Viscous damping effect and vortex shedding performance of the novel anti-motion structures on a cylindrical FPSO

Ji, Xinjie; Li, Yan; Tang, Yougang; Tong, Bo

doi:10.1016/j.oceaneng.2019.106430

Cited by 9 publications

(4 citation statements)

References 26 publications

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“…We validated the damping performances of the anti-motion structures in previous publications [9,20]. However, in those works, due to the limitations of the CFD-based model in Fluent, only free-decay tests and force-oscillation tests were finished, and the viscous damping term and the vortex shedding performance were only discussed.…”

Section: Resultsmentioning

confidence: 95%

“…Another possible solution to improve hydrodynamic performance is to design newtype floating structures. There are different kinds of non-ship-type FPSOs proposed, such as cylindrical bodies [8,9], multicylinder bodies [10], sandglass-type bodies [11,12], deep-draft multicolumn bodies [13,14], fillet inverted quadrangular frustum pyramid bodies [15,16], and so on. According to both numerical and experimental tests, their robust hydrodynamic performance is shown, especially the feature of insensitivity to the incident wave direction.…”

Section: Introductionmentioning

confidence: 99%

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Dynamic Responses of the Cylindrical Floating Drilling Production Storage and Offloading System with Annular Anti-Motion Structures under the Survival Sea Scenario

Zhao

et al. 2023

JMSE

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At present, dry wellheads are usually adopted on small-storage TLP and SPAR platforms to develop offshore oil and gas because of the robust hydrodynamic performance under severe-wind seas. On the other hand, FPSO and FDPSO platforms that have a larger storage capacity can hardly use this cost-saving facility due to their relatively poor vertical motion performance. Cylindrical FPSOs are proposed to improve the heave performance of ship-type FPSOs, but their behaviors are still too large to adopt the dry wellheads. In the present work, a cylindrical FDPSO platform is proposed based on the FWPSO platform, adding an extension cylinder and a new damping structure at the bottom. Their hydrodynamic performances are calculated by the potential theory and compared in the frequency domain. Taking two particular mooring systems, including both catenary and ‘chain-polyester-chain’ types, and the survival sea scenario in the South China Sea into account, a time-domain coupling analysis was adopted to simulate the dynamic performance of the platform-mooring system. The feasibility of dry wellhead adoption on the FDPSO is discussed by investigating the platform motion and the mooring tension. The results show that the FCDS platform with the ‘chain-polyester-chain’-type mooring system can meet the motion response requirements, and the mooring system can also meet the requirements of the specification.

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Section: Resultsmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 99%

Dynamic Responses of the Cylindrical Floating Drilling Production Storage and Offloading System with Annular Anti-Motion Structures under the Survival Sea Scenario

Zhao

et al. 2023

JMSE

Self Cite

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“…As shown in Figure 4, based on the wave spectrum of the selected location, the wave bands are in range of 3 to 12.5 sec and the peak of maximum wave spectrum is 8 s (0.08 Hz). The proposed FDP concept should be out of the wave band range to avoid large dynamic responses [31].…”

Section: (2)mentioning

confidence: 99%

Experimental investigation on the motion response of a novel floating desalination plant for Egypt

et al. 2020

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Increasing water demand in remote coastal areas in Egypt has shifted attention to the role of floating desalination plants to alleviate water shortages. A novel mobile floating desalination plant is proposed for Ras Ghareb city in Egypt. The compatibility between floater natural periods and the energy excitation range of waves in deployment area can lead to resonance responses. Therefore, understanding the motions behaviour among waves of such floaters at a particular location is important for its safety, performance and operation. The goal of the present study is to investigate the suitability of proposed concept for Egyptian environment conditions by characterising the behaviour of the plant motion responses during its entire deployment conditions. Based on full scale design of the proposed plant, experimental study over a range of wave heights and frequencies was performed in the present study using a 1:100 scale model test. In order to identify the plant natural frequency and damping ratio, free decay and swinging tests were performed for different load conditions. Different wave heights were tested during the experiments in order to investigate the effect of wave height on the heave and pitch responses at plant natural frequencies. The experimental test results were compared with numerical results from frequency domain program HydroD implemented in Sesam DNV GL software package. Results show that heave and pitch motion responses give the closest agreement between the measurements and numerical predictions over the whole range of wave periods except the peak spike. The proposed cylindrical FDP is compared against a conventional ship FPSO concept widely used for offshore freshwater production and it was concluded that new cylindrical FDP shows better motion responses compared to conventional ship FPSO concept in same wave bands in Egypt.

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“…With the model test methods, Ma analyzes its hydrodynamic characteristics under the irregular waves and rogue waves action and studies the motion response of FPSO and influence factors of the mooring force [10]. In order to reduce the hydrodynamic response of cylindrical FPSO, Ji et al construct the numerical model of cylindrical FPSO with various taper of anti-motion structure based on fluid dynamics computational method, obtain the damping coefficient through the model calculation, and then propose a new type of cone angle vibration resistant structure [11]. In order to quantify the coupling effects between each component in an offshore floating system and the associated structural response in offshore structure design, Afriana, Rika have presented two kind of analyses, the decoupled analysis and the nonlinear-coupled dynamic analysis in his Master thesis [12].…”

Section: Introductionmentioning

confidence: 99%

Study on Offloading Operation of Cylindrical FPSO Under Extreme Weather

Geng¹,

Lü²,

Wang³

et al. 2021

AJTTE

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With the wide application of cylindrical FPSO (Floating Production Storage and Offloading, FPSO), more and more people pay attention to its operational safety. To study and explore the safety of cylindrical FPSO offloading operation under extreme weather, it is necessary to conduct the simulation of whole operation process in such conditions. At first, the programming models are formulated for the cylindrical FPSO, shuttle tanker and tugs; then, based on the modelling, the responses of the cylindrical FPSO are simulated during offloading operation under various conditions, combined with Delphin Method and relevant theory. The most unfavorable load state and ultimate wind speed on unfavorable wind direction are explored through three stages: 1. changing the loading status of shuttle tanker and cylindrical FPSO; 2. changing the relative bearing of wind; 3. changing the wind speed. The results showed that when the offloading state is FPSO half-load & tanker half-load, it is the worst state to control the offloading system and the limit wind speed in the simulation is: cross wind ≤20 knots.By analyzing the motion response of cylindrical FPSO which is assisted by two tugs, a relatively objective and reasonable solution is obtained, which provides a beneficial reference for the future cylindrical FPSO offloading operation under the extreme weather conditions.

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Viscous damping effect and vortex shedding performance of the novel anti-motion structures on a cylindrical FPSO

Cited by 9 publications

References 26 publications

Dynamic Responses of the Cylindrical Floating Drilling Production Storage and Offloading System with Annular Anti-Motion Structures under the Survival Sea Scenario

Dynamic Responses of the Cylindrical Floating Drilling Production Storage and Offloading System with Annular Anti-Motion Structures under the Survival Sea Scenario

Experimental investigation on the motion response of a novel floating desalination plant for Egypt

Study on Offloading Operation of Cylindrical FPSO Under Extreme Weather

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