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

Ice Load Analysis Method Based on CFD-DEM Coupling Method
Bihao Chen 1*, Kai Zheng 1, Fanchao Wang 1, Junxia Zhu 1
1Marine Design & Research Institute of China
Shanghai, China*Corresponding author
ice load and design new offshore structures to improve ice resistance,
which is also an important engineering demand at present.
The traditional research focuses on prototype observation and modelexperiment. However, both methods require high cost and time. In terms
of prototype observation, the monitoring data and information provided
by it are important, but the monitoring targets depend on themeasurement system and measurement technology. At present, themeasurement data that can be directly used for analysis and research arevery limited（Timco ,2006）. In the model experiment, due to the scaleeffect and non-simultaneous failure, the ice force calculated by theformula obtained from the model experiment is more than 10 times larger
than the actual ice force. Therefore, if we can reasonably abstract andsimplify the problem and apply numerical analysis to explain theformation mechanism of ice load（Timco , 2009）, predict, analyze andstudy ice load, it can greatly reduce the cost and has very important
engineering significance.
In recent years, numerical simulation technology has become an
important way to study ice load. At present, numerical simulation ismainly carried out by finite element method and discrete element method,
but this method needs further development.

ABSTRACTIn this paper, a numerical calculation method of coupling CFD(Computational Fluid Dynamics) and DEM (discrete element method) isproposed. Some technical issues are discussed, including theestablishment of numerical ice pools, calibration of the parameters of thesea ice discrete element model, adaptability analysis of structures inmarine environment in ice area, etc. Aiming at the problem of ice load in
ice area, this paper presents a numerical calculation method by coupling
CFD with DEM, establishes a real sea ice model and a numerical icepond, and studies the ice resistance of Sandglass-type FPSO by using
this method. This paper provides a numerical calculation method foradaptability analysis of structures in marine environment in ice area. The
numerical sea ice model provided in this paper can simulate the realmechanical properties of sea ice. Compared with the calculation ofcylindrical floating body, Sandglass-type FPSO can significantly reducethe ice load. This research on ice load in ice area has a good application
value.
KEY WORDS:Discrete element; Coupling calculation;
Computational Fluid Dynamics; Sandglass-type FPSONUMERICAL ANALYSIS METHOD BASED ON COUPLING
OF CFD AND DEM

INTRODUCTION
The Arctic region has a large number of resources, of which theunexplored oil resources account for 25% of the world's unexplored oilresources. At the same time, the Arctic channel can save about 40% of
the voyage than the commonly used channel bypassing the Suez Canaland Panama Canal in the south（Wang,2009） .However, ships andother offshore structures working in the ice area will face serious sea iceengineering problems. In January 2000, JZ20-2 oil and gas platform
JZ20-2 oil and gas platform is subjected to sea ice dynamic pressure.
Finally, due to the fact that the natural frequency of the structure wasclose to the fracture frequency of sea ice, the fatigue fracture failure ofoil and gas pipelines was caused, resulting in serious economic losses（Yue,2003）. Ohio, sailing in the ice area, came into contact withicebergs in 1994, resulting in damage not only to the ballast tank but also
to the bulbous bow. （Hill,2006）.
People's lack of understanding of ice load is the main reason for thedamage accidents of offshore structures in these ice areas. Therefore,
more in-depth research and exploration are needed to accurately predict

CFD-DEM Coupling Calculation Method
The marine environment in ice area is actually a system of sea ice, fluid
and structure solid coupling. For the coupling problem between fluid andsolid, SPH method is mainly used at present. Because it does not needgrid, this method avoids the calculation impact caused by large grid
deformation due to large changes in flow field. However, for large-scalewind wave flow field with small changes in flow field, the calculation
will be more difficult and the calculation efficiency will be reduced.
Therefore, CFD method is used to couple with sea ice in this paper. For
the coupling between solid and solid, as shown in Figuree.1, it is a realsea ice slice. It can be found that sea ice is mainly composed of ice crystal
particles. Considering the real composition of sea ice, the discreteelement method is decided in this paper. In conclusion, this paper uses
dem-cfd coupling to establish a numerical ice pool for research.

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