Journal of Ocean Engineering and Science最新文献_第6页

Dynamics of optical pulses in birefringent fibers without four-wave mixing effect via efficient computational techniques 基于高效计算技术的无四波混频双折射光纤中光脉冲动力学

IF 13 1区工程技术 Q1 ENGINEERING, MARINE

Journal of Ocean Engineering and Science

Pub Date : 2025-04-01 DOI: 10.1016/j.joes.2022.06.036

Usman Younas , Hadi Rezazadeh , Jingli Ren

In this manuscript, we discuss the dynamical behavior of Chen-Lee-Liu (CLL) equation in birefringent fibers which is modeled by two-component nonlinear Schrodinger equation (NLSE) without four-wave mixing effect. In optical fibers and other wave-guide mediums this system models the propagation of soliton flow using group velocity dispersion (GVD) and self-steeping coefficients. In the realms of maritime transport, motion, and energy, the dynamics of deep-sea waves is one of oceanography’s greatest challenges. A mathematical model of the dynamics of solitary waves in the deep ocean under a two-layer stratification yields the NLSE, and resultantly, the interaction between the two can be described by a coupled NLSE. Using two recently developed integration tools, namely the generalized exponential rational function method (GERFM) and the new extended direct algebraic method (NEDAM), the various optical pulses in the forms of bright, dark, combined, and complex solitons are extracted. Moreover, the hyperbolic, exponential, and trigonometric function solutions are recovered. In addition, a comparison is made between our results and those that are well-known, and the study concludes that the solutions we’ve reached are novel. By choosing appropriate parameter values for numerical simulation and physical explanations, the significance of the results is demonstrated. The results of this paper can enhance the nonlinear dynamical behavior of a given system and demonstrate the suitability of the methodology employed. This research, in our opinion, will be beneficial to a wide variety of engineering model specialists.

本文讨论了用双分量非线性薛定谔方程（NLSE）模拟的双折射光纤中没有四波混频效应的Chen-Lee-Liu （CLL）方程的动力学行为。在光纤和其他波导介质中，该系统使用群速度色散（GVD）和自渗透系数来模拟孤子流的传播。在海洋运输、运动和能源领域，深海波浪的动力学是海洋学面临的最大挑战之一。在两层分层条件下，深海孤立波动力学的数学模型得到了最小二乘线线，因此，两者之间的相互作用可以用一个耦合的最小二乘线线线来描述。利用最近发展起来的两种积分工具，即广义指数有理函数法（GERFM）和新的扩展直接代数法（NEDAM），提取了亮孤子、暗孤子、组合孤子和复孤子形式的各种光脉冲。此外，还恢复了双曲、指数和三角函数的解。此外，我们的研究结果与那些众所周知的研究结果进行了比较，得出的结论是，我们得出的解决方案是新颖的。通过选择合适的参数值进行数值模拟和物理解释，论证了结果的意义。本文的结果可以增强给定系统的非线性动力学行为，并证明所采用方法的适用性。这项研究，在我们看来，将有利于各种各样的工程模型专家。

{"title":"Dynamics of optical pulses in birefringent fibers without four-wave mixing effect via efficient computational techniques","authors":"Usman Younas , Hadi Rezazadeh , Jingli Ren","doi":"10.1016/j.joes.2022.06.036","DOIUrl":"10.1016/j.joes.2022.06.036","url":null,"abstract":"<div><div>In this manuscript, we discuss the dynamical behavior of Chen-Lee-Liu (CLL) equation in birefringent fibers which is modeled by two-component nonlinear Schrodinger equation (NLSE) without four-wave mixing effect. In optical fibers and other wave-guide mediums this system models the propagation of soliton flow using group velocity dispersion (GVD) and self-steeping coefficients. In the realms of maritime transport, motion, and energy, the dynamics of deep-sea waves is one of oceanography’s greatest challenges. A mathematical model of the dynamics of solitary waves in the deep ocean under a two-layer stratification yields the NLSE, and resultantly, the interaction between the two can be described by a coupled NLSE. Using two recently developed integration tools, namely the generalized exponential rational function method (GERFM) and the new extended direct algebraic method (NEDAM), the various optical pulses in the forms of bright, dark, combined, and complex solitons are extracted. Moreover, the hyperbolic, exponential, and trigonometric function solutions are recovered. In addition, a comparison is made between our results and those that are well-known, and the study concludes that the solutions we’ve reached are novel. By choosing appropriate parameter values for numerical simulation and physical explanations, the significance of the results is demonstrated. The results of this paper can enhance the nonlinear dynamical behavior of a given system and demonstrate the suitability of the methodology employed. This research, in our opinion, will be beneficial to a wide variety of engineering model specialists.</div></div>","PeriodicalId":48514,"journal":{"name":"Journal of Ocean Engineering and Science","volume":"10 2","pages":"Pages 181-196"},"PeriodicalIF":13.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41413443","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Stereo vision-based measurement of wave evolution around square column in laboratory 基于立体视觉的实验室方柱周围波演化测量

IF 13 1区工程技术 Q1 ENGINEERING, MARINE

Journal of Ocean Engineering and Science

Pub Date : 2025-04-01 DOI: 10.1016/j.joes.2023.10.002

Deyu Li , Handi Wei , Longfei Xiao , Ruiwen Zhang , Yan Li

The spatial-temporal measurement of complex wave evolution is significant in studying wave-structure interactions. Current methods, such as that using wave probes, have shown limitations in measuring the wave evolution around structures in laboratories. In this study, an improved stereo imaging method is proposed for measuring the wave evolution around a fixed structure. Regular wave tests were conducted on a fixed surface-piercing square column in a wave flume to validate the reliability and accuracy of the proposed method. A flexible marker-net made of foam particles was arranged around the column to provide Lambertian features for the water surface. Two synchronized stereo imaging systems covered all the surrounding areas of the column and provided stereo pair sequences for wave evolution. Subsequently, image segmentation techniques were used to mask the low-confidence disparities in stereo matching, and finally, three-dimensional (3D) wave surfaces were reconstructed in the time sequence. The time histories of the wave elevations at particular locations were extracted and agreed well with the measurements of wave probes with an average bias of 2.4 %. Subsequently, the reconstructed 3D wave field was sliced, exhibiting the instantaneous profiles that agreed with the measurements of wave probes. Moreover, the wave run-up height ratios were consistent with those of a previous study, thereby verifying the method's accuracy from the perspective of spatial evolution. The results demonstrated that the proposed method was capable of precisely measuring the spatial-temporal evolution of the wave field around the square column and displayed potential for application in more studies on wave-structure interactions.

复波演化的时空测量对于研究波-结构相互作用具有重要意义。目前的方法，如使用波探针，在实验室测量结构周围的波演变方面显示出局限性。本文提出了一种改进的立体成像方法，用于测量固定结构周围的波演化。在波浪水槽中对固定穿面方柱进行了常规波浪试验，验证了该方法的可靠性和准确性。由泡沫颗粒制成的柔性标记网排列在柱子周围，为水面提供朗伯特征。两套同步立体成像系统覆盖了柱体周围的所有区域，为波浪演化提供了立体对序列。随后，利用图像分割技术掩盖立体匹配中的低置信度差异，最后按时间序列重建三维波面。提取了特定位置的波浪高程时程，与波浪探头测量结果吻合较好，平均偏差为2.4%。随后，对重建的三维波场进行切片，显示出与波探头测量结果一致的瞬时剖面。波浪爬高比与前人研究结果一致，从空间演化角度验证了方法的准确性。结果表明，该方法能够精确测量方柱周围波场的时空演变，在更多的波-结构相互作用研究中具有应用潜力。

{"title":"Stereo vision-based measurement of wave evolution around square column in laboratory","authors":"Deyu Li , Handi Wei , Longfei Xiao , Ruiwen Zhang , Yan Li","doi":"10.1016/j.joes.2023.10.002","DOIUrl":"10.1016/j.joes.2023.10.002","url":null,"abstract":"<div><div>The spatial-temporal measurement of complex wave evolution is significant in studying wave-structure interactions. Current methods, such as that using wave probes, have shown limitations in measuring the wave evolution around structures in laboratories. In this study, an improved stereo imaging method is proposed for measuring the wave evolution around a fixed structure. Regular wave tests were conducted on a fixed surface-piercing square column in a wave flume to validate the reliability and accuracy of the proposed method. A flexible marker-net made of foam particles was arranged around the column to provide Lambertian features for the water surface. Two synchronized stereo imaging systems covered all the surrounding areas of the column and provided stereo pair sequences for wave evolution. Subsequently, image segmentation techniques were used to mask the low-confidence disparities in stereo matching, and finally, three-dimensional (3D) wave surfaces were reconstructed in the time sequence. The time histories of the wave elevations at particular locations were extracted and agreed well with the measurements of wave probes with an average bias of 2.4 %. Subsequently, the reconstructed 3D wave field was sliced, exhibiting the instantaneous profiles that agreed with the measurements of wave probes. Moreover, the wave run-up height ratios were consistent with those of a previous study, thereby verifying the method's accuracy from the perspective of spatial evolution. The results demonstrated that the proposed method was capable of precisely measuring the spatial-temporal evolution of the wave field around the square column and displayed potential for application in more studies on wave-structure interactions.</div></div>","PeriodicalId":48514,"journal":{"name":"Journal of Ocean Engineering and Science","volume":"10 2","pages":"Pages 281-294"},"PeriodicalIF":13.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135708005","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

An investigation of the dynamic behaviour of two rigid cylinders in a tandem arrangement under vortex-induced vibration 涡激振动下两刚性圆柱串列结构的动力特性研究

IF 13 1区工程技术 Q1 ENGINEERING, MARINE

Journal of Ocean Engineering and Science

Pub Date : 2025-04-01 DOI: 10.1016/j.joes.2022.05.035

Noor Idora Mohd Sukarnoor , Lee Kee Quen , Aminudin Abu , Kang Hooi Siang , Noriyuki Kuwano , Safari Mat Desa

The flow interference of multiple cylinders subjected to vortex-induced vibration (VIV) is a complex response that is not fully understood. This paper investigates the fluid-dynamic behaviour of elastically mounted rigid cylinders where both cylinders were free to oscillate in the cross-flow direction. The cylinders were subjected to uniform water flow at various separation distances of 3.5, 4.0, and 4.5D (D is the diameter of the cylinder) in a tandem arrangement. Based on the observation, the interference between the cylinders and the unsteady wake from the leading cylinder caused a continuous vibration with no lower branch in amplitude response. While as found in the cases of the single cylinder, there was a lower branch in amplitude response. The results also revealed that the cylinders experienced the VIV and wake-induced vibration (WIV) at each separation distance. Moreover, the leading cylinder oscillated at a larger amplitude at a separation distance of 3.5D, indicating a critical distance for cylinders in the tandem arrangement due to the existence of a bistable regime. Hence, it is reasonable to conclude that the flow interference between the leading and trailing cylinders significantly impacts the cylinders’ dynamic behaviour.

多圆柱涡激振动（VIV）下的流动干涉是一个尚未完全理解的复杂响应。本文研究了弹性安装刚性圆柱体的流体动力学特性，其中两个圆柱体在横向流动方向上自由振荡。在3.5 D、4.0 D、4.5D （D为筒体直径）的不同分离距离上，柱体以串联方式承受均匀的水流。通过观察可知，圆柱与前导圆柱的非定常尾迹之间的干涉导致了振幅响应无下支的连续振动。而在单柱的情况下，振幅响应有一个较低的分支。结果还表明，在不同的分离距离下，柱体分别经历了涡激振动和尾迹诱发振动。此外，在3.5D的分离距离处，先导柱的振荡幅度更大，表明由于双稳区的存在，柱在串联布置中存在临界距离。因此，可以合理地得出结论，前后气缸之间的流动干涉对气缸的动力性能有显著影响。

{"title":"An investigation of the dynamic behaviour of two rigid cylinders in a tandem arrangement under vortex-induced vibration","authors":"Noor Idora Mohd Sukarnoor , Lee Kee Quen , Aminudin Abu , Kang Hooi Siang , Noriyuki Kuwano , Safari Mat Desa","doi":"10.1016/j.joes.2022.05.035","DOIUrl":"10.1016/j.joes.2022.05.035","url":null,"abstract":"<div><div>The flow interference of multiple cylinders subjected to vortex-induced vibration (VIV) is a complex response that is not fully understood. This paper investigates the fluid-dynamic behaviour of elastically mounted rigid cylinders where both cylinders were free to oscillate in the cross-flow direction. The cylinders were subjected to uniform water flow at various separation distances of 3.5, 4.0, and 4.5<em>D</em> (<em>D</em> is the diameter of the cylinder) in a tandem arrangement. Based on the observation, the interference between the cylinders and the unsteady wake from the leading cylinder caused a continuous vibration with no lower branch in amplitude response. While as found in the cases of the single cylinder, there was a lower branch in amplitude response. The results also revealed that the cylinders experienced the VIV and wake-induced vibration (WIV) at each separation distance. Moreover, the leading cylinder oscillated at a larger amplitude at a separation distance of 3.5<em>D</em>, indicating a critical distance for cylinders in the tandem arrangement due to the existence of a bistable regime. Hence, it is reasonable to conclude that the flow interference between the leading and trailing cylinders significantly impacts the cylinders’ dynamic behaviour.</div></div>","PeriodicalId":48514,"journal":{"name":"Journal of Ocean Engineering and Science","volume":"10 2","pages":"Pages 246-257"},"PeriodicalIF":13.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42906513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Mechanism analysis and prediction of longitudinal cut wave pattern resistance based on CFD simulation 基于CFD模拟的纵切波纹阻力机理分析与预测

IF 13 1区工程技术 Q1 ENGINEERING, MARINE

Journal of Ocean Engineering and Science

Pub Date : 2025-04-01 DOI: 10.1016/j.joes.2023.07.001

Xiaocong Wang, Renchuan Zhu, Dekang Xu, Hui Wang, Yue Gu

Inspired by ITTC 2021 (International Towing Tank Conference), this paper implements the Longitudinal Cut Method (LCM), a methodology to predict wave pattern resistance (R_wp), within Computational Fluid Dynamics (CFD) simulation to explore its mechanism and feasibility in predicting wave resistance (R_w). To accurately predict the free surface, a validation study, including the grid convergence index (GCI), wave profile, and wave pattern, is conducted for a Series 60 ship model. Next, R_wp is appropriately evaluated and compared with the experiment. The influence of the transverse wave component on the LCM analysis is also discussed. Furthermore, a comparison between the EFD (Experimental Fluid Dynamics) and CFD-based LCM is made through the analysis of the Wigley Catamaran, highlighting the advantages of the present approach. Finally, the limitations of the LCM theory are systematically discussed with the nonlinear bow wave analysis of a wall-sided ship model by introducing the local adaptive mesh refinement (LAMR) approach. For the fine hull form, LCM has been validated as a suitable methodology for directly predicting R_w and consequently the other primary resistance components (frictional resistance R_f and viscous pressure resistance R_pv) by one simulation. In contrast, due to energy dissipation of the non-negligible nonlinear local field wave component in the downstream wake region, R_w could be underestimated for the full hull form.

受ITTC 2021（国际拖曳舱会议）的启发，本文在计算流体动力学（CFD）模拟中实现了纵向切割法（LCM），这是一种预测波型阻力（Rwp）的方法，以探索其预测波型阻力（Rw）的机制和可行性。为了准确地预测自由面，对60系列船舶模型进行了网格收敛指数（GCI）、波浪剖面和波浪型的验证研究。接下来，对Rwp进行适当的评估，并与实验进行比较。讨论了横波分量对LCM分析的影响。此外，通过对Wigley双体船的分析，比较了实验流体动力学（EFD）和基于cfd的LCM，突出了该方法的优势。最后，通过引入局部自适应网格细化（LAMR）方法，系统地讨论了LCM理论的局限性。对于细船型，LCM已通过一次模拟验证为直接预测Rw以及其他主要阻力分量（摩擦阻力Rf和粘性压力阻力Rpv）的合适方法。相反，由于下游尾迹区不可忽略的非线性局部场波分量的能量耗散，对于全船型，Rw可能被低估。

{"title":"Mechanism analysis and prediction of longitudinal cut wave pattern resistance based on CFD simulation","authors":"Xiaocong Wang, Renchuan Zhu, Dekang Xu, Hui Wang, Yue Gu","doi":"10.1016/j.joes.2023.07.001","DOIUrl":"10.1016/j.joes.2023.07.001","url":null,"abstract":"<div><div>Inspired by ITTC 2021 (International Towing Tank Conference), this paper implements the Longitudinal Cut Method (LCM), a methodology to predict wave pattern resistance (<em>R<sub>wp</sub></em>), within Computational Fluid Dynamics (CFD) simulation to explore its mechanism and feasibility in predicting wave resistance (<em>R<sub>w</sub></em>). To accurately predict the free surface, a validation study, including the grid convergence index (<em>GCI</em>), wave profile, and wave pattern, is conducted for a Series 60 ship model. Next, <em>R<sub>wp</sub></em> is appropriately evaluated and compared with the experiment. The influence of the transverse wave component on the LCM analysis is also discussed. Furthermore, a comparison between the EFD (Experimental Fluid Dynamics) and CFD-based LCM is made through the analysis of the Wigley Catamaran, highlighting the advantages of the present approach. Finally, the limitations of the LCM theory are systematically discussed with the nonlinear bow wave analysis of a wall-sided ship model by introducing the local adaptive mesh refinement (LAMR) approach. For the fine hull form, LCM has been validated as a suitable methodology for directly predicting <em>R<sub>w</sub></em> and consequently the other primary resistance components (frictional resistance <em>R<sub>f</sub></em> and viscous pressure resistance <em>R<sub>pv</sub></em>) by one simulation. In contrast, due to energy dissipation of the non-negligible nonlinear local field wave component in the downstream wake region, <em>R<sub>w</sub></em> could be underestimated for the full hull form.</div></div>","PeriodicalId":48514,"journal":{"name":"Journal of Ocean Engineering and Science","volume":"10 2","pages":"Pages 258-273"},"PeriodicalIF":13.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48516165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A novel multi-module coupled algorithm for the wreck off-bottom simulation 沉船离底仿真的一种新型多模块耦合算法

IF 13 1区工程技术 Q1 ENGINEERING, MARINE

Journal of Ocean Engineering and Science

Pub Date : 2025-04-01 DOI: 10.1016/j.joes.2023.05.003

Shangzhe Xin , Yiting Wang , Lei Wang , Xiaodong Zhu , Shihai Chen , Dongrong Zhou

This paper proposes a novel multi-module coupled algorithm for the wreck off-bottom simulation (MCAWOS), involving several structures, multiple mediums, and three modules: the wreck-soil interaction module, the lifting-buffering module, and the barge-cable coupled module. In the present algorithm, the finite element method, the potential flow method and the lumped mass method are integrated and used to simulate the off-bottom process. The dynamic response characteristics of a typical salvage case with rated lifting tensions are investigated. It is found that the salvage system in waves exhibits a special breakout phenomenon, where the wreck displacements increase abruptly, and uneven distributions of the lifting tensions are observed. Case studies are conducted to further ascertain the mechanism of the breakout. As the rated lifting tension increases, the salvage efficiency rises, while the maximum roll and pitch amplitudes of the wreck decrease. Meanwhile, larger rated tension may result in more waste in equipment lifting capacity, thus 229 ton is finally selected as the appropriate preset lifting tension. In addition, when the wave direction angle increases from 90

^{\circ}

to 180

^{\circ}

, the maximum roll value of the wreck shows a roughly decreasing trend and the planar deflection of the salvage barge relative to the wreck decreases. However, the maximum values of pitch, yaw, lifting tension and Mises seabed soil stress show irregular fluctuations. Taking all dynamic indicators into account, the wave heading interval of 150

^{\circ}

to 180

^{\circ}

is expected to be an ideal operating window. Conversely the 105

^{\circ}

case is a dangerous state.

本文提出了一种新的沉船离底仿真多模块耦合算法，该算法涉及多种结构、多种介质和三个模块：沉船-土壤相互作用模块、提升-缓冲模块和驳船-缆索耦合模块。该算法将有限元法、势流法和集总质量法相结合，用于模拟离底过程。研究了典型打捞箱在额定升降张力下的动态响应特性。研究发现，在波浪作用下，打捞系统表现出一种特殊的突围现象，沉船位移急剧增大，吊张力分布不均匀。个案研究，以进一步确定爆发的机制。随着额定起升张力的增大，打捞效率提高，而沉船最大横摇幅值和俯仰幅值减小。同时，较大的额定张力可能会造成设备提升能力的浪费，因此最终选择229吨作为合适的预置提升张力。此外，当波浪方向角从90°增加到180°时，沉船的最大横摇值大致呈减小趋势，打捞驳船相对于沉船的平面偏转减小。而俯仰、偏航、提升张力和Mises海床土应力的最大值呈不规则波动。考虑到所有的动态指标，150到180度的波浪朝向间隔预计是一个理想的操作窗口。相反，105°的情况是危险的。

{"title":"A novel multi-module coupled algorithm for the wreck off-bottom simulation","authors":"Shangzhe Xin , Yiting Wang , Lei Wang , Xiaodong Zhu , Shihai Chen , Dongrong Zhou","doi":"10.1016/j.joes.2023.05.003","DOIUrl":"10.1016/j.joes.2023.05.003","url":null,"abstract":"<div><div>This paper proposes a novel multi-module coupled algorithm for the wreck off-bottom simulation (MCAWOS), involving several structures, multiple mediums, and three modules: the wreck-soil interaction module, the lifting-buffering module, and the barge-cable coupled module. In the present algorithm, the finite element method, the potential flow method and the lumped mass method are integrated and used to simulate the off-bottom process. The dynamic response characteristics of a typical salvage case with rated lifting tensions are investigated. It is found that the salvage system in waves exhibits a special breakout phenomenon, where the wreck displacements increase abruptly, and uneven distributions of the lifting tensions are observed. Case studies are conducted to further ascertain the mechanism of the breakout. As the rated lifting tension increases, the salvage efficiency rises, while the maximum roll and pitch amplitudes of the wreck decrease. Meanwhile, larger rated tension may result in more waste in equipment lifting capacity, thus 229 ton is finally selected as the appropriate preset lifting tension. In addition, when the wave direction angle increases from 90<span><math><msup><mrow></mrow><mo>∘</mo></msup></math></span> to 180<span><math><msup><mrow></mrow><mo>∘</mo></msup></math></span>, the maximum roll value of the wreck shows a roughly decreasing trend and the planar deflection of the salvage barge relative to the wreck decreases. However, the maximum values of pitch, yaw, lifting tension and Mises seabed soil stress show irregular fluctuations. Taking all dynamic indicators into account, the wave heading interval of 150<span><math><msup><mrow></mrow><mo>∘</mo></msup></math></span> to 180<span><math><msup><mrow></mrow><mo>∘</mo></msup></math></span> is expected to be an ideal operating window. Conversely the 105<span><math><msup><mrow></mrow><mo>∘</mo></msup></math></span> case is a dangerous state.</div></div>","PeriodicalId":48514,"journal":{"name":"Journal of Ocean Engineering and Science","volume":"10 2","pages":"Pages 197-212"},"PeriodicalIF":13.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135821211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Backscattering enhancements by partially exposed cylindrical shells due to reflected flexural waves at air–water interfaces 由于空气-水界面处的反射弯曲波，部分暴露的圆柱壳增强了后向散射

IF 13 1区工程技术 Q1 ENGINEERING, MARINE

Journal of Ocean Engineering and Science

Pub Date : 2025-04-01 DOI: 10.1016/j.joes.2023.07.006

Liwen Tan , Jun Fan , Bin Wang , Kaiqi Zhao , Bing Li

For smooth curved objects in contact with a flat interface, the propagation paths of supported surface elastic waves can be altered by the interface, thereby enhancing the characteristics of the backscattered echo returns. In this study, backscattering experiments are conducted on an empty stainless steel cylindrical shell that breaks through an air–water interface and is insonified from below at grazing incidence. The shell has a thickness-to-radius ratio of 5%. The frequencies of interest fall within the vicinity of and below the coincidence frequency, which corresponds to a ka range of 13.8–20.1. The experimental results demonstrate that, for the partially exposed cylindrical shell, the flexural waves can traverse the interface and circumnavigate the shell multiple times. The flexural waves experience mode transitions upon passing through the interface, existing as a₀₋ waves below the interface and a₀ waves above the interface. Simultaneously, the flexural waves undergo partial reflection each time they pass through the interface, guiding them to follow a reverse path and generating a periodic series of echo returns, which leads to the enhancement of backscattering. The shift in resonance frequency in relation to the changing exposure is analyzed and predicted using the phase matching theory.

对于与平面界面接触的光滑曲面物体，受支撑的表面弹性波的传播路径可以被界面改变，从而增强了后向散射回波的特性。在这项研究中，在一个空的不锈钢圆柱壳上进行了后向散射实验，该壳穿过空气-水界面，在掠入射下从下面进行失谐。壳体的厚度-半径比为5%。感兴趣的频率落在重合频率附近或以下，对应于13.8-20.1的ka范围。实验结果表明，对于部分暴露的圆柱壳，弯曲波可以多次穿过界面并绕壳飞行。挠曲波通过界面后经历模态转变，在界面下方以a0−波存在，在界面上方以a0波存在。同时，弯曲波每次通过界面时都会发生部分反射，引导它们沿着相反的路径，并产生周期性的一系列回波，从而导致后向散射增强。利用相位匹配理论分析和预测了谐振频率随曝光量变化的变化。

{"title":"Backscattering enhancements by partially exposed cylindrical shells due to reflected flexural waves at air–water interfaces","authors":"Liwen Tan , Jun Fan , Bin Wang , Kaiqi Zhao , Bing Li","doi":"10.1016/j.joes.2023.07.006","DOIUrl":"10.1016/j.joes.2023.07.006","url":null,"abstract":"<div><div>For smooth curved objects in contact with a flat interface, the propagation paths of supported surface elastic waves can be altered by the interface, thereby enhancing the characteristics of the backscattered echo returns. In this study, backscattering experiments are conducted on an empty stainless steel cylindrical shell that breaks through an air–water interface and is insonified from below at grazing incidence. The shell has a thickness-to-radius ratio of 5%. The frequencies of interest fall within the vicinity of and below the coincidence frequency, which corresponds to a <em>ka</em> range of 13.8–20.1. The experimental results demonstrate that, for the partially exposed cylindrical shell, the flexural waves can traverse the interface and circumnavigate the shell multiple times. The flexural waves experience mode transitions upon passing through the interface, existing as <em>a</em><sub>0−</sub> waves below the interface and <em>a</em><sub>0</sub> waves above the interface. Simultaneously, the flexural waves undergo partial reflection each time they pass through the interface, guiding them to follow a reverse path and generating a periodic series of echo returns, which leads to the enhancement of backscattering. The shift in resonance frequency in relation to the changing exposure is analyzed and predicted using the phase matching theory.</div></div>","PeriodicalId":48514,"journal":{"name":"Journal of Ocean Engineering and Science","volume":"10 2","pages":"Pages 274-280"},"PeriodicalIF":13.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41950798","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Predicting motions of deepwater platform based on the inverse reconstruction of environmental loads 基于环境载荷逆重构的深水平台运动预测

IF 13 1区工程技术 Q1 ENGINEERING, MARINE

Journal of Ocean Engineering and Science

Pub Date : 2025-04-01 DOI: 10.1016/j.joes.2023.06.003

Xu Li , Handi Wei , Longfei Xiao , Ziyang Zhu , Yufeng Kou , Mingyue Liu

In hybrid model testing technique, model tests are primarily used to verify numerical models which is used to predict the responses of full-depth systems. However, hybrid model testing method based on potential flow theory highly rely on the accuracy of mathematical model, facing challenges in accurately predicting full-depth responses with viscous effects, such as flow-induced motion. To solve the problem, a method for predicting motions of full-depth system is proposed based on the inverse reconstruction of the environmental loads from the truncated model test, considering viscous and nonlinear effects on platform. To validate the method, a series of model tests were conducted for a semi-submersible platform in head seas using both truncated and full-depth mooring systems to validate the method. The environmental loads could be extracted accurately via the inverse reconstruction method under different environmental conditions, including 100-year-return-period wave-only, current-only, coupled wave, wind, and current conditions. The results of time history, statistics, and power distribution show that the proposed method has better performance than conventional method of hybrid model test in situations where viscous effects are obvious.

在混合模型试验技术中，模型试验主要用于验证用于预测全深度系统响应的数值模型。然而，基于势流理论的混合模型测试方法高度依赖数学模型的准确性，难以准确预测流致运动等粘滞效应下的全深响应。为解决这一问题，提出了一种基于截尾模型试验环境荷载逆重构的全深系统运动预测方法，同时考虑了平台上的粘性和非线性效应。为了验证该方法，在首海的半潜式平台上进行了一系列模型试验，使用截断和全深度系泊系统来验证该方法。通过逆重建方法可以准确提取不同环境条件下的环境荷载，包括百年周期纯波、纯流、耦合波、风和流条件。时间历史、统计和功率分布结果表明，在粘性效应明显的情况下，该方法比传统的混合模型试验方法具有更好的性能。

{"title":"Predicting motions of deepwater platform based on the inverse reconstruction of environmental loads","authors":"Xu Li , Handi Wei , Longfei Xiao , Ziyang Zhu , Yufeng Kou , Mingyue Liu","doi":"10.1016/j.joes.2023.06.003","DOIUrl":"10.1016/j.joes.2023.06.003","url":null,"abstract":"<div><div>In hybrid model testing technique, model tests are primarily used to verify numerical models which is used to predict the responses of full-depth systems. However, hybrid model testing method based on potential flow theory highly rely on the accuracy of mathematical model, facing challenges in accurately predicting full-depth responses with viscous effects, such as flow-induced motion. To solve the problem, a method for predicting motions of full-depth system is proposed based on the inverse reconstruction of the environmental loads from the truncated model test, considering viscous and nonlinear effects on platform. To validate the method, a series of model tests were conducted for a semi-submersible platform in head seas using both truncated and full-depth mooring systems to validate the method. The environmental loads could be extracted accurately via the inverse reconstruction method under different environmental conditions, including 100-year-return-period wave-only, current-only, coupled wave, wind, and current conditions. The results of time history, statistics, and power distribution show that the proposed method has better performance than conventional method of hybrid model test in situations where viscous effects are obvious.</div></div>","PeriodicalId":48514,"journal":{"name":"Journal of Ocean Engineering and Science","volume":"10 2","pages":"Pages 213-228"},"PeriodicalIF":13.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48425636","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Variance-tuned ensemble Gaussian process regression for learning and prediction of ship maneuvering motion 船舶操纵运动学习与预测的方差调谐系综高斯过程回归

IF 11.8 1区工程技术 Q1 ENGINEERING, MARINE

Journal of Ocean Engineering and Science

Pub Date : 2025-03-28 DOI: 10.1016/j.joes.2025.03.001

Zi-Lu Ouyang , Yi-Fan Xue , Zao-Jian Zou , Gang Chen

With the development of maritime transportation, ship maneuverability is attracting increasing attention, the learning and modeling of ship maneuvering motion is the basis of studying the ship maneuverability. Machine learning methods such as Gaussian process regression (GPR) are widely employed in the learning and prediction of ship dynamics. However, the predictions by the learning model always exhibit distinct deviations when the ship motion to be predicted are quite different from those of the training dataset. To deal with this problem, a robust method based on variance-tuned ensemble GPR learning method is proposed. Multiple base predictors are trained based on GPR each from a different bootstrap dataset. The weight values of each base predictor are adaptive with variance-tuned strategy during the whole prediction process. Taking the ONR Tumblehome ship and KRISO Very Large Crude Oil Carrier 2 tanker as study objects, the results indicate that the proposed method exhibits strong generalization capabilities and achieves high accuracy in predictions.

随着海上运输的发展，船舶操纵性越来越受到人们的重视，船舶操纵性运动的学习和建模是研究船舶操纵性的基础。机器学习方法如高斯过程回归（GPR）被广泛应用于船舶动力学的学习和预测。然而，当待预测的船舶运动与训练数据集的预测差异很大时，学习模型的预测结果往往会出现明显的偏差。为了解决这一问题，提出了一种基于方差调谐集成GPR学习方法的鲁棒方法。基于GPR训练了多个基础预测器，每个预测器来自不同的bootstrap数据集。在整个预测过程中，各基预测器的权重值采用方差调优策略自适应。以ONR Tumblehome船和KRISO超大型原油运输船2号为研究对象，结果表明，该方法具有较强的泛化能力，预测精度较高。

{"title":"Variance-tuned ensemble Gaussian process regression for learning and prediction of ship maneuvering motion","authors":"Zi-Lu Ouyang , Yi-Fan Xue , Zao-Jian Zou , Gang Chen","doi":"10.1016/j.joes.2025.03.001","DOIUrl":"10.1016/j.joes.2025.03.001","url":null,"abstract":"<div><div>With the development of maritime transportation, ship maneuverability is attracting increasing attention, the learning and modeling of ship maneuvering motion is the basis of studying the ship maneuverability. Machine learning methods such as Gaussian process regression (GPR) are widely employed in the learning and prediction of ship dynamics. However, the predictions by the learning model always exhibit distinct deviations when the ship motion to be predicted are quite different from those of the training dataset. To deal with this problem, a robust method based on variance-tuned ensemble GPR learning method is proposed. Multiple base predictors are trained based on GPR each from a different bootstrap dataset. The weight values of each base predictor are adaptive with variance-tuned strategy during the whole prediction process. Taking the ONR Tumblehome ship and KRISO Very Large Crude Oil Carrier 2 tanker as study objects, the results indicate that the proposed method exhibits strong generalization capabilities and achieves high accuracy in predictions.</div></div>","PeriodicalId":48514,"journal":{"name":"Journal of Ocean Engineering and Science","volume":"10 5","pages":"Pages 851-863"},"PeriodicalIF":11.8,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145046730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Experimental study on dynamic response of deep-draft cylindrical offshore platform under wave loads 波浪荷载作用下深吃水圆柱形海洋平台动力响应试验研究

IF 11.8 1区工程技术 Q1 ENGINEERING, MARINE

Journal of Ocean Engineering and Science

Pub Date : 2025-02-25 DOI: 10.1016/j.joes.2025.02.002

Chengming Qin , Zhe Chen , Yanping He , Zi Wang , Min Zeng , Chenze Cao

The offshore nuclear power platform is a remote island power supply with great prospects for development. This paper addresses the hydrodynamic performance of a new deep-draft cylindrical offshore platform for carrying nuclear reactors. The platform solves the problems of motion resonance and space waste of arranging the nuclear reactor directly on the traditional cylindrical platform and SPAR platform. The novelty of the platform is highlighted through statistical generalization based on dimensionless master scale parameters. A test model and scheme suitable for deep-draft cylindrical offshore platform are established. Through the model test, the platform natural properties and the motion response under different sea conditions are obtained. Spectral analysis is applied to study the platform motion and mooring tension response characteristics. The results show that the natural motion periods of the platform are obviously larger than the main wave period range of the operating sea area, and the resonance risk is low. Under the sea state of 1-in-100-years, the maximum displacement of the platform is 14.088 m, and the maximum dynamic inclination is 10.223°. The motion performance meets the design requirements. It is worth noting that the pitch plays a significant effect in influencing the heave, yaw, and mooring line tension response. This effect is greater as the sea state roughness increases. Improving the pitch of the platform deserves in-depth study. In addition, the results of this study address the gap in experimental data, providing a reference for numerical modeling and further research.

海上核电平台是一种极具发展前景的偏远海岛供电方式。本文研究了一种新型深吃水圆柱形核反应堆海上运载平台的水动力性能。该平台解决了传统圆柱平台和SPAR平台直接布置核反应堆的运动共振和空间浪费问题。通过基于无量纲主尺度参数的统计泛化，突出了平台的新颖性。建立了适用于深吃水圆柱形海洋平台的试验模型和试验方案。通过模型试验，得到了平台在不同海况下的自然特性和运动响应。采用谱分析方法研究了平台运动和系泊张力响应特性。结果表明：平台的自然运动周期明显大于作业海域的主波周期范围，共振风险较低；在百年一遇的海况下，平台最大位移为14.088 m，最大动力倾角为10.223°。运动性能满足设计要求。值得注意的是，纵摇对船舶的升沉、偏航和系缆张力响应有显著影响。这种影响随着海况粗糙度的增加而增大。提高平台的音高值得深入研究。此外，本研究的结果弥补了实验数据的空白，为数值模拟和进一步研究提供了参考。

{"title":"Experimental study on dynamic response of deep-draft cylindrical offshore platform under wave loads","authors":"Chengming Qin , Zhe Chen , Yanping He , Zi Wang , Min Zeng , Chenze Cao","doi":"10.1016/j.joes.2025.02.002","DOIUrl":"10.1016/j.joes.2025.02.002","url":null,"abstract":"<div><div>The offshore nuclear power platform is a remote island power supply with great prospects for development. This paper addresses the hydrodynamic performance of a new deep-draft cylindrical offshore platform for carrying nuclear reactors. The platform solves the problems of motion resonance and space waste of arranging the nuclear reactor directly on the traditional cylindrical platform and SPAR platform. The novelty of the platform is highlighted through statistical generalization based on dimensionless master scale parameters. A test model and scheme suitable for deep-draft cylindrical offshore platform are established. Through the model test, the platform natural properties and the motion response under different sea conditions are obtained. Spectral analysis is applied to study the platform motion and mooring tension response characteristics. The results show that the natural motion periods of the platform are obviously larger than the main wave period range of the operating sea area, and the resonance risk is low. Under the sea state of 1-in-100-years, the maximum displacement of the platform is 14.088 m, and the maximum dynamic inclination is 10.223°. The motion performance meets the design requirements. It is worth noting that the pitch plays a significant effect in influencing the heave, yaw, and mooring line tension response. This effect is greater as the sea state roughness increases. Improving the pitch of the platform deserves in-depth study. In addition, the results of this study address the gap in experimental data, providing a reference for numerical modeling and further research.</div></div>","PeriodicalId":48514,"journal":{"name":"Journal of Ocean Engineering and Science","volume":"10 5","pages":"Pages 830-850"},"PeriodicalIF":11.8,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145050467","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Enhanced intelligent reconstruction study on wind wave height field in the South China Sea 南海风浪高场增强智能重建研究

IF 11.8 1区工程技术 Q1 ENGINEERING, MARINE

Journal of Ocean Engineering and Science

Pub Date : 2025-02-17 DOI: 10.1016/j.joes.2025.02.001

Chenglin Li , Hang Xu , Xiaochen Feng , Qiang Sun

This paper addresses the challenge of scarcity and discontinuity in spatio-temporal observation data within oceanographic research. The primary goal is to develop a robust model capable of generating missing wave height data and enhancing the understanding of ocean wave behavior. We propose an end-to-end spatio-temporal sequence generation network based on convolutional U-Net, utilizing reanalyzed atmospheric datasets from the European Centre for Medium-Range Weather Forecasts (ECMWF). The model incorporates input features such as wind wave height, wave direction, mean wave period, and wind speed to generate significant wind wave heights in the South China Sea at specified times. Data smoothing was applied at intervals of 12, 24, and 36 h under both moderate and extreme wave conditions, resulting in wave height data at 6-hour intervals. The findings demonstrate that the model effectively captures areas with high wave heights, outperforming traditional interpolation-based methods, especially as input data time intervals increase and wave conditions intensify. This approach offers a novel solution for generating missing spatio-temporal data, providing valuable insights into ocean wave behavior and supporting applications in ocean engineering.

本文解决了海洋研究中时空观测数据的稀缺性和不连续性的挑战。主要目标是开发一个强大的模型，能够生成缺失的波高数据，并增强对海浪行为的理解。我们提出了一个基于卷积U-Net的端到端时空序列生成网络，利用欧洲中期天气预报中心（ECMWF）重新分析的大气数据集。该模式结合风浪高度、波浪方向、平均波周期和风速等输入特征，在特定时间生成南海显著的风浪高度。在中等和极端波浪条件下，每隔12、24和36小时对数据进行平滑处理，得到每隔6小时的波高数据。研究结果表明，该模型有效地捕获了高波高区域，优于传统的基于插值的方法，特别是当输入数据时间间隔增加和波浪条件加剧时。该方法为生成缺失的时空数据提供了一种新颖的解决方案，为海浪行为提供了有价值的见解，并支持海洋工程中的应用。

{"title":"Enhanced intelligent reconstruction study on wind wave height field in the South China Sea","authors":"Chenglin Li , Hang Xu , Xiaochen Feng , Qiang Sun","doi":"10.1016/j.joes.2025.02.001","DOIUrl":"10.1016/j.joes.2025.02.001","url":null,"abstract":"<div><div>This paper addresses the challenge of scarcity and discontinuity in spatio-temporal observation data within oceanographic research. The primary goal is to develop a robust model capable of generating missing wave height data and enhancing the understanding of ocean wave behavior. We propose an end-to-end spatio-temporal sequence generation network based on convolutional U-Net, utilizing reanalyzed atmospheric datasets from the European Centre for Medium-Range Weather Forecasts (ECMWF). The model incorporates input features such as wind wave height, wave direction, mean wave period, and wind speed to generate significant wind wave heights in the South China Sea at specified times. Data smoothing was applied at intervals of 12, 24, and 36 h under both moderate and extreme wave conditions, resulting in wave height data at 6-hour intervals. The findings demonstrate that the model effectively captures areas with high wave heights, outperforming traditional interpolation-based methods, especially as input data time intervals increase and wave conditions intensify. This approach offers a novel solution for generating missing spatio-temporal data, providing valuable insights into ocean wave behavior and supporting applications in ocean engineering.</div></div>","PeriodicalId":48514,"journal":{"name":"Journal of Ocean Engineering and Science","volume":"10 6","pages":"Pages 897-915"},"PeriodicalIF":11.8,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145469117","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0