International Journal of Naval Architecture and Ocean Engineering最新文献

{"title":"An experimental study on the motion-structure coupled characteristics of multi-linked floating unit offshore structure with two different connection conditions","authors":"Kangsu Lee ,&nbsp;Kichan Sim","doi":"10.1016/j.ijnaoe.2024.100614","DOIUrl":"10.1016/j.ijnaoe.2024.100614","url":null,"abstract":"<div><p>With the recent intensification of climate change due to global warming, the importance of renewable energy has been highlighted, emphasizing the need for renewable energy development. In the case of renewable energy power generation, it is installed and operated on a large scale to meet energy demand, economic efficiency, and optimize local resources. Therefore, the number of cases of installation on water and sea with high space utilization is gradually increasing. When operating large-scale power systems, conservative design and review are necessary because damage to the structures can cause cascading failures, leading to major accidents. In particular, for photovoltaic systems, the method of expansion by connecting individual unit structures is commonly used. Therefore, it is necessary to analyze the characteristics of the unit structures and the connection methods. In this study, a fluid-structure coupled analysis was performed on the unit structures of a multi-linked floating offshore structures, which can be large-scale expansion, developed by the Korea Research Institute of Ships and Ocean Engineering. The characteristics were analyzed based on the connection method. The analysis results showed that when the connection method was a hinged condition, the pitch motion increased compared to the fixed condition, but since the peak occurred at a high frequency with a 4-s period, it is advantageous to avoid resonance. In particular, it was confirmed that the maximum stress was reduced by approximately three times, which is beneficial for structural integrity. Additionally, it was found that as the stress distribution moved from the center to the edges, it is also advantageous in terms of maintenance. In addition, the numerical method of the multi-linked floating offshore structures and the characteristics of hinged condition were verified through model tests.</p></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"16 ","pages":"Article 100614"},"PeriodicalIF":2.3,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2092678224000335/pdfft?md5=ebf34e2805fbb616f6f32c57256394b9&pid=1-s2.0-S2092678224000335-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142169085","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":"Research on safety evaluation and weather routing optimization of ship based on roll dynamics and improved A* algorithm","authors":"Zilong Guo ,&nbsp;Mei Hong ,&nbsp;Yongchui Zhang ,&nbsp;Jian Shi ,&nbsp;Longxia Qian ,&nbsp;Hanlin Li","doi":"10.1016/j.ijnaoe.2024.100605","DOIUrl":"10.1016/j.ijnaoe.2024.100605","url":null,"abstract":"<div><p>With the steady growth of international trade, sea transport has become indispensable, leading to an increase in maritime accidents. The sinking of the Russian Black Sea Fleet flagship, the guided missile cruiser “Moskva,” underscores the critical need for enhanced maritime safety. However, the dynamics of ship stability, particularly under transverse wind and wave conditions, remain unclear. We aimed to explore ship navigation safety by using the Moskva incident as a case study. Specifically, our objective was to investigate the influence of wind and waves on ship stability, calculate the capsizing probability of the vessel, and devise a fast and safe return path to port. We conducted a comprehensive review of existing literature on ship stability and path-planning algorithms. Leveraging this knowledge, we established the dynamics equation under transverse wind and wave conditions and integrated risk and vulnerability indicators to obtain a quantitative sea-area risk zoning map. Additionally, we employed the A* algorithm to plan a path under International Maritime Organization rules restrictions. Our findings reveal insights into ship stability dynamics and the importance of considering environmental factors in navigation safety. We calculated the capsizing probability of Moskva and devised a fast and safe return path to port, highlighting the practical application of our methodology. This study contributes to the understanding of ship navigation safety by addressing the knowledge gap in ship stability dynamics. Our findings underscore the significance of considering environmental factors in navigation safety planning. However, limitations exist in terms of data availability and model accuracy. Future research should explore additional factors impacting ship stability and refine path-planning algorithms for enhanced safety.</p></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"16 ","pages":"Article 100605"},"PeriodicalIF":2.3,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2092678224000244/pdfft?md5=78f50c14be213481c96bc258f4167cd8&pid=1-s2.0-S2092678224000244-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141638897","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":"A suggestion for space harmonic injection into motor current to reduce propeller vibration","authors":"Yeojin Hyun ,&nbsp;Kwang-Jun Paik ,&nbsp;Soyoung Sung ,&nbsp;Junghyung Park ,&nbsp;Soon-Hyun Lee ,&nbsp;Jinyeong Park","doi":"10.1016/j.ijnaoe.2024.100618","DOIUrl":"10.1016/j.ijnaoe.2024.100618","url":null,"abstract":"<div><p>Propellers produce fluctuating thrust and torque as they rotate in a non-uniform wake field. They contribute most of the vibration and noise generated by the propeller and can lead to mechanical damage to shafts and bearings. Recently, the demand for electric propulsion ships has increased. As the torque and speed fluctuations are generated in marine propellers, harmonic components in the current and voltage of the propulsion motor occur and lead to increased losses, device degradation, and torque pulsations. In this study, a harmonic injection method is proposed to reduce the impact of motor and mechanical vibration caused by the fluctuating load torque of the propeller. A harmonic component is applied to the current of the motor to generate a motor torque with a different phase of the same magnitude as the variation of the load torque of the motor. In this study, a computational fluid dynamics simulation was performed to obtain the torque of the target vessel, medium range tanker, and a MATLAB Simulink was used to model the motor simulation. It was found that the harmonic injection method can reduce the mechanical torque fluctuation of the motor by 87%.</p></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"16 ","pages":"Article 100618"},"PeriodicalIF":2.3,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2092678224000372/pdfft?md5=8883af03488bec0afe7af9e326a46906&pid=1-s2.0-S2092678224000372-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142239941","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":"A numerical study on the optimization of the slit shape of a jet injection propeller","authors":"Jun-Hee Lee ,&nbsp;Ju-Han Lee ,&nbsp;Myeong-Min Kim ,&nbsp;Dohan Oh ,&nbsp;Kwang-Jun Paik","doi":"10.1016/j.ijnaoe.2023.100578","DOIUrl":"10.1016/j.ijnaoe.2023.100578","url":null,"abstract":"<div><p>The shape of the slit that injects the jet from the surface of the propeller was optimized through numerical computations. The high-pressure drop on the propeller surface caused by jet injection could be improved by modifying the hydrofoil geometry of the propeller. As the cover length increased and the slit was located at the center of the propeller, the volume of jets leading to the trailing edge increased, and the propulsion performance was improved. As the height of the slit increased, the thrust increased due to the Coanda effect, and the torque decreased because of the thrust of the jet. The jet injection pattern differed according to the area of the slit and tunnel, which caused a difference in the propeller performance. The jet pattern changed according to the area of the slit and tunnel, leading to a change in propeller performance. It was effective in improving the efficiency by injecting from as wide an area as possible, and the efficiency was improved by approximately 2 % considering the pump efficiency through optimization of the slit shape.</p></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"16 ","pages":"Article 100578"},"PeriodicalIF":2.2,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2092678223000675/pdfft?md5=8318a7286ca15e40bdb33e1870d13c8f&pid=1-s2.0-S2092678223000675-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139029045","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":"Direct prismatic coefficient variation to hull form surface","authors":"Dayeon Jeong,&nbsp;Min-Jae Oh","doi":"10.1016/j.ijnaoe.2024.100615","DOIUrl":"10.1016/j.ijnaoe.2024.100615","url":null,"abstract":"<div><div>The initial ship design process aims to optimize the hull form to enhance ship efficiency. During this phase, hull form variations are executed based on a reference ship to meet shipowner requirements, such as altering the <span><math><mrow><msub><mi>C</mi><mi>P</mi></msub></mrow></math></span> (prismatic coefficient) to adjust the section lines. Once these variations are made, a surface is generated. However, this iterative process can be time-consuming as the surface creation must be done manually each time. Thus, we propose a method to directly apply <span><math><mrow><msub><mi>C</mi><mi>P</mi></msub></mrow></math></span> variation onto the hull form surface, setting the variated section line as a constraint. In this study, the proposed method is employed to modify the hull form surface to meet <span><math><mrow><msub><mi>C</mi><mi>P</mi></msub></mrow></math></span> requirements. The section lines of the modified surface are then extracted to validate the results. This streamlines in the initial hull form design, reduces the overall design time, and yields high-quality hull form surfaces efficiently.</div></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"16 ","pages":"Article 100615"},"PeriodicalIF":2.3,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142356782","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":"Effects of sampling from a naval destroyer’s operational history on fatigue damage estimation","authors":"Ian Thompson ,&nbsp;Radu Chiritoiu ,&nbsp;Teresa Magoga ,&nbsp;Alysson Mondoro ,&nbsp;Malcolm Smith","doi":"10.1016/j.ijnaoe.2024.100610","DOIUrl":"10.1016/j.ijnaoe.2024.100610","url":null,"abstract":"<div><p>The service history of a naval destroyer, HMCS IROQUOIS, was analyzed to develop an operational profile for structural fatigue assessment. The data from 1972 through 2012 provides insights for developing data sample requirements and wave data collection approaches applicable to other aging vessels. The results show that capturing daily wave data at the recorded position sufficiently describes the encountered seaways. Artificially reducing the data set to represent incomplete hull monitoring or operational data indicates that 5–9 years of wave data were required to limit the damage rate coefficient of variation to within 15%. However, operational changes, such as those observed after this destroyer’s midlife refit, may increase data requirements. Similar requirements for convergence were observed in duration-at-sea data derived from annual days at sea or distance sailed. The findings, consistent across the class and another class of ships, show that results for this ship are not anomalous.</p></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"16 ","pages":"Article 100610"},"PeriodicalIF":2.3,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2092678224000293/pdfft?md5=35769528cd1fd9db478a69f67ec73af8&pid=1-s2.0-S2092678224000293-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142169086","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":"Assessment of ship-block stacking status based on images obtained from drone and geographic information system data","authors":"Young-Soo Han ,&nbsp;Kyungho Lee ,&nbsp;Byeongwook Nam ,&nbsp;Yang Ouk Kim ,&nbsp;Youngsu Kim ,&nbsp;Hyeon-Bin Yeo","doi":"10.1016/j.ijnaoe.2024.100583","DOIUrl":"10.1016/j.ijnaoe.2024.100583","url":null,"abstract":"<div><p>Ships are constructed using the shipbuilding method, which involves several blocks. Every block produced in each unit process features a different production speed depending on the block shape, number of members used, and process complexity. Consequently, the blocks produced in one process is stored in the stockyard for the next process operation. As the number of blocks stacked in the stockyard increases, the movement of the blocks and that of their transporters increase, thus resulting in an increase in operating costs. Hence, we propose a method for monitoring the block storage status based on drone images and shipyard Geographic Information System (GIS) information to support the efficient use of block stockyards. Shipyard GIS information is mapped onto the image acquired from the drone, and the area of the stacked block is detected in the image. The block storage area and storage load factor of the stockyard are calculated using the saved block areas and shipyard GIS information. By evaluating shipyard stockyards, we confirmed the possibility of monitoring the status of shipyard block storage based on drone images and GIS information.</p></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"16 ","pages":"Article 100583"},"PeriodicalIF":2.2,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2092678224000025/pdfft?md5=4c3f071483bb286bbdbc87cfdccecfc3&pid=1-s2.0-S2092678224000025-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139482739","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":"New approaches to assess and improve ship operating performance","authors":"Thai Gia Tran ,&nbsp;Hyun Cheol Kim","doi":"10.1016/j.ijnaoe.2024.100607","DOIUrl":"10.1016/j.ijnaoe.2024.100607","url":null,"abstract":"<div><p>The deterioration in the technical conditions of the main engine, hull, and propeller over time in service is natural and causes adverse effects on ship operating performance, so determining and overcoming this phenomenon is necessary. However, effectively solving this problem is not simple because it is affected by many complex and random factors such as engine deterioration, increased roughness of hull and propeller surfaces, changes in sea state and ship load, etc. In this study, our new approach based on the black-box method and detailed propeller diagrams provides an effective way to assess and improve ship performance both under specific operating conditions and after a period of service. This method was verified and validated with the test data of the Glory Star oil tanker and applied to the Duong River dry cargo ship in Vietnam to determine its performance degradation and provide solutions to overcome this problem. The results showed that after 5 years out of dry dock, the study ship's performance or propulsion efficiency was reduced by about 8.6%, resulting in an increase in fuel consumption of about 6.5% and a decrease in ship speed of about 14.7%. By applying technical solutions such as tuning the engine operating mode and choosing a practical propeller design point, the performance of this ship was greatly improved and brought about high economic and technical efficiency. Especially, the cutting of the propeller edges not only solved the torque-rich phenomena occurring on the study ship's main engine after 5 service years, but also saved 5.1% and 4.9% in hourly fuel consumption, and increased 3.9% and 4.9% in ship speed, calculated for ballast and full load sea trials, respectively.</p></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"16 ","pages":"Article 100607"},"PeriodicalIF":2.3,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2092678224000268/pdfft?md5=2786f4b817f939e20c8f704c8f58cf58&pid=1-s2.0-S2092678224000268-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141698244","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":"Automatic extraction of cable connection information from 2D drawings for electrical outfittings design in shipyards","authors":"Adrian Rahmanto Putra ,&nbsp;Sol Ha ,&nbsp;Kwang-Phil Park","doi":"10.1016/j.ijnaoe.2024.100630","DOIUrl":"10.1016/j.ijnaoe.2024.100630","url":null,"abstract":"<div><div>This study proposes to automate the analysis of wiring diagrams to generate cable lists by using machine learning for text classification and pre-trained Deep Neural Network (DNN)-based image classification to detect cable routes. In shipyards, many drawings are produced for each ship, and analyzing these drawings, especially wiring diagrams, to generate cable lists for the Bill of Materials (BOM) can be a time-consuming and error-prone task. This process is performed manually by reading the cable routes and entering the information into a spreadsheet. To address these challenges, this study aims to automate the information extraction from wiring diagrams. The process involves extracting text from the PDF document and classifying it using machine learning, followed by using DNN-based image classification to trace cable routes and identify the relevant annotations. The developed algorithm was tested on three PDF wiring diagram samples and achieved an average accuracy of about 90%, confirming its effectiveness.</div></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"16 ","pages":"Article 100630"},"PeriodicalIF":2.3,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143142692","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":"AI-enhanced fire detection and suppression system for autonomous ships","authors":"Hyuk Lee ,&nbsp;Jung Hoon Chung ,&nbsp;Hyun Chung ,&nbsp;Jong-Hwan Kim ,&nbsp;Yongho Yoo ,&nbsp;Gil Hyuk Lim ,&nbsp;Won-Sun Ruy","doi":"10.1016/j.ijnaoe.2024.100628","DOIUrl":"10.1016/j.ijnaoe.2024.100628","url":null,"abstract":"<div><div>The rapid propagation of fire after a flashover can result in significant economic losses and human casualties. Meanwhile, the shipping industry faces crew shortages, making unmanned fire detection crucial for reducing manpower while ensuring seamless operations. Although autonomous fire detection and suppression systems (AFDSS) have been applied in tunnels and building infrastructure, no specialized AFDSS exists for unmanned autonomous ships, where minimizing false alarms and ensuring precise fire suppression under irregular wave conditions are critical. In this paper, we introduce an innovative AFDSS that integrates RGB, infrared (IR), and ultraviolet (UV) sensors to reduce false alarms and employ a reinforcement learning algorithm to optimize water spray under sea conditions. We present the design, system integration, and fire-extinguishing experiments, demonstrating the effectiveness of the system in enhancing the fire safety of autonomous ships under simulated sea-state conditions.</div></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"16 ","pages":"Article 100628"},"PeriodicalIF":2.3,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143142690","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}