.

}

TY - JOUR

T1 - Study on random wave force coefficients using numerical simulation of flow fields

AU - Hu, Changhong

AU - Koterayama, Wataru

PY - 1994/12

Y1 - 1994/12

N2 - A new approach to investigate the hydrodynamic forces acting on a vertical cylinder in random waves is presented. The time series of random wave force is obtained from numerical simulation of a two-dimensional irregular oscillating flow around a circular cylinder by numerical solution of the incompressible Navier-Stokes equation expressed in a generalized coordinate system through the use of the MAC method. The random waves are chosen from laboratory experimental data. To obtain the Morison force coefficients, two methods are used: least squares fit of total force time series and least squares fit on a wave-by-wave basis. The phenomena found in calculated results are similar to those in the experiments, and the study revealed that the so-called history effect of random wave forces is mainly due to the vortex shedding, which is confirmed by computed flow patterns.

AB - A new approach to investigate the hydrodynamic forces acting on a vertical cylinder in random waves is presented. The time series of random wave force is obtained from numerical simulation of a two-dimensional irregular oscillating flow around a circular cylinder by numerical solution of the incompressible Navier-Stokes equation expressed in a generalized coordinate system through the use of the MAC method. The random waves are chosen from laboratory experimental data. To obtain the Morison force coefficients, two methods are used: least squares fit of total force time series and least squares fit on a wave-by-wave basis. The phenomena found in calculated results are similar to those in the experiments, and the study revealed that the so-called history effect of random wave forces is mainly due to the vortex shedding, which is confirmed by computed flow patterns.

UR - http://www.scopus.com/inward/record.url?scp=0028700101&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0028700101&partnerID=8YFLogxK

M3 - Article

VL - 4

SP - 278

EP - 283

JO - International Journal of Offshore and Polar Engineering

JF - International Journal of Offshore and Polar Engineering

SN - 1053-5381

IS - 4

ER -