Applied Ocean Research最新文献_第3页

Event-triggered model-free adaptive sliding-mode heading control for unmanned surface vehicles under DoS attacks DoS 攻击下无人水面飞行器的事件触发无模型自适应滑模航向控制

IF 4.3 2区工程技术

Applied Ocean Research Pub Date : 2024-09-04 DOI: 10.1016/j.apor.2024.104203

引用次数: 0

Shaking table test of TLD/TLCD vibration control for offshore wind turbine support structure 用于海上风力涡轮机支撑结构的 TLD/TLCD 振动控制振动台试验

IF 4.3 2区工程技术

Applied Ocean Research Pub Date : 2024-09-04 DOI: 10.1016/j.apor.2024.104207

{"title":"Shaking table test of TLD/TLCD vibration control for offshore wind turbine support structure","authors":"","doi":"10.1016/j.apor.2024.104207","DOIUrl":"10.1016/j.apor.2024.104207","url":null,"abstract":"<div><p>In this research, a scale-model with a similarity-ratio of 1:15 is specifically designed for shaking table test based on a 6.45MW OWT (Offshore wind turbine). The scale-model is equipped with a TLD (Tuned liquid damper) at the top and a TLCD (Tuned liquid column damper) at 2/3 of its height. Various external excitations with distinct spectral characteristics are applied to analyze the vibration characteristics of the OWT and the damping performance of the TLD/TLCD. The results indicate that the dynamic characteristics satisfy the similarity-ratio between the prototype-model and scale-model. The acceleration response of the OWT is significantly influenced by the external excitation spectrum, whereas the displacement response is primarily governed by the model 1<sup>st</sup>-order natural-frequency. With the mass eccentricity applied at the tower top and bidirectional excitation input, torsional deformation occurs in the tower, resulting in a ‘beat vibration’ phenomenon. Upon the incorporation of TLD/TLCD, the vibration response attenuation-ratio can reach up to 70 % under harmonic excitation, up to 25 % under seismic excitation and up to 50 % under equivalent base acceleration. After the implementation of vibration attenuation, there is a significant reduction in the time-domain response, and the rate of reduction is accelerated. In the frequency-domain response, the spectral peak at the natural-frequency disappears.</p></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":null,"pages":null},"PeriodicalIF":4.3,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142137436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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

Physics-informed neural network for the reconstruction of velocity and pressure of wave-in-deck loading from particle image velocimetry data 从粒子图像测速仪数据重建波浪在甲板上加载的速度和压力的物理信息神经网络

IF 4.3 2区工程技术

Applied Ocean Research Pub Date : 2024-09-03 DOI: 10.1016/j.apor.2024.104193

{"title":"Physics-informed neural network for the reconstruction of velocity and pressure of wave-in-deck loading from particle image velocimetry data","authors":"","doi":"10.1016/j.apor.2024.104193","DOIUrl":"10.1016/j.apor.2024.104193","url":null,"abstract":"<div><p>This study presents the application of physics-informed neural networks (PINN) to reconstruct the velocity and pressure of wave-in-deck (WID) loading phenomena based on particle image velocimetry (PIV) experiments in a 2D wave tank. The Euler equation for inviscid and incompressible fluids was adopted as the governing equation, and two boundary conditions were applied, with zero gauge pressure in air and zero vertical velocity on the deck bottom for the PINN. The free surface was reconstructed accurately by incorporating the loss term of the volume fraction into the total loss function. A learning rate annealing method and minibatch training strategy were used to achieve better training convergence. For a faster training process, the volume fraction was incorporated with the residual of the continuity equation and velocity loss. The velocity profile and pressure reconstructed by the PINN were compared with the velocity profile and pressure measured in the experiments and the pressure estimated by the PIV-based estimation methods, which revealed the advantages of the PINN in flow field reconstruction. The results showed that the PINN could be applied to reconstruct the velocity and pressure for the WID loading phenomena, and the pressure reconstructed by the PINN generally showed better agreement with the measured pressure than the pressure estimated by the PIV-based estimation methods. Additionally, proper implementation of governing equations and boundary conditions proved effective in mitigating the influence of measurement noise on the reconstructed results.</p></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":null,"pages":null},"PeriodicalIF":4.3,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142137435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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

Review of noise and vibration reduction technologies in marine machinery: Operational insights and engineering experience 审查船用机械的降噪减震技术：操作见解和工程经验

IF 4.3 2区工程技术

Applied Ocean Research Pub Date : 2024-08-30 DOI: 10.1016/j.apor.2024.104195

引用次数: 0

Analytical gradients of first-order diffraction and radiation forces for design optimization of floating structures 用于浮动结构优化设计的一阶衍射力和辐射力的分析梯度

IF 4.3 2区工程技术

Applied Ocean Research Pub Date : 2024-08-28 DOI: 10.1016/j.apor.2024.104198

{"title":"Analytical gradients of first-order diffraction and radiation forces for design optimization of floating structures","authors":"","doi":"10.1016/j.apor.2024.104198","DOIUrl":"10.1016/j.apor.2024.104198","url":null,"abstract":"<div><p>Gradient-based design optimization of floating structures with many design variables requires efficient and accurate computation of hydrodynamic coefficients including wave excitation forces and their derivatives with respect to design variables. For large-volume structures or structures with many component members, the only practical method to determine diffraction and radiation forces is to apply a boundary element method solver. This work presents the first known boundary element method solver with implicit analytic derivatives, allowing for total derivative computation alongside force evaluation. Two case studies are presented: a single floating circular column and a structure with multiple square columns attached to a horizontal pontoon. Force results from both case studies agree well with reference data, while derivative results agree with the best comparisons available. Computational requirements limit the applicability of this method and suggest further work is required to refine this approach.</p></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":null,"pages":null},"PeriodicalIF":4.3,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0141118724003195/pdfft?md5=e866a909ed814de4acc387f85dd6a794&pid=1-s2.0-S0141118724003195-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142088046","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Shallow water source depth discrimination based on a vertical linear array using deep learning 基于深度学习垂直线性阵列的浅水水源深度判别

IF 4.3 2区工程技术

Applied Ocean Research Pub Date : 2024-08-28 DOI: 10.1016/j.apor.2024.104201

{"title":"Shallow water source depth discrimination based on a vertical linear array using deep learning","authors":"","doi":"10.1016/j.apor.2024.104201","DOIUrl":"10.1016/j.apor.2024.104201","url":null,"abstract":"<div><p>This study aims to explore source depth discrimination in shallow water waveguides using a vertical line array. Due to the similarity in physical characteristics of features and environmental parameters, the feature distributions of shallow and deep sources overlap in feature space. This overlap is further exacerbated by strong background noise, reducing detection reliability. Therefore, a deep learning-based source depth discrimination (DL-SDD) scheme is proposed. Specifically, this scheme is based on a residual structure, embedding channel attention mechanisms into the deep structure to eliminate noise-related information gradually. Furthermore, a specially designed loss function considers inter-class and intra-class distances to achieve compact and mutually distant distributions of source features. When this loss function is applied, the overlap of source feature distributions is suppressed in end-to-end feature learning, leading to a high detection probability. The numerical simulations demonstrate that the proposed DL-SDD outperforms traditional method, achieving a 7 % increase in detection probability and a 15 % decrease in false alarm rate, even near the discrimination depth. Furthermore, the discrimination depth is reduced by nearly half. Experimental results from the South China Sea validate the effectiveness of the proposed DL-SDD.</p></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":null,"pages":null},"PeriodicalIF":4.3,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142088047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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

Design and development of a new stand-alone profiler for marine monitoring purposes 设计和开发用于海洋监测的新型独立式剖面仪

IF 4.3 2区工程技术

Applied Ocean Research Pub Date : 2024-08-28 DOI: 10.1016/j.apor.2024.104199

{"title":"Design and development of a new stand-alone profiler for marine monitoring purposes","authors":"","doi":"10.1016/j.apor.2024.104199","DOIUrl":"10.1016/j.apor.2024.104199","url":null,"abstract":"<div><p>Marine pollution is a complex issue that has prompted extensive research. The Mar Menor lagoon, a singular Mediterranean ecological feature, is under pressure from various economic activities, leading to episodes of hypoxia and fish mass mortality. The lagoon is covered by an extensive meadow of submerged vegetation that release oxygen during daylight hours but consumes it during the night. Under exceptional conditions, the water column becomes stratified, with higher oxygen consumption in the deeper layers due to organic matter decomposition. Therefore, continuous high-frequency monitoring of critical parameters affecting the metabolic behaviour of the lagoon is essential. This marine environment has traditionally been monitored with traditional techniques from vessels on a weekly basis, incurring in high costs and yielding limited results. This article introduces the s-Nautilus, a submersible profiler that enables near real-time data transmission in shallow marine environments. It showcases an operational autonomy of two months and significantly reduces installation costs by eliminating the need for on-site infrastructure and personnel. Weighing 21 kg, makes it easy to transport, and it can be equipped with different commercial sensors to monitor various parameters as required. Currently, several s-Nautilus profilers are deployed in the Mar Menor lagoon, collecting data during critical hours, and providing valuable information to the managers of this emblematic environment.</p></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":null,"pages":null},"PeriodicalIF":4.3,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0141118724003201/pdfft?md5=4f342ae1b99ecc1a3092733e2e26c7ba&pid=1-s2.0-S0141118724003201-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142088048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A new soft-computing approach for stability evaluation of inclined circular anchor in natural clays 天然粘土中倾斜圆锚稳定性评估的新型软计算方法

IF 4.3 2区工程技术

Applied Ocean Research Pub Date : 2024-08-27 DOI: 10.1016/j.apor.2024.104166

{"title":"A new soft-computing approach for stability evaluation of inclined circular anchor in natural clays","authors":"","doi":"10.1016/j.apor.2024.104166","DOIUrl":"10.1016/j.apor.2024.104166","url":null,"abstract":"<div><p>A novel approach based on the coupling of Finite Element Limit Analysis (FELA) and Artificial Neural Network (ANN) is adopted to investigate the effect of the inclination angle and the natural clay properties on the uplift resistance of inclined circular anchors embedded in anisotropic and non-homogenous clays. Totally 1296 3D FELA models with the Anisotropic Undrained Shear (AUS) model are implemented, and an optimal ANN model is selected for investigating the effects of four design parameters on uplift factor (<em>F<sub>c</sub></em>), including inclined angle (<em>θ</em>), embedment ratio (<em>H/D</em>), anisotropic ratio (<em>r<sub>e</sub></em>), and non-homogenous ratio (<em>m</em>). Specifically, the uplift resistance of inclined circular anchors is strongly affected by <em>H/D</em>, followed by <em>m, θ</em>, and <em>r<sub>e</sub></em>, with importance indexes of 44.1%, 37.9%, 15.0%, and 3.0%, respectively. For practical application, this study proposes a correlation equation between four design parameters and uplift factor (<em>F<sub>c</sub></em>) with high accuracy, which can be helpful in quickly estimating the uplift resistance. Additionally, the design charts that show detailed relationships between <em>F<sub>c</sub></em> and investigated parameters (<em>θ, m, H/D</em>, and <em>r<sub>e</sub></em>) and the failure mechanism of the inclined anchors are also illustrated in this research. These investigations can significantly enhance the understanding of the performance of inclined circular anchors embedded in anisotropic and non-homogenous clays.</p></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":null,"pages":null},"PeriodicalIF":4.3,"publicationDate":"2024-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142083802","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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

Boussinesq model for two-fluid system with surface- and interfacial tension 具有表面张力和界面张力的双流体系统的布森斯克模型

IF 4.3 2区工程技术

Applied Ocean Research Pub Date : 2024-08-27 DOI: 10.1016/j.apor.2024.104183

{"title":"Boussinesq model for two-fluid system with surface- and interfacial tension","authors":"","doi":"10.1016/j.apor.2024.104183","DOIUrl":"10.1016/j.apor.2024.104183","url":null,"abstract":"<div><p>A Boussinesq model associated with surface and internal waves with surface tension and interfacial tension in a two-layer fluid is presented in the application range of weakly dispersive nonlinear. The nonlinear form of model definitions in terms of surface and interfacial tensions along with velocity potentials are provided. Based on the perturbation technique, the Boussinesq equations for both layers are derived. The present Boussinesq result is validated against existing published results and it has a good level of agreement. Further, the present model results of crests of surface and interface displacements are compared with existing published numerical OpenFOAM simulations. The dispersion relations for fast- and slow modes are derived in the quadratic form of wave frequencies in the presence of surface and interfacial tensions. The second-order surface and internal wave displacements along with velocity potentials for upper- and lower-layer fluids are presented. The effects of surface and interfacial tensions on dispersion characteristics, harmonic transfer functions, and shoaling gradients on different physical parameters associated with the present model are studied by analyzing several numerical results. In the end, a real physical problem is demonstrated in the application of surface tension with solvents in the gas-liquid interface.</p></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":null,"pages":null},"PeriodicalIF":4.3,"publicationDate":"2024-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0141118724003043/pdfft?md5=ebd929ca923e515ec2bc26154c1c281c&pid=1-s2.0-S0141118724003043-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142083800","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

An efficient model for small object detection in the maritime environment 海洋环境中小物体检测的高效模型

IF 4.3 2区工程技术

Applied Ocean Research Pub Date : 2024-08-27 DOI: 10.1016/j.apor.2024.104194

{"title":"An efficient model for small object detection in the maritime environment","authors":"","doi":"10.1016/j.apor.2024.104194","DOIUrl":"10.1016/j.apor.2024.104194","url":null,"abstract":"<div><p>Environmental perception is crucial for autonomous ships realizing autonomous navigation, in particular, the high-precision and low-latency detection of small objects on the sea surface is a key and challenging issue. To address this problem, this paper presents a model that improves the detection accuracy and delivers excellent real-time performance for autonomous ship navigation. The backbone of the proposed model enhances the modelling capabilities by expanding deformable convolution and introducing the self-designed attention mechanism. Additionally, an enhanced feature fusion structure is designed by the pixel shuffle based on super-resolution reconstruction to keep the integrity of feature information for small objects. This paper also presents an optimized model quantization strategy that alleviates the problem of low model efficiency caused by the limited resources onboard the ship. Compared to the earlier model, the present one has increased the mean average precision on the Rizhao Zhuimeng-3# maritime optical dataset by 4.5 % and by 21 % for small object detection. Furthermore, the real-time detection for high-resolution images can now reach a speed of 67 frames/s. Moreover, the present model outperforms existing methods concerning accuracy when the frames/s are similar. The results indicate that the proposed model can be potentially applied to autonomous ships.</p></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":null,"pages":null},"PeriodicalIF":4.3,"publicationDate":"2024-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142083801","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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