### Abstract

Original language | English |
---|---|

Pages (from-to) | 121-136 |

Number of pages | 16 |

Journal | Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment |

Volume | 223 |

Issue number | 1 |

DOIs | |

Publication status | Published - 19 Dec 2008 |

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### Keywords

- morison equation
- rectangular cylinder
- wave and current force
- drag and inertia coefficients
- low keulegan–carpenter number

### Cite this

*Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment*,

*223*(1), 121-136. https://doi.org/10.1243/14750902JEME124

}

*Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment*, vol. 223, no. 1, pp. 121-136. https://doi.org/10.1243/14750902JEME124

**Drag and inertia coefficients for horizontally submerged rectangular cylinders in waves and currents.** / Venugopal, V.; Varyani, K.S.; Westlake, P.C.

Research output: Contribution to journal › Article

TY - JOUR

T1 - Drag and inertia coefficients for horizontally submerged rectangular cylinders in waves and currents

AU - Venugopal, V.

AU - Varyani, K.S.

AU - Westlake, P.C.

PY - 2008/12/19

Y1 - 2008/12/19

N2 - The results of an experimental investigation carried out to measure combined wave and current loads on horizontally submerged square and rectangular cylinders are reported in this paper. The wave and current induced forces on a section of the cylinders with breadth-depth (aspect) ratios equal to 1, 0.5, and 0.75 are measured in a wave tank. The maximum value of Keulegan-Carpenter (KC) number obtained in waves alone is about 5 and Reynolds (Re) number ranged from 6.3976103 to 1.186105. The drag (CD) and inertia (CM) coefficients for each cylinder are evaluated using measured sectional wave forces and particle kinematics calculated from linear wave theory. The values of CD and CM obtained for waves alone have already been reported (Venugopal, V., Varyani, K. S., and Barltrop, N. D. P. Wave force coefficients for horizontally submerged rectangular cylinders. Ocean Engineering, 2006, 33, 11-12, 1669-1704) and the coefficients derived in combined waves and currents are presented here. The results indicate that both drag and inertia coefficients are strongly affected by the presenceof the current and show different trends for different cylinders. The values of the vertical component inertia coefficients (CMY) in waves and currents are generally smaller than the inertia coefficients obtained in waves alone, irrespective of the current's magnitude and direction. The results also illustrate the effect of a cylinder's aspect ratio on force coefficients. This study will be useful in the design of offshore structures whose columns and caissons are rectangular sections.

AB - The results of an experimental investigation carried out to measure combined wave and current loads on horizontally submerged square and rectangular cylinders are reported in this paper. The wave and current induced forces on a section of the cylinders with breadth-depth (aspect) ratios equal to 1, 0.5, and 0.75 are measured in a wave tank. The maximum value of Keulegan-Carpenter (KC) number obtained in waves alone is about 5 and Reynolds (Re) number ranged from 6.3976103 to 1.186105. The drag (CD) and inertia (CM) coefficients for each cylinder are evaluated using measured sectional wave forces and particle kinematics calculated from linear wave theory. The values of CD and CM obtained for waves alone have already been reported (Venugopal, V., Varyani, K. S., and Barltrop, N. D. P. Wave force coefficients for horizontally submerged rectangular cylinders. Ocean Engineering, 2006, 33, 11-12, 1669-1704) and the coefficients derived in combined waves and currents are presented here. The results indicate that both drag and inertia coefficients are strongly affected by the presenceof the current and show different trends for different cylinders. The values of the vertical component inertia coefficients (CMY) in waves and currents are generally smaller than the inertia coefficients obtained in waves alone, irrespective of the current's magnitude and direction. The results also illustrate the effect of a cylinder's aspect ratio on force coefficients. This study will be useful in the design of offshore structures whose columns and caissons are rectangular sections.

KW - morison equation

KW - rectangular cylinder

KW - wave and current force

KW - drag and inertia coefficients

KW - low keulegan–carpenter number

U2 - 10.1243/14750902JEME124

DO - 10.1243/14750902JEME124

M3 - Article

VL - 223

SP - 121

EP - 136

JO - Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment

JF - Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment

SN - 1475-0902

IS - 1

ER -