International Journal of Naval Architecture and Ocean Engineering最新文献

{"title":"A systematic study on the influence of scale, hull roughness, and draft on form factor estimation","authors":"Minas Argyros ,&nbsp;Simone Mancini ,&nbsp;Kadir Burak Korkmaz ,&nbsp;Arash Eslamdoost","doi":"10.1016/j.ijnaoe.2025.100739","DOIUrl":"10.1016/j.ijnaoe.2025.100739","url":null,"abstract":"<div><div>In recent years, considerable attention has been given to the prediction of form factor of ships and the associated scale effects, as the accuracy of such estimations has come under scrutiny. This paper explores the discrepancies between model-scale and full-scale form factor predictions derived from CFD simulations using a newly developed approach known as the <em>2-</em><span><math><mi>k</mi></math></span> method. This method enhances the precision of form factor evaluation, particularly when applied at full scale, showing notable improvements for hulls with wetted transoms. This study tests the hypothesis of 2-k and transom correction methods with different numerical tools and methods. It reveals a strong dependence of the form factor on grid resolution across different scales, while aligning well with findings reported in the literature. Additionally, a sensitivity analysis based on uniformly distributed surface roughness is performed. The <em>2-</em><span><math><mi>k</mi></math></span> method is also applied to systematically varied transom submergence conditions, demonstrating consistent form factor trends across both model and full scales. Furthermore, when evaluating draft variations, the method yields results that more closely match experimental data. These findings suggest that the <em>2-</em><span><math><mi>k</mi></math></span> method is a reliable tool for estimating the form factor in scenarios involving complex turbulent flow, such as in the wake of the transom.</div></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"18 ","pages":"Article 100739"},"PeriodicalIF":3.9,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146034415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Predicting ship hull flow-field distributions using a soft-constrained ANN model","authors":"Christoforos Lefkiou ,&nbsp;Phoevos (Foivos) Koukouvinis ,&nbsp;Sotirios Chatzis ,&nbsp;Stefanos Xyfolis","doi":"10.1016/j.ijnaoe.2025.100712","DOIUrl":"10.1016/j.ijnaoe.2025.100712","url":null,"abstract":"<div><div>Accurate determination of shear and pressure force distributions around a ship's hull is paramount for hydrodynamic optimization tasks, as integrating these fields across the hull's surface provides the total drag force applied on the hull. While Computational Fluid Dynamics (CFD) provides this capability, it is often limited by high computational cost and time-consuming pre-processing, post-processing, and simulation times. The challenge is further amplified during design exploration studies, where simulations are performed across multiple operational conditions. To address these limitations, we propose a soft-constrained Multitask deep neural network, named HydroForceNet, which serves as a surrogate model for CFD simulations on marine vessel hulls. Our proposed architecture can accurately predict pressure and shear distributions on various Wigley-based geometries and calculates the resistance components, using three-dimensional geometric and operational inputs, at a fraction of the computational cost of a traditional CFD evaluation. Finally, to further illustrate its applicability, the proposed artificial neural network is integrated into a genetic algorithm-based optimization task, producing a new hull geometry with a 15.77 % reduction of hydrodynamic resistance compared to a reference hull geometry, after evaluating over 2500 designs within 2 min, while faithfully reproducing the flow field.</div></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"18 ","pages":"Article 100712"},"PeriodicalIF":3.9,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145788875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mathematical modeling and simulation of variable morphing multi-body AUVs for underwater structure maintenance","authors":"Longchuan Li ,&nbsp;Yuan He ,&nbsp;Yuxi Gao ,&nbsp;Jin Zhang ,&nbsp;Yunfei Bai ,&nbsp;Shuai Kang","doi":"10.1016/j.ijnaoe.2026.100768","DOIUrl":"10.1016/j.ijnaoe.2026.100768","url":null,"abstract":"<div><div>Achieving both stability and adaptability is a central challenge for multibody autonomous underwater vehicles (AUVs) operating in complex marine environments. This paper develops a unified mathematical modeling framework that integrates hydrostatic regulation and morphological reconfiguration. Three mechanisms are formulated: buoyancy adjustment for quasi-static equilibrium control, aperture-angle variation for dynamic angular morphing, and linkage-length modulation for geometric–spatial morphing. Numerical simulations based on the derived nonlinear dynamics evaluate their effects under roll disturbances. Results show that compact morphs yield rapid but oscillatory recovery, extended morphs enhance stability at the cost of slower convergence, and intermediate settings provide balanced performance. Phase-space trajectories and posture recovery diagrams confirm the distinct yet complementary roles of the three mechanisms. The study paves the way for the dynamics analysis and control of variable-morphing multibody systems, offering insights into stability–adaptability trade-offs and providing a foundation for future work on fluid–structure interaction, optimization, and digital-twin applications in underwater robotics.</div></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"18 ","pages":"Article 100768"},"PeriodicalIF":3.9,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147995806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of a standard series for pump-jet propulsors and data-driven regression for performance prediction","authors":"Jinghan Su ,&nbsp;Youjiang Wang ,&nbsp;Fang Li ,&nbsp;Li Zhou","doi":"10.1016/j.ijnaoe.2026.100765","DOIUrl":"10.1016/j.ijnaoe.2026.100765","url":null,"abstract":"<div><div>Pump-jet propulsors are widely used in marine applications because of their advantages in propulsive efficiency, cavitation performance, and low noise performance. However, the lack of a standard series database still limits rapid preliminary design and systematic performance comparison of pump-Jet propulsors. To address this issue, this study develops the Standard Pump-Jet Propulsor Series A (SPJP-A) and corresponding data driven regression formulae for open water performance prediction. The proposed series comprises 240 systematically parameterized configurations covering variations in pitch ratio, blade area ratio, stator exit angle, rotor blade number, and stator blade number. A stator exit angle based characterization is introduced to improve the geometric description of rotor–stator matching. Open water performance is evaluated using validated RANS simulations, from which 3801 grid independent operating points are obtained. For the representative validation case, the average error in open water characteristics is below 5%. On this basis, stepwise polynomial regression models with forward selection are established for the main performance coefficients within the SPJP-A design envelope. The models show high predictive accuracy, with cross validation R² values above 0.999 for all modeled coefficients, while independent test cases yield MAE below 0.021 and RMSE below 0.024. The results also show that rotor–stator torque equilibrium does not necessarily correspond to maximum propulsive efficiency. For some configurations, the highest efficiency occurs under non balanced torque sharing. The proposed SPJP-A series and regression formulae provide a transparent and reproducible tool for preliminary Pump-Jet design, enabling rapid performance evaluation within the prescribed parameter range without repeated CFD simulations.</div></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"18 ","pages":"Article 100765"},"PeriodicalIF":3.9,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147849562","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Autonomous recovery of an AUV to a submarine using a potential field considering navigation uncertainty and collision risk","authors":"Seunghyuk Choi,&nbsp;Jongdae Jung","doi":"10.1016/j.ijnaoe.2026.100779","DOIUrl":"10.1016/j.ijnaoe.2026.100779","url":null,"abstract":"<div><div>Autonomous underwater vehicles (AUVs) are increasingly employed in marine exploration and reconnaissance, frequently in conjunction with submarines. However, the inherent uncertainty regarding the positional accuracy of the AUV and the submarine in underwater environments presents a significant risk of collision, particularly during recovery operations. This paper proposes an uncertainty aware guidance framework for recovering an AUV to a moving submarine. The AUV and submarine positions and covariances are estimated by an extended Kalman filter (EKF) based inertial navigation system. These covariances are used to inflate the hull geometries into configuration-space collision-risk zones. A three-dimensional extension of the time to closest point of approach (TCPA) and distance at closest point of approach (DCPA) is then mapped into a Mamdani fuzzy-logic system to produce a scalar collision-risk index. This index is coupled with a potential field guidance law whose repulsive component is padded by the EKF covariance, and with a risk dependent speed modulation that adjusts the AUV surge velocity. In a Monte Carlo campaign of 10,000 randomized encounters, the proposed fuzzy TCPA–DCPA metric achieved an area under the ROC curve of 0.92 and a Youden optimal decision threshold of 0.85, corresponding to a true-positive rate of 0.80 at a false-positive rate of 0.10. High-fidelity simulations in the Stonefish environment, including hydrodynamics and rigid-body collisions, show that conventional kinematic guidance and a naïve potential field result in collisions in quartering approaches. In contrast, the proposed uncertainty-aware potential field and speed-modulation strategy eliminate collisions and reduce the peak collision risk index from 0.88 to 0.69 while still enabling successful docking. These results indicate that explicitly incorporating navigation uncertainty into both collision-risk assessment and guidance substantially improves the safety of AUV–submarine recovery operations.</div></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"18 ","pages":"Article 100779"},"PeriodicalIF":4.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148539779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"LMSD-Net : A lightweight multi-scale ship detection network based on RAPNet","authors":"Weigui Nan ,&nbsp;Rui Fan ,&nbsp;Renhao Jiao ,&nbsp;Jin Dang ,&nbsp;Zhixue Wang ,&nbsp;Xuefeng Ge ,&nbsp;Lihong Chang ,&nbsp;Baiying Dong ,&nbsp;Xiaoli Luo","doi":"10.1016/j.ijnaoe.2026.100772","DOIUrl":"10.1016/j.ijnaoe.2026.100772","url":null,"abstract":"<div><div>Ship detection driven by computer vision is the key link of intelligent port management. The main contradiction currently facing is that the computational complexity of the traditional deep learning model is too high to meet the actual deployment requirements; the over-lightweight model often leads to a significant decrease in detection accuracy due to insufficient feature expression ability. To address these issues, this study proposes a lightweight multi-scale ship detection network named LMSD-Net, based on RAPNet. The model effectively combines the efficient feature extraction capabilities of RapidNet with the multi-scale path aggregation abilities of PANet, constructing a RAPNet backbone network that boasts strong computational efficiency and feature representation capabilities. A multi-branch parallel architecture for multi-scale feature fusion is designed to enhance feature learning. An efficient multi-scale attention mechanism is introduced to improve the focusing ability on key features. To address the characteristics of small ship targets, a Lighting-Occlusion Attention Mechanism, combining mixed attention and residual connections, is embedded in the small target detection head to effectively mitigate noise interference and information degradation. Experiments on the SeaShips and SSDD (SAR ship monitoring dataset) demonstrate that LMSD-Net achieves 52.2% and 73.7% mAP@50:95 with 0.5M parameters and 2.3GFLOPs computational cost, respectively. Compared to YOLO11n, which has 2.58M parameters and 6.3GFLOPs computational cost, LMSD-Net increases mAP@50:95 by 2.5% and 1.1%, reduces parameter count by 80.6%, and decreases computational cost by 63.5%, showing excellent edge deployment potential.</div></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"18 ","pages":"Article 100772"},"PeriodicalIF":3.9,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148241217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Case-based reasoning for optimal arrangement and passageway of ship engine room","authors":"Moon-Su Kim,&nbsp;Ki-Su Kim,&nbsp;Yu Jun Choi","doi":"10.1016/j.ijnaoe.2026.100762","DOIUrl":"10.1016/j.ijnaoe.2026.100762","url":null,"abstract":"<div><div>The ship engine room is a complex design space requiring the simultaneous satisfaction of various constraints, including pipe connectivity, maintenance accessibility, and spatial utilization. Despite its complexity, engine room equipment arrangement still heavily relies on expert experience and manual operations, often leading to inconsistent design quality. This study proposes a systematic optimal arrangement design framework that integrates Case-Based Reasoning (CBR) with a multi-objective optimization approach. To quantify and reuse the implicit knowledge embedded in existing designs, we represent engine room configurations as system-wise graphs and employ Graph Edit Distance (GED) to calculate structural similarity between target and past designs. This similarity is utilized as a key objective function within the NSGA-II optimization algorithm, alongside objectives for minimizing pipe length and maximizing spatial efficiency. Furthermore, we introduce an automated passageway generation method using Generalized Voronoi Diagrams (GVD) and skeletonization to ensure design feasibility and accessibility. The framework was validated through three case studies, where the results demonstrated that the proposed method effectively preserves realistic arrangement patterns while significantly improving spatial utilization and accessibility compared to conventional optimization techniques. This approach provides a robust decision-making tool for designers, reducing dependency on individual expertise and enhancing overall design consistency.</div></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"18 ","pages":"Article 100762"},"PeriodicalIF":3.9,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147749698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Anti-swing overhead crane control algorithm based on multi-body dynamics using reinforcement learning","authors":"Jun-Gi Jang,&nbsp;Seung-Ho Ham","doi":"10.1016/j.ijnaoe.2025.100719","DOIUrl":"10.1016/j.ijnaoe.2025.100719","url":null,"abstract":"<div><div>Excessive cargo sway during crane operations in the current shipbuilding industry is a major problem that causes safety accidents and work delays. Therefore, the development of stable crane control technology is essential. In this study, a crane control algorithm that simultaneously achieves accurate movement to target positions and sway minimization was developed using reinforcement learning. In dynamics modeling, the Discrete Euler-Lagrange Equation was applied to significantly reduce the computational complexity of existing methods, and the Proximal Policy Optimization (PPO) method was used for control policy learning. A three-dimensional virtual environment was constructed to perform learning under various travel distances and operating conditions, and the performance of the developed algorithm was compared and verified against the traditional trapezoidal velocity profile. Experimental results showed that the proposed method exhibited significant improvements in position control precision and sway suppression performance compared to existing methods. The results of this study are expected to contribute to the implementation of automated crane control systems in actual shipyard environments.</div></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"18 ","pages":"Article 100719"},"PeriodicalIF":3.9,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145789131","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Underwater acoustic absorbing materials with multiple air cavities: Modeling and validation","authors":"Jaeman Kim ,&nbsp;Dae-Seung Cho ,&nbsp;Kookhyun Kim ,&nbsp;Kyungjun Song","doi":"10.1016/j.ijnaoe.2026.100759","DOIUrl":"10.1016/j.ijnaoe.2026.100759","url":null,"abstract":"<div><div>An analytical method for calculating the acoustic performance of underwater acoustic absorbing materials with multiple air cavities is derived and verified using numerical method. The underwater acoustic absorbing material consist of a rubber-based absorber with five cylindrical air cavities embedded along the rotating axis. Several geometric configurations of the air cavities are analyzed with both the proposed analytical method and the numerical method. Predictions obtained using the transfer matrix method, developed based on effective medium theory, show strong agreement with the numerical simulations in the low-frequency range, thereby validating the proposed analytical approach. The presence of air cavities significantly improves the absorption coefficient by enhancing local rubber deformation and energy dissipation. Increasing the cavity volume shifts the absorption peak toward lower frequencies due to a reduction in effective wave speed and a resulting slow-wave effect. In addition, reducing the spacing between adjacent cavities further improves absorption, as the gradual impedance transition facilitates wave penetration and enhances overall energy loss. These results demonstrate that the configuration of the air-layer cavity plays a crucial role in optimizing the acoustic performance of underwater acoustic absorbing materials.</div></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"18 ","pages":"Article 100759"},"PeriodicalIF":3.9,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147703143","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hybrid model identification and prediction for docking and crabbing motions of a leisure boat","authors":"Ji Young Seo,&nbsp;Hyo-Jin Park,&nbsp;Hujae Choi,&nbsp;Bo Woo Nam","doi":"10.1016/j.ijnaoe.2026.100781","DOIUrl":"10.1016/j.ijnaoe.2026.100781","url":null,"abstract":"<div><div>Accurate and reliable maneuvering models for leisure boats are crucial for the development of safe navigation and automatic docking solutions. Predicting the docking and crabbing motions of leisure boats presents significant challenges due to the nonlinear characteristics of low-speed operations and the intricate propulsion systems. In this paper, maneuvering models for docking and crabbing operations were examined using various system identification (SI) methodologies. These models were identified with three different approaches; white-box, black-box, and gray-box. The white-box-based SI methodology mathematically identifies the maneuvering model, incorporating the hull force models based on modified MMG models and propeller-rudder force models designed to account for the interaction effects between propellers and rudders. The black-box approach develops a data-driven model to predict the maneuvering dynamics of leisure boats. To determine the optimal black-box model, performances of basic recurrent neural networks (RNNs), long short-term memory (LSTM), gated recurrent unit (GRU), combined with additional layers such as convolutional neural networks (CNNs) and Transformer, time distributed layer, were compared. The gray-box model integrates both the white-box and black-box models to leverage the advantages of both the physical and the data-driven models. The results demonstrated that the gray-box model offers the highest prediction accuracy for the maneuvering model, thereby proving the value of a hybrid approach that combines domain knowledge and artificial intelligence in identifying ship maneuvering models.</div></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"18 ","pages":"Article 100781"},"PeriodicalIF":4.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148539344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}