Journal of Marine Science and Engineering

Research

19 pages, 4826 KB

Open AccessArticle

Hydrodynamic Effects and Scour Protection of a Geotextile Mattress with a Floating Plate

by Yehui Zhu, Yanhong Li and Liquan Xie

J. Mar. Sci. Eng. 2025, 13(12), 2215; https://doi.org/10.3390/jmse13122215 - 21 Nov 2025

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In this study, the evolution of the flow field near a Geotextile Mattress with a Floating Plate (GMFP) are numerically investigated, with a specific focus on the influence of the Froude number and the dynamic response of the floating plate. Key findings identify [...] Read more.

In this study, the evolution of the flow field near a Geotextile Mattress with a Floating Plate (GMFP) are numerically investigated, with a specific focus on the influence of the Froude number and the dynamic response of the floating plate. Key findings identify a critical Froude number that separates two protection regimes. Below this critical flow condition, the bottom vortex and the protective zone remain stable. Above it, the vortex contracts upstream, and the protection efficacy becomes substantial but diminished due to the competing effects of vortex development and a reduction in plate obstruction height. The bed shear stress over a considerable distance leeward of the GMFP is significantly reduced compared to unprotected conditions. Due to the blockage of the GMFP, upstream backup and downstream drawdown were observed in the water surface over the GMFP. These results provide valuable insights for the design and application of GMFPs, particularly in optimizing structural parameters to enhance protection effectiveness under varying flow conditions. Full article

(This article belongs to the Special Issue Advanced Studies in Marine Structures)

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19 pages, 9197 KB

Open AccessArticle

Optimal Design of Single Point Moorings for a Weathervaning Floating Wind Twin-Turbine Platform in Real Bathymetries

by Magnus Daniel Kallinger, Hector del Pozo Gonzalez, José Luis Domínguez-García and Javier Fernandez-Quijano

J. Mar. Sci. Eng. 2025, 13(11), 2155; https://doi.org/10.3390/jmse13112155 - 14 Nov 2025

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Abstract

This article presents the design and optimization of the mooring system for a floating wind platform inspired by W2Power, which incorporates two wind turbines on a semi-submersible structure that weathervanes using a single-point mooring (SPM) system. Although several industrial concepts have adopted SPM [...] Read more.

This article presents the design and optimization of the mooring system for a floating wind platform inspired by W2Power, which incorporates two wind turbines on a semi-submersible structure that weathervanes using a single-point mooring (SPM) system. Although several industrial concepts have adopted SPM configurations, research on their performance remains limited. This work addresses that gap by developing and applying a set of optimization strategies for the mooring system of such a platform using OrcaFlex, with the objective of minimizing the capital expenditure while satisfying Ultimate Limit State (ULS) and Fatigue Limit State (FLS) cases. The methodology was tested across two distinct marine environments: the Atlantic (Gran Canaria, GC-1) and the Mediterranean (Catalonia, LEBA-1), both characterized by their irregular bathymetry. In Catalonia, the environmental conditions are almost omnidirectional, while the platform in Gran Canaria is exposed to highly unidirectional loads. The article presents the most cost-effective solution for single-point moorings with three, four, and five lines in each case. Results demonstrate the viability of SPM-based floating wind systems with twin-turbines under diverse site conditions. Full article

(This article belongs to the Special Issue Advanced Studies in Marine Structures)

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35 pages, 12596 KB

Open AccessArticle

Novel T–U-Shaped Barge Design and Dynamic Response Analysis for Float-Over Installation of Offshore Converter Platform

by Ping Li, Li Zhao, Mingjun Ouyang, Kai Ye, Rui Zhao, Meiyan Zou and Mingsheng Chen

J. Mar. Sci. Eng. 2025, 13(10), 2004; https://doi.org/10.3390/jmse13102004 - 19 Oct 2025

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Abstract

To address the current lack of specialized equipment for offshore wind platform installation and the unresolved challenges in deploying large offshore converter stations, this paper proposes a novel T–U-shaped barge for large offshore wind structures. First, a hydrodynamic model of the T–U-shaped barge [...] Read more.

To address the current lack of specialized equipment for offshore wind platform installation and the unresolved challenges in deploying large offshore converter stations, this paper proposes a novel T–U-shaped barge for large offshore wind structures. First, a hydrodynamic model of the T–U-shaped barge is constructed and analyzed in ANSYS-AQWA. The influence of resonance occurring in the gap at the U-shaped stern on the frequency-domain model of the T–U-shaped barge is investigated. Subsequently, two installation configurations are examined: loading at the bow and loading at the stern of the T–U-shaped barge. This study comprehensively considers key components of the float-over installation system, including leg mating units (LMUs), deck support units (DSUs), fenders, and mooring cables. The results show that, for both installation schemes, the dynamic load distribution on each LMU evolves as the load-transfer stage progresses, and the sensitivity to wave period varies across different load-transfer stages, even under the same operating condition. This study evaluates the performance of the proposed T–U-shaped barge in the float-over installation of large offshore converter stations, demonstrating that its distinctive configuration endows it with strong functionality and provides valuable references for optimizing offshore wind-structure installation methods, as well as for the design and manufacturing of installation equipment. Full article

(This article belongs to the Special Issue Advanced Studies in Marine Structures)

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15 pages, 3772 KB

Open AccessArticle

Coupled Vibration Response Analysis of Tension Leg Platform Tendon Under Irregular Ocean Wave Action

by Qiangqiang Wu, Yinguang Du, Xiaofeng Luo, Tao Sun and Heng Lin

J. Mar. Sci. Eng. 2025, 13(10), 1836; https://doi.org/10.3390/jmse13101836 - 23 Sep 2025

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Abstract

To analyze the dynamic response of tension leg platform (TLP) tendons under irregular ocean wave action, the governing equations of coupled vibration between the platform and tendon under irregular wave action are established based on Hamilton’s principle and the Kirchhoff hypothesis. Using the [...] Read more.

To analyze the dynamic response of tension leg platform (TLP) tendons under irregular ocean wave action, the governing equations of coupled vibration between the platform and tendon under irregular wave action are established based on Hamilton’s principle and the Kirchhoff hypothesis. Using the spectrum representation–random function method, the power spectral density function of the irregular wave load is derived, and the lateral wave forces at different tendon locations are calculated. The coupled lateral and axial responses of the tendon system are obtained through the fourth-order Runge–Kutta method. Considering the parametric vibrations of both the platform and tendon, the extreme lateral deflection of the tendon is employed as the control index to derive the probability density curves of the tendon deflection under irregular wave load. The results show that the amplitude of the wave load increases gradually along the height of the tendon, with a faster growth rate at locations closer to the water surface. The tendon’s lateral deflection response changes more drastically due to coupled parametric vibration of the platform. Based on 628 complete samples of irregular wave loads, the probability density curve and cumulative distribution curve of the extreme lateral deflection of the tendon under irregular wave loads are obtained. Under typical sea state conditions generated from the P-M wave spectrum, the reliability of the tendon under irregular wave load increases with the initial tension force. Full article

(This article belongs to the Special Issue Advanced Studies in Marine Structures)

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28 pages, 1790 KB

Open AccessArticle

Stabilization of Floating Offshore Wind Turbines with a Passive Stability-Enhancing Skirted Trapezoidal Platform

by Hanbyeol Kim, Hassan Saghi, Injae Jeon and Goangseup Zi

J. Mar. Sci. Eng. 2025, 13(9), 1658; https://doi.org/10.3390/jmse13091658 - 29 Aug 2025

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Abstract

In this study, an innovative passive stability-enhancing barge platform geometry is presented to improve the operational efficiency of floating offshore wind turbines (FOWTs) by mitigating platform motion caused by wave action. Barge-type FOWTs, which primarily rely on surface support, have received less attention [...] Read more.

In this study, an innovative passive stability-enhancing barge platform geometry is presented to improve the operational efficiency of floating offshore wind turbines (FOWTs) by mitigating platform motion caused by wave action. Barge-type FOWTs, which primarily rely on surface support, have received less attention in terms of geometric optimization. The proposed design incorporates skirts and a trapezoidal cross-sectional shape for the barge platforms.To achieve effective stability given cost-effect considerations, geometrical optimization was performed while maintaining the same mass as the original design. Positioning the skirt with a height-to-diameter ratio of 0.8 reduces platform movements considerably, decreasing the heave by approximately 20% and the pitch by up to 70% relative to the original design. In addition, the analysis demonstrated that increasing the moonpool area to approximately 400 m² (approximately 10% of the platform’s surface area) led to an additional reduction in the heave and pitch responses. A specific moonpool diameter saturation point value was identified to increase the stability of the floater. Finally, the platform configuration yielded consistently lower peak motions across different wave angles, demonstrating improved stability. Full article

(This article belongs to the Special Issue Advanced Studies in Marine Structures)

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20 pages, 4410 KB

Open AccessArticle

Experimental Investigation on the Hydraulic Characteristics of Self-Rotating Flood Barrier

by Jooyeon Lee, Byoungjoon Na and Sang-Ho Oh

J. Mar. Sci. Eng. 2025, 13(8), 1542; https://doi.org/10.3390/jmse13081542 - 11 Aug 2025

Viewed by 1516

Abstract

This study investigated the hydraulic characteristics of a self-rotating flood barrier (SRFB) by performing laboratory experiments. The SRFB is proposed as a secure solution to withstand both waves and sudden water level rise, thereby protecting the coastal area behind it. The SRFB is [...] Read more.

This study investigated the hydraulic characteristics of a self-rotating flood barrier (SRFB) by performing laboratory experiments. The SRFB is proposed as a secure solution to withstand both waves and sudden water level rise, thereby protecting the coastal area behind it. The SRFB is designed to rotate and rise automatically by buoyancy when the water level exceeds a certain threshold or waves start to overtop the crest level of the caisson, where the barrier is enclosed. The barrier begins to rise when the chamber is filled with enough water for the buoyancy force to exceed its own weight. The performance of the structure was tested under various regular wave conditions at different water depths. Pressure transducers were placed along the front face of the barrier to measure the wave pressures acting on it. The barrier’s angular displacement was also identified using synchronized video footage during the measurements. The results showed that the overall magnitude of the measured pressures increased with water depth due to the larger volume of water inflow from overtopping waves. During the rise in the barrier, the pressure profiles dynamically varied with the rotation angle as the pattern of water flow into the chamber changed depending on the test cases. Analysis results showed how the pressures are distributed along the barrier at the moment of peak wave force. These findings would provide fundamental information for estimating design wave forces on the structure. Full article

(This article belongs to the Special Issue Advanced Studies in Marine Structures)

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19 pages, 3316 KB

Open AccessArticle

Optimization Design of Dynamic Cable Configuration Considering Thermo-Mechanical Coupling Effects

by Ying Li, Guanggen Zou, Suchun Yang, Dongsheng Qiao and Bin Wang

J. Mar. Sci. Eng. 2025, 13(7), 1336; https://doi.org/10.3390/jmse13071336 - 13 Jul 2025

Viewed by 810

Abstract

During operation, dynamic cables endure coupled thermo-mechanical loads (mechanical: tension/bending; thermal: power transmission) that degrade stiffness, amplifying extreme responses and impairing configuration optimization. To address this, this study pioneers a multi-objective optimization framework integrating stiffness characteristics from mechanical/thermo-mechanical analyses, with objectives to minimize [...] Read more.

During operation, dynamic cables endure coupled thermo-mechanical loads (mechanical: tension/bending; thermal: power transmission) that degrade stiffness, amplifying extreme responses and impairing configuration optimization. To address this, this study pioneers a multi-objective optimization framework integrating stiffness characteristics from mechanical/thermo-mechanical analyses, with objectives to minimize dynamic extreme tension and curvature under constraints of global configuration variables and safety thresholds. The framework employs a Radial Basis Function (RBF) surrogate model coupled with NSGA-II algorithm, yielding validated Pareto solutions (≤6.15% max error vs. simulations). Results demonstrate universal reduction in extreme responses across optimized configurations, with the thermo-mechanically optimized solution achieving 20.24% fatigue life enhancement. This work establishes the first methodology quantifying thermo-mechanical coupling effects on offshore cable safety and fatigue performance. This configuration design scheme exhibits better safety during actual service conditions. Full article

(This article belongs to the Special Issue Advanced Studies in Marine Structures)

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15 pages, 6772 KB

Open AccessArticle

Dynamic Response Analysis of a Novel Tension-Leg Dual-Module Offshore Wind Turbine System During Both Installation and Removal Processes

by Shi Liu, Xinran Guo, Yi Yang, Hongxing Wang, Shenghua Wei, Nianxin Ren and Chaohe Chen

J. Mar. Sci. Eng. 2025, 13(5), 888; https://doi.org/10.3390/jmse13050888 - 29 Apr 2025

Cited by 1 | Viewed by 785

Abstract

To facilitate both the installation and the removal of floating offshore wind turbines (FOWTs), a novel tension-leg dual-module offshore wind turbine system has been proposed. This system primarily consists of a DTU 10 MW wind turbine (WT) module and a supporting tension-leg platform [...] Read more.

To facilitate both the installation and the removal of floating offshore wind turbines (FOWTs), a novel tension-leg dual-module offshore wind turbine system has been proposed. This system primarily consists of a DTU 10 MW wind turbine (WT) module and a supporting tension-leg platform (TLP) module. Considering both mechanical and hydrodynamic coupling effects of the dual-module system, this study focuses on its dynamic responses during both the installation and the removal of the WT module under typical sea states. The effect of different installation vessel positions and key parameters of the clamping device on the dynamic response of the system during the WT module removal has been clarified. Based on the findings, preliminary recommendations are provided regarding the optimal positioning of the installation vessel and the optimal design parameters of the clamping device. Furthermore, an auxiliary sleeve has been proposed to facilitate the WT module removal. The results indicate that the application of the auxiliary sleeve can significantly improve the dynamic response of the system. The results of this study can serve as a reference for the design, installation, and removal of floating offshore wind turbines. Full article

(This article belongs to the Special Issue Advanced Studies in Marine Structures)

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