3-D numerical modelling of greenwater loading on fixed ship-shaped FPSOs

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Abstract

This work is focused on the assessment of greenwater overtopping onto fixed ship-shaped FPSO models using three dimensional (3-D) Computational Fluid Dynamics (CFD) simulations. Good agreement between the numerical results and published experimental data from Barcellona et al. (2003) indicates that 3-D CFD is an effective tool which may be used to assess greenwater associated with an incident wave group. Different wall-sided bow shapes are investigated numerically, and the results provide insight into how the bow shape influences the evolution of on-deck flows, and the horizontal force on a vertical wall spanning the full deck width for incident waves approaching normal to the bow. It is found that the horizontal force, thus, the horizontal momentum of greenwater flows, is a result of the combined action of water-front velocities and the corresponding water volume impacting on the structures. For the bow shapes considered in this study, although clear differences in on-deck flow are observed for different bow shape, differences in force on the vertical wall are relatively small. Simulations for a 2-D vertical rectangular box that has the same longitudinal section as the 3-D model FPSOs give somewhat similar results to 3-D predictions along the centre-line. This similarity may be due partly to the fact that increases in on-deck flow velocity due to increased freeboard exceedance in the 2-D simulations compensates for a lack of focusing of the on-deck flow observed in the 3-D simulations. This finding has implications for understanding how computationally cheaper 2-D greenwater simulations relate to more realistic 3-D greenwater events. (C) 2018 Elsevier Ltd. All rights reserved.

Original languageEnglish
Pages (from-to)283-301
Number of pages19
JournalJournal of Fluids and Structures
Volume84
DOIs
Publication statusPublished - Jan 2019

Cite this

@article{ed419b6b2c744fe4a99b49bbb69d2c1a,
title = "3-D numerical modelling of greenwater loading on fixed ship-shaped FPSOs",
abstract = "This work is focused on the assessment of greenwater overtopping onto fixed ship-shaped FPSO models using three dimensional (3-D) Computational Fluid Dynamics (CFD) simulations. Good agreement between the numerical results and published experimental data from Barcellona et al. (2003) indicates that 3-D CFD is an effective tool which may be used to assess greenwater associated with an incident wave group. Different wall-sided bow shapes are investigated numerically, and the results provide insight into how the bow shape influences the evolution of on-deck flows, and the horizontal force on a vertical wall spanning the full deck width for incident waves approaching normal to the bow. It is found that the horizontal force, thus, the horizontal momentum of greenwater flows, is a result of the combined action of water-front velocities and the corresponding water volume impacting on the structures. For the bow shapes considered in this study, although clear differences in on-deck flow are observed for different bow shape, differences in force on the vertical wall are relatively small. Simulations for a 2-D vertical rectangular box that has the same longitudinal section as the 3-D model FPSOs give somewhat similar results to 3-D predictions along the centre-line. This similarity may be due partly to the fact that increases in on-deck flow velocity due to increased freeboard exceedance in the 2-D simulations compensates for a lack of focusing of the on-deck flow observed in the 3-D simulations. This finding has implications for understanding how computationally cheaper 2-D greenwater simulations relate to more realistic 3-D greenwater events. (C) 2018 Elsevier Ltd. All rights reserved.",
keywords = "Greenwater, Fixed ship-shaped FPSOs, 3-D numerical modelling, OpenFOAM, WATER LOADS, SEAKEEPING ANALYSIS, QUARTERING SEAS, DECK, SIMULATION, IMPACT, FLOW, BOW, PROBABILITY, PREDICTION",
author = "Lifen Chen and Taylor, {Paul H.} and Scott Draper and Hugh Wolgamot",
year = "2019",
month = "1",
doi = "10.1016/j.jfluidstructs.2018.11.003",
language = "English",
volume = "84",
pages = "283--301",
journal = "Journal of Fluids and Structures",
issn = "0889-9746",
publisher = "Academic Press",

}

TY - JOUR

T1 - 3-D numerical modelling of greenwater loading on fixed ship-shaped FPSOs

AU - Chen, Lifen

AU - Taylor, Paul H.

AU - Draper, Scott

AU - Wolgamot, Hugh

PY - 2019/1

Y1 - 2019/1

N2 - This work is focused on the assessment of greenwater overtopping onto fixed ship-shaped FPSO models using three dimensional (3-D) Computational Fluid Dynamics (CFD) simulations. Good agreement between the numerical results and published experimental data from Barcellona et al. (2003) indicates that 3-D CFD is an effective tool which may be used to assess greenwater associated with an incident wave group. Different wall-sided bow shapes are investigated numerically, and the results provide insight into how the bow shape influences the evolution of on-deck flows, and the horizontal force on a vertical wall spanning the full deck width for incident waves approaching normal to the bow. It is found that the horizontal force, thus, the horizontal momentum of greenwater flows, is a result of the combined action of water-front velocities and the corresponding water volume impacting on the structures. For the bow shapes considered in this study, although clear differences in on-deck flow are observed for different bow shape, differences in force on the vertical wall are relatively small. Simulations for a 2-D vertical rectangular box that has the same longitudinal section as the 3-D model FPSOs give somewhat similar results to 3-D predictions along the centre-line. This similarity may be due partly to the fact that increases in on-deck flow velocity due to increased freeboard exceedance in the 2-D simulations compensates for a lack of focusing of the on-deck flow observed in the 3-D simulations. This finding has implications for understanding how computationally cheaper 2-D greenwater simulations relate to more realistic 3-D greenwater events. (C) 2018 Elsevier Ltd. All rights reserved.

AB - This work is focused on the assessment of greenwater overtopping onto fixed ship-shaped FPSO models using three dimensional (3-D) Computational Fluid Dynamics (CFD) simulations. Good agreement between the numerical results and published experimental data from Barcellona et al. (2003) indicates that 3-D CFD is an effective tool which may be used to assess greenwater associated with an incident wave group. Different wall-sided bow shapes are investigated numerically, and the results provide insight into how the bow shape influences the evolution of on-deck flows, and the horizontal force on a vertical wall spanning the full deck width for incident waves approaching normal to the bow. It is found that the horizontal force, thus, the horizontal momentum of greenwater flows, is a result of the combined action of water-front velocities and the corresponding water volume impacting on the structures. For the bow shapes considered in this study, although clear differences in on-deck flow are observed for different bow shape, differences in force on the vertical wall are relatively small. Simulations for a 2-D vertical rectangular box that has the same longitudinal section as the 3-D model FPSOs give somewhat similar results to 3-D predictions along the centre-line. This similarity may be due partly to the fact that increases in on-deck flow velocity due to increased freeboard exceedance in the 2-D simulations compensates for a lack of focusing of the on-deck flow observed in the 3-D simulations. This finding has implications for understanding how computationally cheaper 2-D greenwater simulations relate to more realistic 3-D greenwater events. (C) 2018 Elsevier Ltd. All rights reserved.

KW - Greenwater

KW - Fixed ship-shaped FPSOs

KW - 3-D numerical modelling

KW - OpenFOAM

KW - WATER LOADS

KW - SEAKEEPING ANALYSIS

KW - QUARTERING SEAS

KW - DECK

KW - SIMULATION

KW - IMPACT

KW - FLOW

KW - BOW

KW - PROBABILITY

KW - PREDICTION

U2 - 10.1016/j.jfluidstructs.2018.11.003

DO - 10.1016/j.jfluidstructs.2018.11.003

M3 - Article

VL - 84

SP - 283

EP - 301

JO - Journal of Fluids and Structures

JF - Journal of Fluids and Structures

SN - 0889-9746

ER -