ADV measurements of blockage flow effects near a model jacket in waves and current

A.J. Archer; H.A. Wolgamot; J. Orszaghova; S. Dai; P.H. Taylor

doi:10.1016/j.jfluidstructs.2024.104076

ADV measurements of blockage flow effects near a model jacket in waves and current

A.J. Archer, H.A. Wolgamot, J. Orszaghova, S. Dai, P.H. Taylor

Naval Architecture, Ocean And Marine Engineering

Research output: Contribution to journal › Article › peer-review

2 Citations (Scopus)

25 Downloads (Pure)

Abstract

Design standards for drag loading on offshore jacket structures do not presently account for the reduction in forces arising from flow blockage effects in the event of combined waves and current. This force reduction is believed to originate in reduced mean flow velocity through the jacket, but this has never been directly measured. To address this, we conducted physical-model tests which measured the flow adjacent to a jacket structure in combined waves and in-line currents using acoustic Doppler velocimeters. Results confirm a dramatic reduction in the mean flow velocity up-wave and down-wave of a model jacket in waves and current, far greater than the flow reduction observed in current alone. These results unambiguously confirm the significant additional blockage (and hence reduction in structural loads) not captured in current offshore design standards.

Original language	English
Article number	104076
Number of pages	14
Journal	Journal of Fluids and Structures
Volume	125
Early online date	18 Jan 2024
DOIs	https://doi.org/10.1016/j.jfluidstructs.2024.104076
Publication status	Published - 31 Mar 2024

Funding

The authors acknowledge support from the ARC ITRH for Transforming energy Infrastructure through Digital Engineering, Australia (TIDE, http://TIDE.edu.au ) which is led by The University of Western Australia, delivered with The University of Wollongong and several other Australian and International research partners, and funded by the Australian Research Council, Australia , INPEX Operations Australia , Shell Australia , Woodside Energy, Australia , Fugro Australia Marine, Australia , Wood Group Kenny Australia , RPS Group, Australia , Bureau Veritas, Australia and Lloyd’s Register Global Technology, Australia (Grant No. IH200100009 ). The authors are grateful to Mike Efthymiou and Peter Tromans for discussions which prompted the use of ADVs in this experimental campaign. We thank Harrif Santo of TCOMS for sharing his expertise from previous work. We are grateful to Guangwei Zhao and the technicians at Kelvin Hydrodynamics Laboratory for their assistance and expertise. A.J. Archer is supported by a Forrest Scholarship, Australia provided by the Forrest Research Foundation. H.A. Wolgamot is supported by an Australian Research Council, Australia (ARC) Early Career Fellowship ( DE200101478 ). H.A. Wolgamot and J. Orszaghova acknowledge the Australian Research Council Linkage Project LP210100397, the Research Impact Grant from the University of Western Australia, Australia , and the Blue Economy Cooperative Research Centre, Australia CRC-20180101 , established and supported under the Australian Government’s Cooperative Research Centres Program . The authors acknowledge support from the ARC ITRH for Transforming energy Infrastructure through Digital Engineering, Australia (TIDE, http://TIDE.edu.au) which is led by The University of Western Australia, delivered with The University of Wollongong and several other Australian and International research partners, and funded by the Australian Research Council, Australia, INPEX Operations Australia, Shell Australia, Woodside Energy, Australia, Fugro Australia Marine, Australia, Wood Group Kenny Australia, RPS Group, Australia, Bureau Veritas, Australia and Lloyd's Register Global Technology, Australia (Grant No. IH200100009). The authors are grateful to Mike Efthymiou and Peter Tromans for discussions which prompted the use of ADVs in this experimental campaign. We thank Harrif Santo of TCOMS for sharing his expertise from previous work. We are grateful to Guangwei Zhao and the technicians at Kelvin Hydrodynamics Laboratory for their assistance and expertise. A.J. Archer is supported by a Forrest Scholarship, Australia provided by the Forrest Research Foundation. H.A. Wolgamot is supported by an Australian Research Council, Australia (ARC) Early Career Fellowship (DE200101478). H.A. Wolgamot and J. Orszaghova acknowledge the Australian Research Council Linkage Project LP210100397, the Research Impact Grant from the University of Western Australia, Australia, and the Blue Economy Cooperative Research Centre, Australia CRC-20180101, established and supported under the Australian Government's Cooperative Research Centres Program.

Keywords

acoustic doppler velocimeter
actuator disc theory
blockage
offshore wind energy
wave–structure interactions

Access to Document

10.1016/j.jfluidstructs.2024.104076Licence: CC BY 4.0

Archer-etal-JFS-2024-ADV-measurements-of-blockage-flow-effectsFinal published version, 2.17 MBLicence: CC BY 4.0

Hydrodynamic testing of a jacket platform under wave and current loading
Dai, D. (Principal Investigator), Black, S. (Co-investigator), Yuan, Z. (Co-investigator) & Zhao, G. (Co-investigator)
University of Western Australia
3/04/23 → 9/10/23
Project: Knowledge Exchange (Services/Consultancy)

Kelvin Hydrodynamics Laboratory
Dai, D. (Manager)
Naval Architecture, Ocean And Marine Engineering
Facility/equipment: Facility

Cite this

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title = "ADV measurements of blockage flow effects near a model jacket in waves and current",

abstract = "Design standards for drag loading on offshore jacket structures do not presently account for the reduction in forces arising from flow blockage effects in the event of combined waves and current. This force reduction is believed to originate in reduced mean flow velocity through the jacket, but this has never been directly measured. To address this, we conducted physical-model tests which measured the flow adjacent to a jacket structure in combined waves and in-line currents using acoustic Doppler velocimeters. Results confirm a dramatic reduction in the mean flow velocity up-wave and down-wave of a model jacket in waves and current, far greater than the flow reduction observed in current alone. These results unambiguously confirm the significant additional blockage (and hence reduction in structural loads) not captured in current offshore design standards.",

keywords = "acoustic doppler velocimeter, actuator disc theory, blockage, offshore wind energy, wave–structure interactions",

author = "A.J. Archer and H.A. Wolgamot and J. Orszaghova and S. Dai and P.H. Taylor",

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T1 - ADV measurements of blockage flow effects near a model jacket in waves and current

AU - Archer, A.J.

AU - Wolgamot, H.A.

AU - Orszaghova, J.

AU - Dai, S.

AU - Taylor, P.H.

PY - 2024/3/31

Y1 - 2024/3/31

N2 - Design standards for drag loading on offshore jacket structures do not presently account for the reduction in forces arising from flow blockage effects in the event of combined waves and current. This force reduction is believed to originate in reduced mean flow velocity through the jacket, but this has never been directly measured. To address this, we conducted physical-model tests which measured the flow adjacent to a jacket structure in combined waves and in-line currents using acoustic Doppler velocimeters. Results confirm a dramatic reduction in the mean flow velocity up-wave and down-wave of a model jacket in waves and current, far greater than the flow reduction observed in current alone. These results unambiguously confirm the significant additional blockage (and hence reduction in structural loads) not captured in current offshore design standards.

AB - Design standards for drag loading on offshore jacket structures do not presently account for the reduction in forces arising from flow blockage effects in the event of combined waves and current. This force reduction is believed to originate in reduced mean flow velocity through the jacket, but this has never been directly measured. To address this, we conducted physical-model tests which measured the flow adjacent to a jacket structure in combined waves and in-line currents using acoustic Doppler velocimeters. Results confirm a dramatic reduction in the mean flow velocity up-wave and down-wave of a model jacket in waves and current, far greater than the flow reduction observed in current alone. These results unambiguously confirm the significant additional blockage (and hence reduction in structural loads) not captured in current offshore design standards.

KW - acoustic doppler velocimeter

KW - actuator disc theory

KW - blockage

KW - offshore wind energy

KW - wave–structure interactions

U2 - 10.1016/j.jfluidstructs.2024.104076

DO - 10.1016/j.jfluidstructs.2024.104076

M3 - Article

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JO - Journal of Fluids and Structures

JF - Journal of Fluids and Structures

M1 - 104076

ER -

ADV measurements of blockage flow effects near a model jacket in waves and current

Abstract

Funding

Keywords

Access to Document

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Projects

Hydrodynamic testing of a jacket platform under wave and current loading

Equipment

Kelvin Hydrodynamics Laboratory

Cite this