Pub Date : 2026-01-01Epub Date: 2026-01-16DOI: 10.1016/j.ijnaoe.2026.100740
Seungtae Kim , Youngjun You , Sunkyu Lee
Underwater vehicles have been recognized as a key strategic asset due to the increasing uncertainty of international situations and national security. For their design and construction, it is necessary to develop preliminary design approaches to determine the volumes and longitudinal locations of the tanks while considering the minimum design requirements. A multi-objective optimization technique was applied for optimization of the volumes and longitudinal locations. A concept desgn procedure was constructed to determine volumes and longitudinal locations of trim and compensation tanks. The feasibility of designed tanks was assessed after verifying in-house code for evaluating the trim-compensation polygon. The design variables, constraints, and objective functions were formulated to define an optimization problem using NSGA-Ⅱ. The feasibility of the constructed approach was reviewed through a comparative study considering different constraints. The applicability of the constructed approach was confirmed by investigating the effect of requested number of trim and compensation tanks.
{"title":"Optimization of volumes and longitudinal locations of trim and compensation tanks for underwater vehicles using non-dominated sorting genetic algorithm Ⅱ","authors":"Seungtae Kim , Youngjun You , Sunkyu Lee","doi":"10.1016/j.ijnaoe.2026.100740","DOIUrl":"10.1016/j.ijnaoe.2026.100740","url":null,"abstract":"<div><div>Underwater vehicles have been recognized as a key strategic asset due to the increasing uncertainty of international situations and national security. For their design and construction, it is necessary to develop preliminary design approaches to determine the volumes and longitudinal locations of the tanks while considering the minimum design requirements. A multi-objective optimization technique was applied for optimization of the volumes and longitudinal locations. A concept desgn procedure was constructed to determine volumes and longitudinal locations of trim and compensation tanks. The feasibility of designed tanks was assessed after verifying in-house code for evaluating the trim-compensation polygon. The design variables, constraints, and objective functions were formulated to define an optimization problem using NSGA-Ⅱ. The feasibility of the constructed approach was reviewed through a comparative study considering different constraints. The applicability of the constructed approach was confirmed by investigating the effect of requested number of trim and compensation tanks.</div></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"18 ","pages":"Article 100740"},"PeriodicalIF":3.9,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147396765","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 : 2026-01-01Epub Date: 2025-11-06DOI: 10.1016/j.ijnaoe.2025.100702
Changhun Lee , Hyeri Lee , I Ketut Aria Pria Utama , Woochan Seok
This study presents a comparative computational analysis of the hydrodynamic flow characteristics around the Joubert BB2 submarine using Reynolds-Averaged Navier–Stokes (RANS) and Partially-Averaged Navier–Stokes (PANS) turbulence models. Simulations were performed under two representative operating conditions: straight-ahead motion and 10° drift. The numerical framework was validated against MARIN benchmark data, focusing on the total resistance and axial velocity distributions at the propeller plane. Comparative analyses demonstrated that the PANS model better captures the spatial development of turbulent kinetic energy, along with asymmetric wake features and intricate vortex interactions. The analysis included detailed comparisons of wall shear stress, axial velocity, vorticity, vortex structure and turbulent kinetic energy distributions. In particular, the PANS model demonstrated superior capability in capturing flow separation, vortex development, and wake evolution under asymmetric inflow conditions. Under both conditions, the PANS model captured more coherent vortex structures and more pronounced variations in velocity, while the RANS model exhibited overpredicted turbulence energy and more diffused wake characteristics. These findings suggest that the PANS model offers a physically consistent and computationally efficient alternative to RANS for simulating unsteady and asymmetric flows around submerged bodies, particularly in scenarios where wake dynamics critically influence propulsion and maneuvering performance.
本文采用reynolds - average Navier-Stokes （RANS）和部分平均Navier-Stokes （PANS）湍流模型对Joubert BB2潜艇周围的水动力流动特性进行了对比计算分析。在两种典型工况下进行了仿真：直线运动和10°漂移。针对MARIN基准数据对数值框架进行了验证，重点研究了螺旋桨平面的总阻力和轴向速度分布。对比分析表明，PANS模型更好地捕捉了湍流动能的空间发展，以及不对称尾迹特征和复杂的涡相互作用。分析包括壁面剪应力、轴向速度、涡量、涡结构和湍流动能分布的详细比较。特别是，在非对称入流条件下，PANS模型在捕捉流动分离、涡发展和尾迹演变方面表现出了优越的能力。在这两种情况下，PANS模型捕捉到了更连贯的涡结构和更明显的速度变化，而RANS模型则表现出湍流能量的高估和更扩散的尾迹特征。这些发现表明，PANS模型为模拟水下物体周围的非定常和非对称流动提供了一种物理上一致且计算效率高的替代方案，特别是在尾流动力学严重影响推进和机动性能的情况下。
{"title":"Comparative study on the hydrodynamic flow characteristics around the BB2 submarine using RANS and PANS turbulence models under straight and drift conditions","authors":"Changhun Lee , Hyeri Lee , I Ketut Aria Pria Utama , Woochan Seok","doi":"10.1016/j.ijnaoe.2025.100702","DOIUrl":"10.1016/j.ijnaoe.2025.100702","url":null,"abstract":"<div><div>This study presents a comparative computational analysis of the hydrodynamic flow characteristics around the Joubert BB2 submarine using Reynolds-Averaged Navier–Stokes (RANS) and Partially-Averaged Navier–Stokes (PANS) turbulence models. Simulations were performed under two representative operating conditions: straight-ahead motion and 10° drift. The numerical framework was validated against MARIN benchmark data, focusing on the total resistance and axial velocity distributions at the propeller plane. Comparative analyses demonstrated that the PANS model better captures the spatial development of turbulent kinetic energy, along with asymmetric wake features and intricate vortex interactions. The analysis included detailed comparisons of wall shear stress, axial velocity, vorticity, vortex structure and turbulent kinetic energy distributions. In particular, the PANS model demonstrated superior capability in capturing flow separation, vortex development, and wake evolution under asymmetric inflow conditions. Under both conditions, the PANS model captured more coherent vortex structures and more pronounced variations in velocity, while the RANS model exhibited overpredicted turbulence energy and more diffused wake characteristics. These findings suggest that the PANS model offers a physically consistent and computationally efficient alternative to RANS for simulating unsteady and asymmetric flows around submerged bodies, particularly in scenarios where wake dynamics critically influence propulsion and maneuvering performance.</div></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"18 ","pages":"Article 100702"},"PeriodicalIF":3.9,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145973262","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 : 2026-01-01Epub Date: 2025-12-08DOI: 10.1016/j.ijnaoe.2025.100716
Pardeep Pankaj , Dave Kim , Daseul Jeong , Chunsik Shim
This study numerically investigates a cold expansion (CE) based insert installation for repairing 7075-T6 aluminum holes. A 3D elasto-plastic finite element model combined with response surface methodology examines three factors: the CE%, insert thickness (IT), and edge margin ratio (EMR), and their effects on mandrel force, residual stresses, and crack initiation cycles. Compressive hoop residual stress near the bore deepens from CE = 1 %–3 % and then saturates, while tensile residual stress at the free edge increases with higher CE and lower EMR. Fatigue crack initiation shifts from the hole entry at CE = 1 % to the free edge at CE ≥ 3 % due to the free edge tension. The highest initiation cycles are achieved with the process condition at CE = 3 %, IT = 0.254 mm, and EMR = 1.7. These results provide the range of process variables required to repair corroded aluminum holes using cold-expanded inserts.
本研究对7075-T6铝孔的冷扩镶件修复进行了数值研究。结合响应面方法的三维弹塑性有限元模型考察了三个因素：CE%、嵌件厚度（IT）和边缘比（EMR），以及它们对心轴力、残余应力和裂纹萌生周期的影响。孔附近的压环残余应力在CE = 1% ~ 3%时逐渐加深，然后趋于饱和，而自由边缘的拉残余应力则随着CE的增大和EMR的降低而增大。当CE = 1%时，由于自由边缘张力的作用，疲劳裂纹的起裂从孔口处转移到CE≥3%时的自由边缘处。在CE = 3%, IT = 0.254 mm, EMR = 1.7的工艺条件下，获得了最高的起始周期。这些结果提供了使用冷膨胀刀片修复腐蚀铝孔所需的工艺变量范围。
{"title":"A comprehensive finite element study of cold expanded insert installation for the corrosion repair of 7075-T6 aluminum alloy holes","authors":"Pardeep Pankaj , Dave Kim , Daseul Jeong , Chunsik Shim","doi":"10.1016/j.ijnaoe.2025.100716","DOIUrl":"10.1016/j.ijnaoe.2025.100716","url":null,"abstract":"<div><div>This study numerically investigates a cold expansion (CE) based insert installation for repairing 7075-T6 aluminum holes. A 3D elasto-plastic finite element model combined with response surface methodology examines three factors: the CE%, insert thickness (IT), and edge margin ratio (EMR), and their effects on mandrel force, residual stresses, and crack initiation cycles. Compressive hoop residual stress near the bore deepens from CE = 1 %–3 % and then saturates, while tensile residual stress at the free edge increases with higher CE and lower EMR. Fatigue crack initiation shifts from the hole entry at CE = 1 % to the free edge at CE ≥ 3 % due to the free edge tension. The highest initiation cycles are achieved with the process condition at CE = 3 %, IT = 0.254 mm, and EMR = 1.7. These results provide the range of process variables required to repair corroded aluminum holes using cold-expanded inserts.</div></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"18 ","pages":"Article 100716"},"PeriodicalIF":3.9,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145838033","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 : 2026-01-01Epub Date: 2025-12-13DOI: 10.1016/j.ijnaoe.2025.100729
Myeong-Min Kim , Kwang-Jun Paik , Soon-Hyun Lee , Jae-Hyeon An , Soo-Yeon Kwon
This study evaluated the self-propulsion performance of the K-Supramax (66,000 DWT) bulk carrier in calm water and regular wave conditions at the design speed (14.5 knots) and 4.0 knots. Using the virtual disk method in Computational Fluid Dynamics (CFD) analysis, the self-propulsion characteristics were validated based on KRISO's experimental data, and these characteristics were applied to analyze the self-propulsion performance under wave conditions. Major self-propulsion factors, such as the thrust deduction factor and effective wake fraction, were analyzed to examine the impact of wave conditions on propulsion efficiency. Additionally, the differences in the delivered power (DHP) estimated by the CFD simulation and the load variation method were analyzed according to wave conditions. This research identified the impact of added resistance due to waves on self-propulsion performance, demonstrating that the effect of added resistance was more significant at 4.0 knots than at 14.5 knots. This study provides fundamental data for analyzing self-propulsion performance under wave conditions and establishes an important foundation for future research on estimating the minimum propulsion power under both design and low-speed conditions.
{"title":"A numerical study on self-propulsion performance of the 66k DWT bulk carrier in low-speed calm water and regular wave conditions","authors":"Myeong-Min Kim , Kwang-Jun Paik , Soon-Hyun Lee , Jae-Hyeon An , Soo-Yeon Kwon","doi":"10.1016/j.ijnaoe.2025.100729","DOIUrl":"10.1016/j.ijnaoe.2025.100729","url":null,"abstract":"<div><div>This study evaluated the self-propulsion performance of the K-Supramax (66,000 DWT) bulk carrier in calm water and regular wave conditions at the design speed (14.5 knots) and 4.0 knots. Using the virtual disk method in Computational Fluid Dynamics (CFD) analysis, the self-propulsion characteristics were validated based on KRISO's experimental data, and these characteristics were applied to analyze the self-propulsion performance under wave conditions. Major self-propulsion factors, such as the thrust deduction factor and effective wake fraction, were analyzed to examine the impact of wave conditions on propulsion efficiency. Additionally, the differences in the delivered power (DHP) estimated by the CFD simulation and the load variation method were analyzed according to wave conditions. This research identified the impact of added resistance due to waves on self-propulsion performance, demonstrating that the effect of added resistance was more significant at 4.0 knots than at 14.5 knots. This study provides fundamental data for analyzing self-propulsion performance under wave conditions and establishes an important foundation for future research on estimating the minimum propulsion power under both design and low-speed conditions.</div></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"18 ","pages":"Article 100729"},"PeriodicalIF":3.9,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145921871","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 : 2026-01-01Epub Date: 2025-12-20DOI: 10.1016/j.ijnaoe.2025.100732
Dayeon Jeong , Min-Jae Oh , Jinyoung Park
Classification societies perform stability analysis based on offsets submitted by shipyards and verify the results. However, in many practical situations, the hull form data required for hydrostatic evaluation is insufficient. This commonly occurs during the stability reassessment of retrofitted or damaged ships, or when original design data are limited due to confidentiality or unavailable from foreign shipyards. As a result, classification societies are often required to reconstruct the hull form using only partial information. To address this issue this study proposes a reverse-engineering method that regenerates hull forms by introducing a novel interpolation approach with area constraints so that hydrostatic requirements are inherently satisfied. Specifically, waterlines are generated at each draft level with their area constrained to match the and this guarantees the correct displacement. By maintaining waterline consistency across drafts additional hydrostatic constraints such as the , , are simultaneously satisfied. This mathematically grounded perspective that treats the -based area as a governing constraint provides a new way to couple hydrostatic data with geometric reconstruction and move beyond manual adjustments. The proposed method was validated on three ship types, and the results demonstrated its effectiveness in producing reliable hull forms for performance analysis while significantly reducing both time and dependency on expert judgment.
{"title":"Hull form reconstruction from insufficient data conforming to hydrostatic constraints","authors":"Dayeon Jeong , Min-Jae Oh , Jinyoung Park","doi":"10.1016/j.ijnaoe.2025.100732","DOIUrl":"10.1016/j.ijnaoe.2025.100732","url":null,"abstract":"<div><div>Classification societies perform stability analysis based on offsets submitted by shipyards and verify the results. However, in many practical situations, the hull form data required for hydrostatic evaluation is insufficient. This commonly occurs during the stability reassessment of retrofitted or damaged ships, or when original design data are limited due to confidentiality or unavailable from foreign shipyards. As a result, classification societies are often required to reconstruct the hull form using only partial information. To address this issue this study proposes a reverse-engineering method that regenerates hull forms by introducing a novel interpolation approach with area constraints so that hydrostatic requirements are inherently satisfied. Specifically, waterlines are generated at each draft level with their area constrained to match the <span><math><mrow><msub><mi>C</mi><mrow><mi>W</mi><mi>P</mi></mrow></msub></mrow></math></span> and this guarantees the correct displacement. By maintaining waterline consistency across drafts additional hydrostatic constraints such as the <span><math><mrow><msub><mi>C</mi><mi>P</mi></msub></mrow></math></span>, <span><math><mrow><mi>L</mi><mi>C</mi><mi>B</mi></mrow></math></span>, <span><math><mrow><mi>V</mi><mi>C</mi><mi>B</mi></mrow></math></span> are simultaneously satisfied. This mathematically grounded perspective that treats the <span><math><mrow><msub><mi>C</mi><mrow><mi>W</mi><mi>P</mi></mrow></msub></mrow></math></span>-based area as a governing constraint provides a new way to couple hydrostatic data with geometric reconstruction and move beyond manual adjustments. The proposed method was validated on three ship types, and the results demonstrated its effectiveness in producing reliable hull forms for performance analysis while significantly reducing both time and dependency on expert judgment.</div></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"18 ","pages":"Article 100732"},"PeriodicalIF":3.9,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145921873","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 : 2026-01-01Epub Date: 2025-12-16DOI: 10.1016/j.ijnaoe.2025.100730
Jiang Xu , Jun Guo , Huaxun Zhao , Wenbo Zhang
Dynamic stress response is an important parameter to describe the degree of impact damage of a structure under underwater explosion and able to act as a significant reference for structural safety assessment. However, the dynamic response of a structure presents a strongly nonlinear process, and for large underwater engineering structures, it is difficult to accurately obtain analytic solutions in the whole frequency range simply through theoretical analysis methods. From a statistical perspective, this paper systematically describes and derives the impact input and dissipation process in the form of energy. Within the linear elasticity, the connection between structural strain and energy is derived from the energy density relationship during the process of structural vibration, achieving the prediction of structural stress. The critical input of the system under the critical elasticity is inversely derived based on the structure’s yield strength, which provides a technical reference for the safety assessment of large underwater structures under impact. After verifying by underwater explosion experiments, the relative error obtained through the prediction method and experiments is within 17 %, with an average error of 7.52 %.
{"title":"High-frequency stress prediction and safety assessment method for structures under the effect of underwater explosions","authors":"Jiang Xu , Jun Guo , Huaxun Zhao , Wenbo Zhang","doi":"10.1016/j.ijnaoe.2025.100730","DOIUrl":"10.1016/j.ijnaoe.2025.100730","url":null,"abstract":"<div><div>Dynamic stress response is an important parameter to describe the degree of impact damage of a structure under underwater explosion and able to act as a significant reference for structural safety assessment. However, the dynamic response of a structure presents a strongly nonlinear process, and for large underwater engineering structures, it is difficult to accurately obtain analytic solutions in the whole frequency range simply through theoretical analysis methods. From a statistical perspective, this paper systematically describes and derives the impact input and dissipation process in the form of energy. Within the linear elasticity, the connection between structural strain and energy is derived from the energy density relationship during the process of structural vibration, achieving the prediction of structural stress. The critical input of the system under the critical elasticity is inversely derived based on the structure’s yield strength, which provides a technical reference for the safety assessment of large underwater structures under impact. After verifying by underwater explosion experiments, the relative error obtained through the prediction method and experiments is within 17 %, with an average error of 7.52 %.</div></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"18 ","pages":"Article 100730"},"PeriodicalIF":3.9,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145837963","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 : 2026-01-01Epub Date: 2025-12-04DOI: 10.1016/j.ijnaoe.2025.100714
Youjia Han , Huibin Wang
With single Unmanned Surface Vehicle (USV) no longer meeting growing mission demands, cooperative multi-USV systems have become essential, particularly in obstacle-rich waters where task allocation deviates and path planning struggles to balance distance and safety. To address these challenges, an integrated framework combining a constrained-distance-based Hungarian assignment algorithm and an improved Hippopotamus Optimization algorithm (CDH-IHO) is developed to achieve simultaneous target assignment and path planning (STAPP). The CDH module achieves globally optimal assignment by exploiting a constrained distance matrix constructed through the Fast Sweeping Method (FSM), while the IHO module introduces a Cubic chaotic map and a mutation operator to enhance convergence and avoid local optima. Distance, turning angle, safety, and penalty terms are jointly considered for collision-free path generation. Simulations in five scenarios verify global optimality in assignment and superior performance in path length, smoothness, and safety. CDH-IHO provides an efficient and robust solution for STAPP.
{"title":"Multi-USV cooperative path planning via FSM-based distance field and enhanced hippopotamus optimization","authors":"Youjia Han , Huibin Wang","doi":"10.1016/j.ijnaoe.2025.100714","DOIUrl":"10.1016/j.ijnaoe.2025.100714","url":null,"abstract":"<div><div>With single Unmanned Surface Vehicle (USV) no longer meeting growing mission demands, cooperative multi-USV systems have become essential, particularly in obstacle-rich waters where task allocation deviates and path planning struggles to balance distance and safety. To address these challenges, an integrated framework combining a constrained-distance-based Hungarian assignment algorithm and an improved Hippopotamus Optimization algorithm (CDH-IHO) is developed to achieve simultaneous target assignment and path planning (STAPP). The CDH module achieves globally optimal assignment by exploiting a constrained distance matrix constructed through the Fast Sweeping Method (FSM), while the IHO module introduces a Cubic chaotic map and a mutation operator to enhance convergence and avoid local optima. Distance, turning angle, safety, and penalty terms are jointly considered for collision-free path generation. Simulations in five scenarios verify global optimality in assignment and superior performance in path length, smoothness, and safety. CDH-IHO provides an efficient and robust solution for STAPP.</div></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"18 ","pages":"Article 100714"},"PeriodicalIF":3.9,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145789181","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 : 2026-01-01Epub Date: 2025-12-02DOI: 10.1016/j.ijnaoe.2025.100713
Hyun Soo Kim , Myung-Il Roh
The utilization of natural gas is expanding as part of efforts to reduce greenhouse gas (GHG) emissions. Natural gas is typically liquefied at cryogenic temperatures in order to enhance the efficiency of maritime transport. When these cryogenic cargoes are shipped, BOG (Boil-Off Gas) is generated by the external heat and wave-induced ship motion. Proper management of BOG is critical to maintaining the cargo tank pressure within a safe operational range. In the case of LNG (Liquefied Natural Gas) carriers, BOG is used as fuel for main engines and generator engines, with any surplus being burned in the GCU (Gas Combustion Unit) or reliquefied by a reliquefaction system. Accurate prediction of BOG generation and cargo tank pressure is therefore essential for optimizing reliquefaction system operations and voyage planning. Although various experimental and CFD-based studies have been conducted, it remains challenging to capture the complex, irregular characteristics of real marine environments, particularly the effects of ship motion and sloshing. This study presents a framework for developing a data-driven model that predicts cargo tank pressure in LNG carriers. The data-driven model is based on long-term operation data from a 174K-class LNG carrier, enabling consideration of the combined effects of BOG consumption, reliquefaction performance, and marine environmental conditions on cargo tank pressure. The variables related to cargo tank pressure are derived from ship operation, BOG consumption, and marine environmental conditions. Several regression and machine learning algorithms were compared to identify the most effective predictive model. The model's accuracy was verified by comparing predicted values with actual measurements from an LNG carrier that had been in operation for 2 years, and the results confirmed high predictive accuracy. This approach provides a practical framework for data-driven cargo tank pressure prediction and contributes to improving energy efficiency and reducing GHG emissions in LNG carrier operations.
{"title":"Data-driven model for predicting cargo tank pressure of an LNG carrier considering environmental effects","authors":"Hyun Soo Kim , Myung-Il Roh","doi":"10.1016/j.ijnaoe.2025.100713","DOIUrl":"10.1016/j.ijnaoe.2025.100713","url":null,"abstract":"<div><div>The utilization of natural gas is expanding as part of efforts to reduce greenhouse gas (GHG) emissions. Natural gas is typically liquefied at cryogenic temperatures in order to enhance the efficiency of maritime transport. When these cryogenic cargoes are shipped, BOG (Boil-Off Gas) is generated by the external heat and wave-induced ship motion. Proper management of BOG is critical to maintaining the cargo tank pressure within a safe operational range. In the case of LNG (Liquefied Natural Gas) carriers, BOG is used as fuel for main engines and generator engines, with any surplus being burned in the GCU (Gas Combustion Unit) or reliquefied by a reliquefaction system. Accurate prediction of BOG generation and cargo tank pressure is therefore essential for optimizing reliquefaction system operations and voyage planning. Although various experimental and CFD-based studies have been conducted, it remains challenging to capture the complex, irregular characteristics of real marine environments, particularly the effects of ship motion and sloshing. This study presents a framework for developing a data-driven model that predicts cargo tank pressure in LNG carriers. The data-driven model is based on long-term operation data from a 174K-class LNG carrier, enabling consideration of the combined effects of BOG consumption, reliquefaction performance, and marine environmental conditions on cargo tank pressure. The variables related to cargo tank pressure are derived from ship operation, BOG consumption, and marine environmental conditions. Several regression and machine learning algorithms were compared to identify the most effective predictive model. The model's accuracy was verified by comparing predicted values with actual measurements from an LNG carrier that had been in operation for 2 years, and the results confirmed high predictive accuracy. This approach provides a practical framework for data-driven cargo tank pressure prediction and contributes to improving energy efficiency and reducing GHG emissions in LNG carrier operations.</div></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"18 ","pages":"Article 100713"},"PeriodicalIF":3.9,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145735924","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 : 2026-01-01Epub Date: 2026-02-21DOI: 10.1016/j.ijnaoe.2026.100753
Bo Wen, Zhibin Li, Siyu Chen, Cheng Zhang
The aircraft carrier flight deck is a core area for naval aviation operations, where personnel are exposed to multiple threats such as blast waves, fragments, and thermal damage during high-intensity combat. The coupling between personnel survivability and deck-operations efficiency directly determines the sortie rate of carrier-based aircraft and the overall combat capability of the fleet. This study proposes a multi-scale coupled assessment model that integrates deck functional zoning and personnel distribution modeling, multi-physical damage mechanisms, and spatiotemporal damage propagation. The deck is discretized into a number of elements to establish a "personnel-task-space" mapping relationship. By integrating multi-physical damage mechanisms and combining the Probit model with Monte Carlo random sampling, a spatiotemporal dynamic assessment of personnel damage is achieved. Principal component analysis is employed to identify high-risk positions and damage hotspots, providing theoretical and methodological support for enhancing the resilience assessment and scheduling optimization of deck operations in damage-prone environments.
{"title":"Method for damage effectiveness assessment of aircraft carrier deck operating personnel","authors":"Bo Wen, Zhibin Li, Siyu Chen, Cheng Zhang","doi":"10.1016/j.ijnaoe.2026.100753","DOIUrl":"10.1016/j.ijnaoe.2026.100753","url":null,"abstract":"<div><div>The aircraft carrier flight deck is a core area for naval aviation operations, where personnel are exposed to multiple threats such as blast waves, fragments, and thermal damage during high-intensity combat. The coupling between personnel survivability and deck-operations efficiency directly determines the sortie rate of carrier-based aircraft and the overall combat capability of the fleet. This study proposes a multi-scale coupled assessment model that integrates deck functional zoning and personnel distribution modeling, multi-physical damage mechanisms, and spatiotemporal damage propagation. The deck is discretized into a number of elements to establish a \"personnel-task-space\" mapping relationship. By integrating multi-physical damage mechanisms and combining the Probit model with Monte Carlo random sampling, a spatiotemporal dynamic assessment of personnel damage is achieved. Principal component analysis is employed to identify high-risk positions and damage hotspots, providing theoretical and methodological support for enhancing the resilience assessment and scheduling optimization of deck operations in damage-prone environments.</div></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"18 ","pages":"Article 100753"},"PeriodicalIF":3.9,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147449206","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 : 2026-01-01Epub Date: 2026-01-22DOI: 10.1016/j.ijnaoe.2026.100747
Gum-jun Son , Joon Bum Kim , Nam-Seon Kang , Sung-Sang Yoo , Sung-Rok Kim
This study proposes a fleet-level integrated cybersecurity monitoring framework to address the maritime industry's digital transformation and rising cyber threats. By analyzing incidents from 2010 to 2020, security requirements tailored to ship operations were derived, leading to a framework that links onboard infrastructure with shore-based security operations centers for real-time monitoring and remote response. The framework enhances threat visibility and response across fleets of multiple vessels. Validation using a ransomware scenario confirmed complete detection of threat events and remote response within an average of 2 min and 11 s. Usability and system stability evaluations further demonstrated applicability in operational environments. These findings verify the feasibility of effective fleet-level monitoring and highlight contributions to cyber resilience and incident response strategies. Future scalability may be achieved through AI-driven threat severity assessment and adaptive policy management, ensuring sustainability and adaptability in evolving maritime contexts.
{"title":"A study on fleet security monitoring framework based on maritime cyber incident response","authors":"Gum-jun Son , Joon Bum Kim , Nam-Seon Kang , Sung-Sang Yoo , Sung-Rok Kim","doi":"10.1016/j.ijnaoe.2026.100747","DOIUrl":"10.1016/j.ijnaoe.2026.100747","url":null,"abstract":"<div><div>This study proposes a fleet-level integrated cybersecurity monitoring framework to address the maritime industry's digital transformation and rising cyber threats. By analyzing incidents from 2010 to 2020, security requirements tailored to ship operations were derived, leading to a framework that links onboard infrastructure with shore-based security operations centers for real-time monitoring and remote response. The framework enhances threat visibility and response across fleets of multiple vessels. Validation using a ransomware scenario confirmed complete detection of threat events and remote response within an average of 2 min and 11 s. Usability and system stability evaluations further demonstrated applicability in operational environments. These findings verify the feasibility of effective fleet-level monitoring and highlight contributions to cyber resilience and incident response strategies. Future scalability may be achieved through AI-driven threat severity assessment and adaptive policy management, ensuring sustainability and adaptability in evolving maritime contexts.</div></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"18 ","pages":"Article 100747"},"PeriodicalIF":3.9,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147396768","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}
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