A review of ocean forces interaction modelwith offshore structures near the freesurfaceCite as: AIP Conference Proceedings 2157, 020038 (2019); https://doi.org/10.1063/1.5126573
Published Online: 18 September 2019
Zafarullah Nizamani, Akihiko Nakayama, Yusuke Uchiyama, and Tey Kim Hai

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AIP Conference Proceedings 2157, 020038 (2019); https://doi.org/10.1063/1.5126573© 2019 Author(s).

2157, 020038

A review of ocean forces interaction model with offshore
structures near the free surface
Zafarullah Nizamani1*, Akihiko Nakayama1, Yusuke Uchiyama 2, Tey Kim Hai3
1

Department of Environmental Engineering, Universiti Tunku Abdul Rahman, Malaysia
2
Department of Civil Engineering, KOBE University, Japan3
Department of Construction Management, Universiti Tunku Abdul Rahman, Malaysia*Email: zafarullah@utar.edu.my

Abstract. The importance is given for the efficient design of offshore structures which should include economic and safetyconcerns. The properties of wind-generated (main) surface waves and currents are recognized to play a vital role during designof offshore structures such as windmills, fixed and floating structures. This study looks into the mechanisms of metocean forces,
acting on these structures near the continental shelf region of Malaysia. At present, near offshore Malaysia, there is no real
behaviour model available for currents and the interaction between waves and current. The free surface flow and rigid bodyinteraction with structural issues of offshore structures such as fatigue, corrosion, and marine growth are also not researched inthis region before. Therefore, current and wave-current models need to be developed using the finite volume method. Physics
of these forces need to be determined and their free surface flow motions require the development of a framework. Fluidstructure interaction (FSI) is used to model the interfaces such as air-fluid (free surface) and fluid-structure (rigid-body). A Freesurface/rigid body problem fully coupled finite volume model is a preferred method. Six degree of freedom of motion equations
are used to define the rigid body. This paper is based on literature review and the expected results due to the effects of wind on
wave and currents and the mechanics of current are highlighted along with the seasonal effects of the current. To deal with themoving rigid body and the fluid domain interface an interface-tracking method is used.

INTRODUCTION
Oil and gas are one of the main items of revenue generation of the Malaysian economy. Offshore structures are
considered to be the backbone of the global renewable and conventional energy in future such as for PETRONAS
and Shell. Renewable wind energy is the key focus of the UNO and the Malaysian government such as the offshore
windmill. The local oil and gas industry is dealing with various types of offshore structures such as floatingproduction, storage and offloading offshore structures (FPSO), semi-submersibles i.e., SPAR, Tension leg
platforms, fixed Jacket platforms. Reduced oil prices in 2015-17, have hampered the development of new structuresdue to the high design and construction costs. In 2016, the prices of oil had reached between US Dollars 35-45 perbarrel. Thus to maintain upstream growth and development of new structures have become a challenge for the oiland gas development sector. Malaysian revenue from oil and gas decreased in the first quarter of 2016 by 26% ascompared to the same period in 2015 [1-2]. The design of structures is normally based on estimated load andresistance and thus if estimated loads are higher, the higher resistance is required. This will make the structure
economically expensive and unviable which has forced many projects to be shelved or postponed. The maincommon reason for uneconomical structures is the unavailability of robust real-time data on the behaviourof metocean parameters. The interaction of hydrodynamic forces and surface wave and current also plays asignificant role in corrosion and fatigue. The behaviour of current, which changes during the monsoons, is verysignificant in the design of structures. Different computer software is available such as SACS, SESAME, but they
are based mainly on engineering models using potential-flow theory and Morison's equation and they have inbuilt
libraries for codes such as API, ISO, DNV. They are used to evaluate hydrodynamic loads on these structures.
Computational fluid dynamics using fluid-structure interaction is proving to be extremely useful whenexperimental methods are expensive. While these models are computationally expensive, they include many
assumptions and approximations [3] and they depend on the behaviour of wind, wave and current model.
Unfortunately, these models are still not available for the offshore Malaysian region, especially the role of current
in Peninsular Malaysia, Sabah and Sarawak. Thus, it is high time to develop a high- reliability computational fluid
dynamics model. Understanding the fundamental current hydrodynamic forces in the offshore environment is
crucial to the success of future offshore projects. Current velocity mechanism near free surface close to offshore
structures is unidirectional at all heights. Based on the previous research it is clear that this behaviour is not thesame throughout the year. The metocean parameters interaction near the structures is not unidirectional as claimedby the simple design approach for these structures.

International Symposium on Green and Sustainable Technology (ISGST2019)
AIP Conf. Proc. 2157, 020038-1–020038-8; https://doi.org/10.1063/1.5126573
Published by AIP Publishing. 978-0-7354-1902-5/$30.00

020038-1

The cause of fatigue, corrosion and marine growth is related to the effects of metocean mechanism but at present,
no one knows the actual behaviour. Previous studies have been conducted on the weather in the North Sea and the
Gulf of Mexico. The weather pattern is completely different in the South China Sea. Turbulent flow mixing
of metocean parameters and their pressure forces near offshore structures cannot be taken simply by applying the
maximum values from each direction. The boundary layer of structure and metocean needs to be understood byusing Fluid-structure interaction. This paper will assist in the preparation of ISO 19901 and 19902 codes and inparticular an annexe for the wave and current loads. The requirement to compliment this annexe through an
extensive survey of wave and current forces estimation procedures have been recognized by the ISO code and thispaper makes an effort to meet these requirements. The paper contains more detailed references to the literature forthe hydrodynamic data needed in offshore design in Malaysia.

BACKGROUND OF STUDY
Malaysia a step towards development
In 2014 crude oil, condensates and gas contributed up to 20% of country’s gross domestic product (GDP) and it
was reported that since its incorporation PETRONAS has contributed RM 881 billion to the government andmajority of these came from offshore regions of Malaysia [2]. It is reported that only 50% of oil and gas resources
have been discovered and around 7.0 billion barrel of oil equivalent (BOE) in Malaysia and the rest is expected tocome from deepwater offshore areas Malaysia [2]. Thus, there are unlimited benefits for the growth of offshore
deep-water structures in Malaysia. The Eleventh Malaysian Plan developed one of the thrust area focusing on‘Strategy E which is related to “encouraging sustainable energy use to support growth is related to offshore oil andgas sustainability”. One of the six strategic thrust areas “accelerating human capital development for an advanced
nation” reports oil and gas as one of the important areas to be addressed in the 11th Malaysian plan. It shows thatin Sabah reliability will be enhanced for the supply of gas pipeline. Further pipeline networks will be laid from
offshore fields to FT Labuan, Kota Kinabalu and Kimanis in Sabah. Multiple links will be established for theconnectivity of the platforms to provide alternative route options in the event of platform shutdowns. Alternative
options will be provided from the offshore platforms for the case of emergency platform shutdown. The new
pipeline will be placed by Sabah-Sarawak Gas to facilitate and improve the connectivity for FT Labuan [4].

Design of offshore structures
The wave, wind and current play a significant role in the design of offshore structures and we need to understandthe phenomena that take place during the combined forces on these structures [5]. Many previous studies haveshown compressible and incompressible flows, including the structural mechanics with 2D solids and thin shell
type of structures. In the industry, small scale model tests are generally fabricated for prediction of wave impacts
loads, to examine structural motions, responses and time-dependent behaviour. But small-scale prototypes andexperimental tests are time-consuming and costly this paves way for the finite element and finite volume methods[6]. Previous studies in this region have largely focused on the South China Sea as a whole but not specificallythe region where the oil and gas reserve is located and without considering the combined effects of wind, wave
and current acting near and surrounding the offshore structures [7-13]. Offshore substructures are developed tosupport structures against complex offshore surroundings.
Offshore structures are always underexposure of flow-induced vibrations, which reduce their durability
significantly. The forces produced by environmental loads cause fatigue, due to successive wave current, twomost important loads for offshore structures. The effects of turbulent surface waves, due to wind pressure, on
ocean currents play an important role in engineering design. This includes wave forces at the surface of the ocean
and its interaction with current profiles at sea level, sediment transport and littoral flow [14].

Wave load
The primary forces on offshore substructures are caused by waves and deformation of waves caused byinteractions with the current [15]. For slender structural jacket components, loads due to wave and its response
are calculated using Morison equation such as piles, risers of the jacket and its members, Jack up, offshore

020038-2

pipelines. This is due to the consideration that the incident wave kinematics does not vary considerably nearstructural members. Large structures with having a large span covering a significant portion of the wavelength,
the incident waves undergo considerable diffraction or scattering such as FPSO. The wave force evaluation should
also take into account this scattering. Thus flow separation is ignored and it can be considered for a complete
potential flow and thus a nonlinear issue. Generally, by assuming a small wave height it can be linearized.
Wave theories
Wave loads are determined based on factors such as water depth, structural dimensions and design wave factors
and wave theory. For the probabilistic descriptions of waves and its forces, a linear wave theory is assumed. This
theory is used for the deterministic design of wave forces on large structures. Nonlinear wave theory is used forsmall tubular members. For deep waters, d/L > 0.01, Stokes 5th-order nonlinear wave theory is used, here, L =wavelength.
Waves along with currents
Ocean waves and currents act at the same time on the structures than the wave loads are determined by using the
combined flow field. The wave with non-uniform currents interaction is a complex phenomenon. The uniform
current influence in the presence of wave is analysed by using a wave theory in a fixed reference frame is related
to the conditions in which still water wave and current are analysed together as shown by Eq. (1),ܿ ൌ ܿ௢ ൅ ܷ  ߙ

(1)

U = Current moving in the direction of wave direction ߙ
c = wave speed (in the presence of current)co = wave speed without current
The influences of current on wave height have been demonstrated by Longuet-Higgins and Stewart [16].
Currents
Current magnitudes include three components such as tidal current Ut. At the surface level, this part of the current
can be obtained from tide tables or by hindcast data using a mathematical model. The other one is called lowfrequency Uc this is obtained from accompanying with long-term circulation patterns. The last one is caused bywind at ocean surface i.e. drift Uw near free surface and is about 3% of the wind speed of 10 min mean measured
at 10 m height. The current velocity U(z) vertical distribution is shown by Eq. (2),(2)‫ ݖ‬൅ ݀௢‫ ݖ‬൅ ݀ ଵȀ଻ܷሺ‫ݖ‬ሻ ൌ  ሺܷ௧ ൅ ܷ௖ ሻ ൬൰ ൅  ܷ௪ ൬൰݀௢݀‫ = ݖ‬Sea water level vertical ordinate
݀௢ = the depth of the temperature gradient / 50 m, whichever is less
A major vertical gradient in ocean water can give rise to the internal waves due to the long period it can produce
an extra component of current. Large amplitude internal current surges can occur near the continental shelf due todensity stratification. Table 1 shows the variations of water depth in offshore Malaysia along with maximum andminimum currents in critical directions.

020038-3

Table 1: Ocean mud level Depths for three regions of Malaysia
Extreme design current at surface level (m/sec)

Ocean depth (m)RegionPMO
SBO
SKO

Minimum

Maximum

Minimum

Maximum

60.0
36.9
46.0

79.2
59.1
95.0

0.68
0.66
0.40

1.50
2.23
1.80

Platform
specific
1.47
0.94
1.2

Fluid-structure interaction (FSI)

Motions of fluid and solid are coupled such as when leaves flap in the wind, the beating of hearts, the vibrationof wings of the aeroplane, rocking motion of ships and under the sea, risers or pipes are acted upon by waves andcurrents. Fluid-Structure Interaction (FSI) can be seen everywhere in our daily life. Thus, we can say that it plays
a significant part in the design of modern-day offshore structures [17]. As practical problems become moredifficult and expensive to conduct therefore understanding the basic phenomenon by using finite volume method
and then conducting the practical will be more viable. FSI has to deal with load and structural issues which are
fundamentally non-linear and time-dependent. Thus the analytical approaches are difficult to use. The maindifficulty in real flows scale has been the accurate modelling of turbulence.
The contour of the offshore structure and its dynamic motion define the behaviour of flow near it. Fluid forces
acting on the offshore structure will cause its motion and deformation. Computational fluid dynamics model aredeveloped for flow-induced vibrations. It helps to predict and mitigate phenomenon such as flutter, sloshing,vortex induced vibration and added mass for ocean engineering. Fluid-structure interaction (FSI) is a robust,
efficient and capable to model accurately computational model, with geometrically complex configurations.
Differential equations of fluid and solid mechanics, coupled at the fluid-solid interface are used to define theboundary between fluid and structure. Fundamentals of computational fluid and solid mechanics are used for thecomputation of fluid-structure behaviour. This is a vital physical phenomenon for offshore structures i.e.,
semisubmersibles, wind platforms, risers, platforms and floating structures. It provides the solution to real-world
problems. Fluid only or offshore jacket only problem is called as a single phase mechanics problem. In thiscase, problem domain is defined by the governing differential equations and boundary domain is defined by theboundary conditions which could be in motion or not. In FSI, the differential equation and boundary conditionsof water and solid must be solved simultaneously. They should not overlay and the two systems are coupled near
the interface [17]. The material properties of the structure will define its movement. Thereafter the fluid willchange to adjust the movement of the structure. The differential equations and boundary conditions will define
the water motion. The non-moving and moving grids are the two important discrete methods. Here motion of thefluid is the third unknown which is a function of structural displacement. The discretization of the fluid-structureinterface needs accuracy, stability and dealing with the intricate geometry. The separate fluid and structure
discretization will result in creating a mesh at the interface. Despite this, it must be ensured that fluid and thestructure are coupled through kinematics and tractions such as matching discretisation at the interface of fluid andstructure. As the interface of fluid-structure becomes complex flexibility becomes important. Loosely coupled
and strongly coupled are the two important FSI classes. In the first one sequential solutions are carried out for
fluid and structural mechanics and mesh issues [18-33]. For each step, time displacement rate at the interface, theequations of the fluid mechanics and the velocity is solved using the boundary conditions of the structure. Thenthe structural mechanic's equations are solved with the updated fluid mechanics interface traction. Finally, themesh moving equations is solved with the structural displacement at the boundary of two interfaces. the staggered
approach is preferred as it is deemed efficient [17].

Large eddy simulation
The large eddy method (the separation of scales) is one of the methods to analyse FSI behaviour. Turbulence
scales are resolved directly which are larger than the filter width. The smaller scales are parameterised by aturbulence model of sub grid-scale (SGS) [34]. As the major part of the energy is in large eddies the most of the020038-4

turbulence energy is resolved by the eddy. Grid resolution defines the width of the filter which can range between
50 to 100 m and reduced to 0.5-2 m respectively. For incompressible Navier–Stokes flows coupled with tubular
members, detached eddy approach is used. Combined turbulence model using eddy method is used. The Reynolds
average Navier-Stokes equation is used for modelling at high Reynolds number flows near free oscillating tubular
members. Near-wall flow features are modelled using wake dynamics along with Navier-Stokes.
METHODOLOGY
The structural design will also need to consider some other factors also like nonlinear (steep) coexisting andbreaking waves, vortex shedding. Due to the oil field requirements, this may also include the interference effects
between neighbouring structures and innovative structural configurations. The wave and current may also affecttow out or installation and fatigue and for this, a motion response analysis may be required to be done. Mooring
analysis of a fixed and floating structure could be used by FSI methods along with the intact and damaged reliability
analyses may also be required [37].
Loads acting on offshore structures
Malaysia offshore structures are located in shallow and deep waters. Regional oceanic modelling system isnecessary for the high turbulent flows near offshore structures. The currents in this region change directions at
different depths and act on these structures in a complex way. At present during design, many assumptions are madeto simplify the design. This simplification results in an extreme increase in costs. The strong and persistent currents,
with changing directions and coupled with waves creates an extreme mechanics of force. If these forces are
combined with wind direction, the problem becomes more complex. Besides that, there is no existing model of freesurface waves and issues related to corrosion, fatigue and marine growth in this region. The physical explanationof the underlying mechanism for metocean forces is to be researched. This will involve the analysis of some of theclimate data available with NASA.
The resonant response of the offshore structures in extreme environmental conditions should be evaluated. As
compared to the design wave frequency, the natural frequency of vibrations of the offshore structure is generally
very high. The linear wave theory does not show dynamic amplification for analysing the wave load. The nonlinear
waves contain significant energy; near the natural frequency of the vibration with higher harmonics will produce
resonance and significant wave loads which will amplify the structural dynamic response. Eddy method has beenused since the early 1970s for research subjects on turbulent flows at large Reynolds numbers in the atmosphericboundary layer [34].
This research will include flow model around a circular cylinder of large diameter. Ocean hindcast data throughNASA website will be analysed for the current, wave and wind. Then, the parameters such as grid density and thetime step size are determined. The behaviour of current and surface waves for different waves and amplitudes will
be analysed. Similarly, the effects of wind on the structure will also be explored. Thereafter, the developed model
will be used to determine wave and current loads on a vertical face of the structure.
Wave forces

Wave forces on tubular structural components give rise to separation of flow. Wave forces on floating offshore
structures such as FPSO the incident waves are diffracted. The short-term changes in waves are considered for
operating conditions and they are counted during a sea state of a return period whereas the long term variation isdetermined for specific sea states such as hurricanes. The longwave are defined by sea states, (6 h duration), andcharacterized by wave spectrum, significant wave height its direction, the degree of directional spreading of the
waves and wave period (peak period). The metocean data is obtained from the offshore platform or hindcast using
wind data and the probability distribution is used to define the wave parameters. the short-term distribution ofindividual significant wave heights is considered to follow Rayleigh probability distribution. During a sea state
individual wave height is shown by the Eq. (3),‫ܪ‬௠ͳൌ  ඨ  ܰ‫ܪ‬௦ʹ‫ܪ‬௠ = largest individual wave height

020038-5(3)‫ܪ‬௦ = significant wave height
N= number of waves
ఛ

ு೘

்

ுೞ

N = , where ߬ = duration taken and ܶ = zero-crossing wave period.

ൌ it is in range of 1.8-2.0.

S(f) = wave spectrum (distribution of wave energy). The most common form of wave spectra is Pierson- Moscowitz
spectrum or Bretschneider spectrum can determine the wave frequency or period as shown in Eq. (4),ͳͷ‫ܪ‬௦ ଶͷ ݂ ିସ݁‫݌ݔ‬ቈെ൬ ൰ ቉
ͳ͸݂௢ ሺ݂Ȁ݂௢ ሻହͶ ݂௢‫ܪ‬௦ = significant wave height and ݂௢ = peak frequency of the spectrum‫ݏ‬ሺ݂ሻ ൌ(4)

Finite volume method
The spatial and time scale of flow is usually large. The spacing of grid points and time step are used to resolve
dissipation of scales by dividing flow region into cubes and its order is smaller in length for large-scale flow. A
fraction of turbulent fluctuation can be resolved to get the mean flow and turbulent stresses. The filtered flow of
this scale can represent the overall characteristics of simulated flow [30-33]. Finite volume method, with
Smagorinsky subgrid scale (SGS) model, will be applied to simulate the ocean flow. LES has the ability to resolve
fine structures in the turbulent wake of the spar. Velocity profiles in the shell cylinder wake, hydrodynamics values,
and pressure distribution on spar wall will be investigated at and around the free surface to give a better
understanding of the physics.
Risk assessment
For offshore structures, risk due to failures from fatigue, corrosion, and marine growth can be measured by lossof life, property and production, environmental pollution all these losses are directly related to the costs of the
project. These risks can be minimised by reducing the probability of accident occurrence and/or minimizing theconsequences of such accidents. In this study, it is to be investigated that if a wave and current influenced windfield will affect the offshore structural loads, fatigue, corrosion and marine growth. This will be made by the use ofcomputational fluid dynamic (CFD) and by introducing a moving wave coupled with a response of the structure.

EXPECTED OUTCOMES AND CONCLUSIONS
It is well known that the current force plays a significant role in the design of offshore structures and this study
will provide a real current model based on the most recent data. The interaction of surface waves and current forces
to be used for the design of offshore structures will also be determined. The models for current, wave-current andwind-wave will be the main outcome of this study. The development of this model will provide a tool for oil andgas engineers with the actual behaviour of wind, wave and current. Truly predictive fluid-structure interaction
method is in high demand for offshore industry is moving towards deeper waters in general and ship industry inparticular. The behaviour of free surface flow and its effect on fatigue, corrosion, and marine growth will have asignificant impact on existing and new offshore structures. Thus the effect of surface environmental forces on
Fatigue, corrosion and marine growth will also be determined.
Impacts on Economy

The accurate information current, wave and wind will make future structures economical. This will benefit theoil and gas industry of Malaysia for their offshore installations. It will be good for society and the nation for safeand economical structures. This study is expected to show a great potential of the planned approach for the analysis
and design of the structures subjected to flow-induced vibrations due to metocean parameters. Fig. 1 shows theoffshore Malaysia region.

020038-6

Figure 1. Offshore Malaysia [37]Offshore oil and gas sector acts as a backbone of the Malaysian economy. The design of the offshore structures
is very significant from the cost and environment point of view. This study will have significant impacts on theeconomic and safe design and their effects after construction. This study can provide guidance on Malaysian annexe
to ISO 19901 and 19902 codes. Current as a force plays a significant role in the design of offshore structures. The
movement and behaviour of current in offshore Malaysia during different seasons has never been modelledpreviously. This study will develop a model based on realistic oceanic current flows such as sheared currents withvariable temperature, density and direction at the free surface. The models for the wave-current interaction andwind, wave and current at free surface acting on the offshore structures will also be developed. This study will
determine the effects of wave, current and wind load on offshore structures and it will enhance our understandingof fatigue, corrosion and marine growth in this region.

ACKNOWLEDGEMENTS
This work was supported by the MOHE Fundamental Research Grant Scheme (FRGS) under research project
Grant No. FRGS/1/2018/TK01/UTAR/02/4.

REFERENCES
1.
2.

PETRONAS Interim Financial Report, first quarter (2016).
The Malaysian Oil and Gas Industry, Challenging times, but fundamentals intact www.pwc.com/my(2016).
3. I. Akkerman, Y. Bazilevs, D. J. Benson, M. W. Farthing and C. E. Kees, Free-Surface Flow and FluidObject Interaction Modeling With emphasis on Ship Hydrodynamics, Journal of Applied Mechanics(2012).
4. Eleventh Malaysia plan 2016-2020, Anchoring growth on people (2016).
5. A. M. Kamath, Calculation of Wave Forces on Structures using REEF3D, PhD thesis, Norwegian
University of Science and Technology, Norway (2012).
6. A. Olsson, and M. Tunlid, CFD simulation of wave-in-deck loads on offshore structures, Master of Science
Thesis, Department of Shipping and Marine Technology, Division of Marine Structures andHydrodynamics, Chalmers University of technology (2015).
7. F. Tangang, C. Xia, F. Qiao, L. Juneng, F. Shan, Seasonal circulations in the Malay Peninsula Easterncontinental shelf from a wave–tide–circulation coupled model, Ocean Dynamics 61, 1317–1328 (2011).
8. W. L. Dale, Wind and drift currents in the South China Sea. Malay J tropical Geogr 8:1–31 (1956).
9. J. Hu, H. Kawamura, H. Hong, Y. Qi, A review on the currents in the South China Sea: seasonal
circulation,
South China Sea warm current and Kuroshio intrusion. J
Oceanography 56:607– 624 (2000).
10. P. T. Shaw, S. Y. Chao, Surface circulation in the South China Sea. Deep Sea Res. 41, 1663– 1683 (1994).
11. H. Yang, Q. Liu, Z. Liu, D. Wang, X. Liu, A general circulation model study of the dynamics of the upper
ocean circulation of the South China Sea. J Geophys Res 107(7), 3085 (2002)
12. S. Chandrasekaran, Dynamic Analysis and Design of Offshore Structures, Springer publication (2015).
Arthur Pecher, Jens Peter Kofoed, Handbook of Ocean Wave Energy. Springer Open Publication (2017).
13. Y. Uchiyama, J. Williams, A. Shchepetkin, Wave–current interaction in an oceanic circulation model with

020038-7

a vortex-force formalism: Application to the surf zone, Ocean Modelling 34, 16–35 (2010).
14. S. Y. Kim, K. M. Kim, J. C. Park, G. M. Jeon, H. H. Chun, Numerical simulation of wave and current
interaction with a fixed offshore substructure. International Journal of Naval Architecture and Ocean
Engineering 8, 188-197 (2016).
15. Michaelis Aacson, Wave and current forces on fixed offshore structures. Canadian Journal of Civil
Engineering, 15(6): 937-947 (1988).
16. Bazilevs Yuri, Takizawa Kenji and Tezduyar Tayfun, Computational Fluid- Structure Interaction, Methods
and applications, Wiley Series in Computational Mechanics (2013).
17. M. A. Benitz, Simulating the hydrodynamics of offshore floating wind turbine platforms in a finite volume
framework, PhD Thesis, University of Massachusetts Amherst, USA (2016)
18. G.A. Zarruk, E. A. Cowen, T. R. Wu and P. L. F. Liu, Vortex shedding and evolution induced by a solitary
wave propagating over a submerged cylindrical structure, J. Fluids and Structures, 52, 181-198 (2015).
19. W. Z. Lim and R. Y. Xiao, Fluid-structure interaction analysis of gravity-based structure (GBS) offshore
platform with partitioned coupling method, J. Ocean Engineering, 114, 1-9 (2016).
20. A. R. Foroughi, W. Sleeman, and R. Scott, Offshore Disasters: Wave forces on offshore and coastal
structures due to Tsunamis. First International Conference on Disaster Management and Human Health
Risk: Reducing Risk, Improving Outcomes, WIT Transactions on The Built Environment, UK (2009).
21. P. Catalano, M. Wang, G. Iaccarino and P. Moin, Numerical simulation of the flow around a circularcylinder at high Reynolds numbers. International Journal of Heat and Fluid Flow, 24, 463-469 (2003).
22. M. C. Ong, T. Utnes, L. E. Holmedal, D. Myrhaug and B. Pettersen, Numerical simulation of flow arounda circular cylinder close to a flat seabed at high Reynolds numbers using a k–ε model. Coastal Engineering,
57, 931-947 (2010).
23. J. Johansson, M. P. Nielsen and L. O. Nielsen, Uniform flow around a circular cylinder in the subcriticalrange - using the self-induced angular moment method turbulence model. The 8th Asia-Pacific Conference
on Wind Engineering, India (2013).
24. F. Tremblay, M. Manhart and R. Friedrich, LES of Flow around a Circular Cylinder at a Subcritical
Reynolds Number with Cartesian Grids. In: FRIEDRICH, R. & RODI, W. (eds.) Advances in LES ofComplex Flows. Springer Netherlands (2002).
25. E. Achenbach, Distribution of local pressure and skin friction around a circular cylinder in cross-flow up
to Re=5x106. J. Fluid Mech., 34, 625-639 (1968)
26. S. Li, B. W. Karney and G. Liu, FSI research in pipeline systems – A review of the literature. Journal of
Fluids and Structures, 57, 277-297 (2015).
27. W. Lin, C. Lin, S. Hsieh, and S. Dey, Flow Characteristics around a Circular Cylinder Placed Horizontally
above a Plane Boundary. Journal of Engg. Mechanics, 135, 697-716 (2009).
28. U. Rizza, M M. Miglietta, A. M. Sempreviva, F. Grasso and M. E. Schiano, Large- eddy simulation of
an offshore Mediterranean area. Meteorological Applications, 21(4), 910–921 (2014),
29. M. C. Ong, T. Utnes, L. E. Holmedal, D. Myrhaug and B. Pettersen, Numerical simulation of flow arounda smooth circular cylinder at very high Reynolds numbers. Marine Structures, 22, 142-153 (2009).
30. P. M. Abrahamsen, M. C. Ong, B. Pettersen and D. Myrhaug, Large Eddy Simulations of flow around asmooth circular cylinder in a uniform current in the subcritical flow regime. Ocean Engineering, 77, 6173 (2014).
31. A. Kulyakhtin, O. Shipilova and M. Muskulus, Numerical simulation of droplet impingement and flow
around a cylinder using RANS and LES models. Journal of Fluids and Structures, 48, 280-294 (2014).
32. I. Rodríguez, O. Lehmkuhl, J. Chiva, R. Borrell and A. Oliva, On the flow past a circular cylinder fromcritical to supercritical Reynolds numbers: Wake topology and vortex shedding. International Journal of
Heat & Fluid Flow (2015).
33. B. Maronga, M. Gryschka, R. Heinze, F. Hoffmann, F. K. Sühring, K. Ketelsen, M. O. Letzel, M. Sühring,and S. Raasch, The Parallelized Large-Eddy Simulation Model (PALM) version 4.0 for atmospheric andoceanic flows: model formulation, recent developments, and future perspectives, J. Geoscientific Model
Development, 8, 2515-2551 (2015).
34. T. Heus, C. C.Heerwaarden, H. J. J. Jonker, P. A. Siebesma, S. Axelsen, K. V. Dries, O. Geoffroy, A. F.
Moene, D. Pino, S. R. Roode, and J. V. Arellano, Formulation of the Dutch Atmospheric Large-Eddy
Simulation (DALES) and overview of its applications, Geosci. Model Dev, 3, 415–444 (2010).
35. U. Schumann, Subgrid scale model for finite difference simulations of turbulent flows in plane channels
and annuli, J. Comput. Phys., 18, 376–404 (1975).
36. Q. Yiquan, Z. Zhizu and S. Ping, "Extreme Wind, Wave and Current in Deep Water of South China Sea,"
International Journal of Offshore and Polar Engineers, vol. 20 (1), pp. 18-23 (2010).
37. S. Chandrasekaran, Advanced Marine Structures. CRC Press, Taylor and Francis Group (2016).

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