Proceedings of the Thirty-second (2022) International Ocean and Polar Engineering Conference
Shanghai, China, June 5–10, 2022
Copyright © 2022 by the International Society of Offshore and Polar Engineers (ISOPE)
ISBN 978-1-880653-81-4; ISSN 1098-6189

www.isope.org

Numerical Predication and Experimental Validation of Wind Load on a Jack-up Platform
Baili Zhang1, My Ha Dao1, Xiuqing Xing1, Jing Lou1
Wei Siang Tan2, Yongdong Cui2, Boo Cheong Khoo2
1Institute of High Performance Computing, Agency for Science, Technology and Research, Singapore
2Department of Mechanical Engineering, National University of Singapore, Singapore

ABSTRACTWhile significant effort has been made in numerical study ofaerodynamic loading on offshore platforms in the past two decades, theoffshore industry has begun using CFD as an alternative tool to predict
wind load on offshore structures including Jack-ups, semi-submersibles
and FPSOs (Jiang et al, 2013; Koop et al, 2010, 2012; Kim et al, 2018;
Yeon et al, 2021; Liu et al, 2021; Zhang et al, 2021). As the oil fields
continue to deplete, jack-up fleets are pushed towards deeper waters andharsher environments, more accurate and reliable wind load data are
required from computational tools. The CFD data-based Reduced Order
Methods (ROMs) enables investigation of wider range of scenarios andobtain the performance evaluations almost instantly (Xing et al, 2021,2022).

In a complex offshore environment, wind load is among the mostimportant design factors for the jack-up platform. In this study, we haveconducted a detailed numerical analysis of wind loading on a jack-up
platform in normal operation and extreme conditions at both model scale
and full scale for wind headings from 0 to 360 degrees. The wind load in
the form of coefficients of three force components and three momentcomponents are in good agreement between numerical prediction andexperimental measurements. In addition, we measured surface pressuresat 22 different locations of the platform, and they match well with CFD
calculations.

KEYWORDS: Wind Load; Jack-up; CFD simulation; wind tunnel

In this study, we have conducted detailed numerical analysis and windtunnel measurement of wind load on a jack-up platform in normal
operational condition and extreme condition at the model scale of 1:200
and at the wind speed of 20 m/s, for all wind headings from 0 to 360
degrees with a step of 10 degrees. The wind loads in the form ofcoefficients of three force components and three moment components
are in good agreement between numerical prediction and experimental
measurements. In addition, we measured surface pressures at 22 different
locations of the platform, and the calculated pressures from CFD
simulation matches well with wind tunnel test data.

test; wind velocity profile

INTRODUCTION
Being one of the typical types of Mobile Offshore Drilling Unit(MODU), the jack-up units are widely used in shallow to medium-deepwater (i.e. up to 170 meters deep) all over the world. In such complex
offshore operation environment, a jack-up platform is subject to both
aerodynamic and hydrodynamic loads from wind, wave and current.
Wind load is among the most important design load for the jack-up
structure, especially due to much larger projected area above water thanunder water. Therefore, it is critical to meet design requirement of thewind load with respect to the safety, reliability and stability of jack-up
platform in operation.

For the full-scale model, the CFD simulations are performed at different
design wind speeds, and the results justified the fully turbulent flow
assumption and the scalability of wind loads at the model scale. The
impact of wind profile shape is addressed in this paper as well.
The CFD simulation results produced in this study constitute a good
database to develop and validate CFD data-based Reduced Order
Methods, which is part of our efforts to build digital twins for wind load
predictions on marine vessels and offshore platforms.

Traditionally, the wind load acting on offshore structures is measured inwind tunnel tests, but with rapid development in Computational Fluid
Dynamics (CFD) and ever-increasing computing power, it is possible tosimulate wind flow around the offshore structure and calculate windloads numerically. However, good practice has to be followed in order
to benchmark CFD modelling with wind tunnel test result well.

712