Pub Date : 2025-01-01DOI: 10.1016/j.ijnaoe.2025.100644
Son Tung Vu , Thai Duong Nguyen , Hai Van Dang , Van Suong Nguyen
This paper develops a robust controller for automatic ship berthing subjected to actuator faults, input saturation, modeling uncertainties, and external disturbances. First, sliding mode control (SMC) is used as a core controller to provide robust features for the ship berthing system. Second, fault-tolerant control (FTC) is combined with the controller to face the actuator faults. Third, the radial basis function (RBF) neural network is employed to approximate the modeling uncertainties while the effect of external disturbances is compensated by an adaptive control technique. In addition, an anti-saturation auxiliary system is conducted to deal with the input saturation for physical limitations of the actuators. Finally, numerical simulation and comparison of the results with the other control approaches are carried out to highlight the advantages of the proposed controller.
{"title":"Adaptive neural network fault-tolerant sliding mode control for ship berthing with actuator faults and input saturation","authors":"Son Tung Vu , Thai Duong Nguyen , Hai Van Dang , Van Suong Nguyen","doi":"10.1016/j.ijnaoe.2025.100644","DOIUrl":"10.1016/j.ijnaoe.2025.100644","url":null,"abstract":"<div><div>This paper develops a robust controller for automatic ship berthing subjected to actuator faults, input saturation, modeling uncertainties, and external disturbances. First, sliding mode control (SMC) is used as a core controller to provide robust features for the ship berthing system. Second, fault-tolerant control (FTC) is combined with the controller to face the actuator faults. Third, the radial basis function (RBF) neural network is employed to approximate the modeling uncertainties while the effect of external disturbances is compensated by an adaptive control technique. In addition, an anti-saturation auxiliary system is conducted to deal with the input saturation for physical limitations of the actuators. Finally, numerical simulation and comparison of the results with the other control approaches are carried out to highlight the advantages of the proposed controller.</div></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"17 ","pages":"Article 100644"},"PeriodicalIF":2.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143164718","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}
Pub Date : 2025-01-01DOI: 10.1016/j.ijnaoe.2025.100655
Dong-Jin Kim, Haeseong Ahn, Dong Jin Yeo
In this study, powering and manoeuvring performance of a twin-screw surface combatant, ONR tumblehome (ONRT), are estimated through towing tank captive model tests, and influences of appendage dimensions on its course-stabilities and manoeuvres are investigated by system-based simulation techniques. At first, resistance and propulsion tests are carried out at Froude numbers up to 0.4 in the towing tank of Korea Research Institute of Ships and Ocean Engineering (KRISO) so that its full-scale powering performance can be considered in the present simulation model. In particular, the residuary resistance is significantly affected by patterns of hull generated waves. Secondly, horizontal planar motion mechanism (HPMM) tests are performed to derive hydrodynamic coefficients in surge, sway, and yaw directions. By using 3-DoF modular-type models, turn and zig-zag manoeuvres are simulated, and simulations are validated with existing benchmark free-run model tests. Sway-yaw coupled linear whole ship models are also established in order to assess a straight-line stability of a rudder-fixed ONRT whole ship. Linear hydrodynamic coefficients are decomposed into hull and appendage components so that influences of appendage dimensions on ship manoeuvres can be analyzed in more detail. When the rudder area is enlarged or reduced, the coefficient and the location of a centerline skeg are redesigned under the constraint straight-line stabilities are identical. For one original ONRT and two modified ships, turn and zig-zag manoeuvres are simulated by linear whole ship models. Even though straight-line stabilities are identical, the turning diameter is decreased while zig-zag overshoot angles are increased with increasing rudder area. To ensure sufficient manoeuvrabilities of such a twin-screw ship, careful attentions should be paid to design of a centerline skeg and rudders.
{"title":"Horizontal plane course-stability and manoeuvres of a twin-screw surface combatant depending on appendage dimensions","authors":"Dong-Jin Kim, Haeseong Ahn, Dong Jin Yeo","doi":"10.1016/j.ijnaoe.2025.100655","DOIUrl":"10.1016/j.ijnaoe.2025.100655","url":null,"abstract":"<div><div>In this study, powering and manoeuvring performance of a twin-screw surface combatant, ONR tumblehome (ONRT), are estimated through towing tank captive model tests, and influences of appendage dimensions on its course-stabilities and manoeuvres are investigated by system-based simulation techniques. At first, resistance and propulsion tests are carried out at Froude numbers up to 0.4 in the towing tank of Korea Research Institute of Ships and Ocean Engineering (KRISO) so that its full-scale powering performance can be considered in the present simulation model. In particular, the residuary resistance is significantly affected by patterns of hull generated waves. Secondly, horizontal planar motion mechanism (HPMM) tests are performed to derive hydrodynamic coefficients in surge, sway, and yaw directions. By using 3-DoF modular-type models, turn and zig-zag manoeuvres are simulated, and simulations are validated with existing benchmark free-run model tests. Sway-yaw coupled linear whole ship models are also established in order to assess a straight-line stability of a rudder-fixed ONRT whole ship. Linear hydrodynamic coefficients are decomposed into hull and appendage components so that influences of appendage dimensions on ship manoeuvres can be analyzed in more detail. When the rudder area is enlarged or reduced, the coefficient and the location of a centerline skeg are redesigned under the constraint straight-line stabilities are identical. For one original ONRT and two modified ships, turn and zig-zag manoeuvres are simulated by linear whole ship models. Even though straight-line stabilities are identical, the turning diameter is decreased while zig-zag overshoot angles are increased with increasing rudder area. To ensure sufficient manoeuvrabilities of such a twin-screw ship, careful attentions should be paid to design of a centerline skeg and rudders.</div></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"17 ","pages":"Article 100655"},"PeriodicalIF":2.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738100","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}
Pub Date : 2025-01-01DOI: 10.1016/j.ijnaoe.2025.100646
Jiseung Lee , Wonjun Jo , Junseok Seo , Gyubaek An
This study evaluates the effect of notch shape on the fracture toughness of a 500 MPa base material designed for liquefied carbon dioxide storage tanks. This study specifically focuses on assessing the crack tip opening displacement (CTOD) values for different notch shapes, including fatigue pre-cracks (R = 0.025 mm) and electrical discharge machining (EDM) notches (R = 0.07 mm and R = 0.15 mm). CTOD tests were conducted over a temperature range of −55 °C to −140 °C. The results revealed that as the notch radius increased, the degree of stress concentration decreased, leading to an increase in fracture toughness. In temperature-dependent tests, CTOD values consistently decreased as the temperature decreased, with EDM notches exhibiting a lower rate of fracture toughness reduction compared to fatigue pre-cracks, which is attributed to differences in the degree of stress concentration. Scanning electron microscopy analysis of the fracture surfaces revealed the reason for significant differences in CTOD values and fracture behaviors between fatigue pre-crack and EDM notches, particularly at −140 °C, a temperature below the ductile to brittle transition temperature. This study suggests that EDM notches, especially with radii of 0.07 mm and 0.15 mm, can effectively replace fatigue pre-cracks in CTOD evaluations, particularly at temperatures above the transition temperature, offering a more efficient method for assessing fracture toughness in cryogenic environments.
{"title":"Effect of notch shape on the fracture toughness behavior","authors":"Jiseung Lee , Wonjun Jo , Junseok Seo , Gyubaek An","doi":"10.1016/j.ijnaoe.2025.100646","DOIUrl":"10.1016/j.ijnaoe.2025.100646","url":null,"abstract":"<div><div>This study evaluates the effect of notch shape on the fracture toughness of a 500 MPa base material designed for liquefied carbon dioxide storage tanks. This study specifically focuses on assessing the crack tip opening displacement (CTOD) values for different notch shapes, including fatigue pre-cracks (R = 0.025 mm) and electrical discharge machining (EDM) notches (R = 0.07 mm and R = 0.15 mm). CTOD tests were conducted over a temperature range of −55 °C to −140 °C. The results revealed that as the notch radius increased, the degree of stress concentration decreased, leading to an increase in fracture toughness. In temperature-dependent tests, CTOD values consistently decreased as the temperature decreased, with EDM notches exhibiting a lower rate of fracture toughness reduction compared to fatigue pre-cracks, which is attributed to differences in the degree of stress concentration. Scanning electron microscopy analysis of the fracture surfaces revealed the reason for significant differences in CTOD values and fracture behaviors between fatigue pre-crack and EDM notches, particularly at −140 °C, a temperature below the ductile to brittle transition temperature. This study suggests that EDM notches, especially with radii of 0.07 mm and 0.15 mm, can effectively replace fatigue pre-cracks in CTOD evaluations, particularly at temperatures above the transition temperature, offering a more efficient method for assessing fracture toughness in cryogenic environments.</div></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"17 ","pages":"Article 100646"},"PeriodicalIF":2.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143348296","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}
Pub Date : 2025-01-01DOI: 10.1016/j.ijnaoe.2025.100662
Kyeongho Kim, ChangSeop Kwon, Sanghwan Kim
This study presents a comprehensive economic and technical feasibility analysis of a 15,000 TEU containership powered by small modular reactor (SMR) technology. The analysis evaluates capital expenditures (CAPEX) and operational expenditures (OPEX) across multiple scenarios, focusing on key factors such as reactor manufacturing costs, nuclear fuel prices, and carbon tax rates. The study also explores the financial implications of leasing versus purchasing the SMR unit, providing a comparison of long-term profitability, cash flow stability, and risk management. Results show that nuclear-powered vessels offer significant long-term cost advantages, particularly in fuel savings and carbon tax reductions, despite their higher initial CAPEX. Leasing the SMR presents an attractive alternative by reducing upfront investment and offering financial flexibility, though at the expense of slightly lower long-term net present value (NPV). This analysis demonstrates the potential benefits of nuclear propulsion in commercial shipping.
{"title":"A conceptual study of 15,000 TEU SMR-powered containerships","authors":"Kyeongho Kim, ChangSeop Kwon, Sanghwan Kim","doi":"10.1016/j.ijnaoe.2025.100662","DOIUrl":"10.1016/j.ijnaoe.2025.100662","url":null,"abstract":"<div><div>This study presents a comprehensive economic and technical feasibility analysis of a 15,000 TEU containership powered by small modular reactor (SMR) technology. The analysis evaluates capital expenditures (CAPEX) and operational expenditures (OPEX) across multiple scenarios, focusing on key factors such as reactor manufacturing costs, nuclear fuel prices, and carbon tax rates. The study also explores the financial implications of leasing versus purchasing the SMR unit, providing a comparison of long-term profitability, cash flow stability, and risk management. Results show that nuclear-powered vessels offer significant long-term cost advantages, particularly in fuel savings and carbon tax reductions, despite their higher initial CAPEX. Leasing the SMR presents an attractive alternative by reducing upfront investment and offering financial flexibility, though at the expense of slightly lower long-term net present value (NPV). This analysis demonstrates the potential benefits of nuclear propulsion in commercial shipping.</div></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"17 ","pages":"Article 100662"},"PeriodicalIF":2.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144185762","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}
Pub Date : 2025-01-01DOI: 10.1016/j.ijnaoe.2025.100671
Xiaodi Liang, Yindong Liu, Siqi Wang
This study introduces an innovative approach for the rapid prediction of shock spectrum in ship structures subjected to underwater far-field explosion loads. A nine-compartment ship model is developed, with 31 test condition sets designed. For each set, sample measurement points are strategically placed at typical locations across various deck levels and on the inner and outer bottoms of the double bottom at different frame cross-sections. Shock spectrum (including spectral velocity, acceleration, and displacement) are extracted from these sample points to establish a comprehensive shock spectrum database. Using the Kolmogorov-Arnold Network, a rapid prediction model for ship structure shock spectrum is developed. The network's inputs include ship structural formal parameters (e.g., number and position of decks, transverse and longitudinal bulkheads), impact factors, feature transfer distances, and local shock factors. Spectral velocity, acceleration, and displacement are used as the network's outputs during training. A comparative analysis of prediction accuracy among the Kolmogorov-Arnold Network, Backpropagation Network, and Convolutional Neural Network is conducted. The results demonstrate that the Kolmogorov-Arnold Network exhibits superior predictive accuracy compared to the Backpropagation and Convolutional Neural Networks. In contrast to existing finite element simulation methods, the proposed approach is simpler and more practical. Furthermore, unlike current rapid prediction methods, the proposed method takes into account the influence of ship structural characteristics on underwater explosion shock responses, making it better suited to the requirements for rapid prediction of underwater far-field explosion shock spectrum in ship structures.
{"title":"A Kolmogorov-Arnold network-based method for predicting underwater explosion shock spectrum considering cabin structural characteristics","authors":"Xiaodi Liang, Yindong Liu, Siqi Wang","doi":"10.1016/j.ijnaoe.2025.100671","DOIUrl":"10.1016/j.ijnaoe.2025.100671","url":null,"abstract":"<div><div>This study introduces an innovative approach for the rapid prediction of shock spectrum in ship structures subjected to underwater far-field explosion loads. A nine-compartment ship model is developed, with 31 test condition sets designed. For each set, sample measurement points are strategically placed at typical locations across various deck levels and on the inner and outer bottoms of the double bottom at different frame cross-sections. Shock spectrum (including spectral velocity, acceleration, and displacement) are extracted from these sample points to establish a comprehensive shock spectrum database. Using the Kolmogorov-Arnold Network, a rapid prediction model for ship structure shock spectrum is developed. The network's inputs include ship structural formal parameters (e.g., number and position of decks, transverse and longitudinal bulkheads), impact factors, feature transfer distances, and local shock factors. Spectral velocity, acceleration, and displacement are used as the network's outputs during training. A comparative analysis of prediction accuracy among the Kolmogorov-Arnold Network, Backpropagation Network, and Convolutional Neural Network is conducted. The results demonstrate that the Kolmogorov-Arnold Network exhibits superior predictive accuracy compared to the Backpropagation and Convolutional Neural Networks. In contrast to existing finite element simulation methods, the proposed approach is simpler and more practical. Furthermore, unlike current rapid prediction methods, the proposed method takes into account the influence of ship structural characteristics on underwater explosion shock responses, making it better suited to the requirements for rapid prediction of underwater far-field explosion shock spectrum in ship structures.</div></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"17 ","pages":"Article 100671"},"PeriodicalIF":2.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144685569","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}
This paper proposes a novel fixed-time path-following control strategy for underactuated ships with input delay. Firstly, the fractional power is employed in the controller design to obtain the fast system convergence. Then, a fixed-time dynamic surface control (FTDSC) technique is presented to approximate the analytic derivatives of the virtual controller. Furthermore, to achieve timely system response, an input delay auxiliary system (IDAS) is introduced to effectively compensate the delayed signal between control commands and actuators. A concise adaptive law is developed to eliminate the negative impact induced by system uncertainty and ocean disturbance. Through the Lyapunov stability analysis, all tracking errors of the closed-loop system are converged to the neighborhood of origin within fixed-time setting. Finally, the effectiveness and superiority of the proposed controller is exemplified by numerical simulations.
{"title":"Adaptive fixed-time dynamic surface path following control for underactuated ships with input delay","authors":"Chenfeng Huang , Kaiyue Zhou , Kailu Zhou , Zuojing Su","doi":"10.1016/j.ijnaoe.2025.100691","DOIUrl":"10.1016/j.ijnaoe.2025.100691","url":null,"abstract":"<div><div>This paper proposes a novel fixed-time path-following control strategy for underactuated ships with input delay. Firstly, the fractional power is employed in the controller design to obtain the fast system convergence. Then, a fixed-time dynamic surface control (FTDSC) technique is presented to approximate the analytic derivatives of the virtual controller. Furthermore, to achieve timely system response, an input delay auxiliary system (IDAS) is introduced to effectively compensate the delayed signal between control commands and actuators. A concise adaptive law is developed to eliminate the negative impact induced by system uncertainty and ocean disturbance. Through the Lyapunov stability analysis, all tracking errors of the closed-loop system are converged to the neighborhood of origin within fixed-time setting. Finally, the effectiveness and superiority of the proposed controller is exemplified by numerical simulations.</div></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"17 ","pages":"Article 100691"},"PeriodicalIF":3.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145463083","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}
Pub Date : 2025-01-01DOI: 10.1016/j.ijnaoe.2025.100705
In-Chang Yeo , Myung-Il Roh , Yun-Sik Kim , Ha-Yun Kim , Do-Hyeok Ahn , Nam-Sun Son
Conventional methods for localizing nearby other ships using multiple sensors have faced limitations in practical applicability in real maritime environments due to high costs and environmental constraints. To address this, the present study proposed a method that accurately localizes other ships using only a camera. First, a virtual maritime environment was constructed to precisely replicate a real maritime environment, enabling efficient reproduction of diverse maritime scenarios and the generation of a large-scale dataset through automatic data labeling. Based on this dataset, we trained MonoLSS (Mono-Learnable Sample Selection), an image-based 3D object detection model, and used it to localize other ships. To evaluate the performance of the proposed method, we compared it with existing horizon-based and depth-based methods for localization across five representative scenarios: head-on, following, crossing with a single ship, crossing with multiple ships, and heavy storm. The results show that the proposed method achieved MAEs of 2.39 m, 2.20 m, 2.09 m, and 2.31/2.66 m (for each ship in the crossing scenario), and 3.28 m across the five scenarios. These results correspond to an error reduction of up to 92.03 % compared with conventional methods. The results demonstrate that the proposed method enables robust, real-time localization of other ships using a single camera, regardless of environmental conditions. Therefore, it is expected to make a significant contribution to the realization of safe autonomous navigation in real maritime environments where the use of additional sensors is limited.
{"title":"A localization method of nearby ships based on 3D object detection using a camera","authors":"In-Chang Yeo , Myung-Il Roh , Yun-Sik Kim , Ha-Yun Kim , Do-Hyeok Ahn , Nam-Sun Son","doi":"10.1016/j.ijnaoe.2025.100705","DOIUrl":"10.1016/j.ijnaoe.2025.100705","url":null,"abstract":"<div><div>Conventional methods for localizing nearby other ships using multiple sensors have faced limitations in practical applicability in real maritime environments due to high costs and environmental constraints. To address this, the present study proposed a method that accurately localizes other ships using only a camera. First, a virtual maritime environment was constructed to precisely replicate a real maritime environment, enabling efficient reproduction of diverse maritime scenarios and the generation of a large-scale dataset through automatic data labeling. Based on this dataset, we trained MonoLSS (Mono-Learnable Sample Selection), an image-based 3D object detection model, and used it to localize other ships. To evaluate the performance of the proposed method, we compared it with existing horizon-based and depth-based methods for localization across five representative scenarios: head-on, following, crossing with a single ship, crossing with multiple ships, and heavy storm. The results show that the proposed method achieved MAEs of 2.39 m, 2.20 m, 2.09 m, and 2.31/2.66 m (for each ship in the crossing scenario), and 3.28 m across the five scenarios. These results correspond to an error reduction of up to 92.03 % compared with conventional methods. The results demonstrate that the proposed method enables robust, real-time localization of other ships using a single camera, regardless of environmental conditions. Therefore, it is expected to make a significant contribution to the realization of safe autonomous navigation in real maritime environments where the use of additional sensors is limited.</div></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"17 ","pages":"Article 100705"},"PeriodicalIF":3.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145568259","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}
Pub Date : 2025-01-01DOI: 10.1016/j.ijnaoe.2025.100704
Kyeonguk Heo, Dong-Min Park, Dongho Jung
This study experimentally investigates wave elevations induced by gap flow when floating bodies are positioned near a quay wall. Two-dimensional wave flume tests were conducted with models of uniform breadth, considering the number of floating bodies, hull geometry, and quay–ship gap distance as independent variables, while water depth and breadth were fixed. Incident wave amplitudes of 1.5 cm and 2.5 cm and a wide range of wave periods were applied. The results confirmed that piston-mode resonance occurs under both single- and two-body conditions. For the single-body case, the resonance frequency shifted to higher values as the quay–ship gap narrowed, with midship sections showing stronger responses than rectangular sections. A similar trend was observed for the two-body case, where resonance appeared not only between the quay and ship but also between the two ships. The resonance frequency in both gaps shifted to higher values as the gap distance decreased, and dual peaks were observed due to the coexistence of two resonance modes. The response amplitude was again more pronounced for midship sections. These findings enhance the understanding of gap flow in simultaneous bunkering scenarios and provide reliable experimental data for validating numerical simulations and assessing mooring safety.
{"title":"An experimental study on the gap flow of floating bodies near a quay wall","authors":"Kyeonguk Heo, Dong-Min Park, Dongho Jung","doi":"10.1016/j.ijnaoe.2025.100704","DOIUrl":"10.1016/j.ijnaoe.2025.100704","url":null,"abstract":"<div><div>This study experimentally investigates wave elevations induced by gap flow when floating bodies are positioned near a quay wall. Two-dimensional wave flume tests were conducted with models of uniform breadth, considering the number of floating bodies, hull geometry, and quay–ship gap distance as independent variables, while water depth and breadth were fixed. Incident wave amplitudes of 1.5 cm and 2.5 cm and a wide range of wave periods were applied. The results confirmed that piston-mode resonance occurs under both single- and two-body conditions. For the single-body case, the resonance frequency shifted to higher values as the quay–ship gap narrowed, with midship sections showing stronger responses than rectangular sections. A similar trend was observed for the two-body case, where resonance appeared not only between the quay and ship but also between the two ships. The resonance frequency in both gaps shifted to higher values as the gap distance decreased, and dual peaks were observed due to the coexistence of two resonance modes. The response amplitude was again more pronounced for midship sections. These findings enhance the understanding of gap flow in simultaneous bunkering scenarios and provide reliable experimental data for validating numerical simulations and assessing mooring safety.</div></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"17 ","pages":"Article 100704"},"PeriodicalIF":3.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145568260","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}
Pub Date : 2025-01-01DOI: 10.1016/j.ijnaoe.2025.100672
Jing Chen , Mingjiu Yu , Weilan An , Qiuyuan Zhu , Hao Fan
Confined spaces in submarines pose a serious barrier to crew operations and mobility. To enhance internal passage efficiency in submarines, this study proposed the Passage Efficiency Driven Layout Optimization Strategy (PEDLOS), which considers passage capacity as a key factor. Congestion risks were identified using a passage simulation of the current simulated layout. After building a network of passage nodes, the shortest path matrix was computed by Dijkstra's algorithm, which also involved passage coefficients for revision. An optimal layout scheme that balanced circulation passage efficiency, adjacency, and circulation requirements was subsequently produced by multi-objective optimization based on genetic algorithm. The PEDLOS could provide an innovative approach to enhance internal passage efficiency and overcome the limitations of current layout methods that unduly rely on expert experience and overlook passage capacity drivers. The study provides theoretical and practical support for confined space design by incorporation of passage capacity as a major optimization indicator.
{"title":"Enhancing passage efficiency in cabin spaces: A layout optimization approach for submarine integrating intelligent algorithms and passage capacity","authors":"Jing Chen , Mingjiu Yu , Weilan An , Qiuyuan Zhu , Hao Fan","doi":"10.1016/j.ijnaoe.2025.100672","DOIUrl":"10.1016/j.ijnaoe.2025.100672","url":null,"abstract":"<div><div>Confined spaces in submarines pose a serious barrier to crew operations and mobility. To enhance internal passage efficiency in submarines, this study proposed the Passage Efficiency Driven Layout Optimization Strategy (PEDLOS), which considers passage capacity as a key factor. Congestion risks were identified using a passage simulation of the current simulated layout. After building a network of passage nodes, the shortest path matrix was computed by Dijkstra's algorithm, which also involved passage coefficients for revision. An optimal layout scheme that balanced circulation passage efficiency, adjacency, and circulation requirements was subsequently produced by multi-objective optimization based on genetic algorithm. The PEDLOS could provide an innovative approach to enhance internal passage efficiency and overcome the limitations of current layout methods that unduly rely on expert experience and overlook passage capacity drivers. The study provides theoretical and practical support for confined space design by incorporation of passage capacity as a major optimization indicator.</div></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"17 ","pages":"Article 100672"},"PeriodicalIF":3.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144720898","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}
Pub Date : 2025-01-01DOI: 10.1016/j.ijnaoe.2025.100708
Si-Won Kim , Geon-Woo Kim , Jung-Hyeon Kim , Sun-Hyuck Im , Seong-Hyeon Jeong , Jin-Hyeok Seo , Yeon-Su Kim , Jong-Yong Park
With the growing deployment of multi-USV (unmanned surface vehicle) systems for complex maritime operations, coordinated path planning is critical for safety and efficiency in congested waterways. Classical multi-agent path finding (MAPF) methods, however, often neglect vessel kinematics and collision envelopes, yielding trajectories that are impractical or unsafe at sea. We present a centralized planning framework based on any-angle Safe Interval Path Planning (AA-SIPP) augmented with a vessel-specific maximum yaw-rate constraint. This yields smooth, kinematically feasible trajectories while preserving continuous-time separation. The approach is validated in high-fidelity Gazebo marina simulations involving up to 20 USVs based on the WAM-V platform. Compared with Conflict-Based Search (CBS), a representative grid-based MAPF algorithm, our framework maintained the prescribed safety distances and achieved zero collisions across all scenarios considered, whereas CBS exhibited separation violations in simulation. The method also scales well: mission makespan remained nearly constant as fleet size increased. These results support the applicability of dynamically constrained MAPF to maritime coordination in congested environments.
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