Abstract This article presents the influence of various ship’s operational conditions occurring during manoeuvres related to entering and leaving the ports and mooring operations. Frequent starts and stops of the ship’s propulsion unit are then required, which affect the variability of the energetic loads of the ship’s power plant, causing accelerated, non-design wear of the ship’s main propulsion engine. The effects of cold start-ups of the main ship engine are the subject of this study. Conditions of the engine inlet valve damage process are discussed. The physics of the degradation process leading to air inlet valve damage was considered. Laboratory tests of structure continuity and their results are discussed, and the valve material defects were excluded as the cause of the damage. The causes of repeated damage to the inlet air valves were identified. The effectiveness of the performed corrective measures was confirmed by a documented control test of the engine start-up. The article is a utilitarian premise for the requirements of the Classification Society.
{"title":"Studies on the Effects of Cold Starts of the Ship Main Engine","authors":"A. Adamkiewicz, J. Fydrych, J. Drzewieniecki","doi":"10.2478/pomr-2022-0031","DOIUrl":"https://doi.org/10.2478/pomr-2022-0031","url":null,"abstract":"Abstract This article presents the influence of various ship’s operational conditions occurring during manoeuvres related to entering and leaving the ports and mooring operations. Frequent starts and stops of the ship’s propulsion unit are then required, which affect the variability of the energetic loads of the ship’s power plant, causing accelerated, non-design wear of the ship’s main propulsion engine. The effects of cold start-ups of the main ship engine are the subject of this study. Conditions of the engine inlet valve damage process are discussed. The physics of the degradation process leading to air inlet valve damage was considered. Laboratory tests of structure continuity and their results are discussed, and the valve material defects were excluded as the cause of the damage. The causes of repeated damage to the inlet air valves were identified. The effectiveness of the performed corrective measures was confirmed by a documented control test of the engine start-up. The article is a utilitarian premise for the requirements of the Classification Society.","PeriodicalId":49681,"journal":{"name":"Polish Maritime Research","volume":"29 1","pages":"109 - 118"},"PeriodicalIF":2.0,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47988305","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}
Viktor Yalama, O. Yakovleva, Volodymyr Trandafilov, M. Khmelniuk
Abstract The study explored the legislative database for the maritime sector to be sustainable and have an intact blue economy. The problem for organizations with shipowners that have fishing boats older than 20 years is stated. Decision-making authorities face challenges nowadays. To be in the fleet for the next decade, shipowners for their ships should deploy energy efficiency projects for marine system retrofitting to improve energy efficiency and meet environmental regulations. The Ship Energy Efficiency Management Plan’s development principles are discussed due to the current need for its deployment from 2021, so shipowners can contribute to the fast adoption of new regulations by the International Maritime Organization. In this work it is being offered to incorporate energy management issues with guidelines for upcoming regulations as well as those that are currently enforced. To improve energy efficiency, reduce environmental impact and cut fuel consumption costs, marine system retrofitting has been proposed. In this paper the focus is being put on studying energy management strengths and weaknesses which can lead to a qualitative understanding of the performance of the organizational structure, this work also focuses on the management settings concerning energy efficiency. If the organization wants to win by integrating energy policy, high-quality communication or promotion of energy efficiency issues should be employed. Marine plastic debris challenges fishing carriers on the African Union route. A possible beneficial solution for shipowners is discussed in this study.
{"title":"Future Sustainable Maritime Sector: Fishing Carriers and their Adoption to the Environmental Regulations. Part I","authors":"Viktor Yalama, O. Yakovleva, Volodymyr Trandafilov, M. Khmelniuk","doi":"10.2478/pomr-2022-0027","DOIUrl":"https://doi.org/10.2478/pomr-2022-0027","url":null,"abstract":"Abstract The study explored the legislative database for the maritime sector to be sustainable and have an intact blue economy. The problem for organizations with shipowners that have fishing boats older than 20 years is stated. Decision-making authorities face challenges nowadays. To be in the fleet for the next decade, shipowners for their ships should deploy energy efficiency projects for marine system retrofitting to improve energy efficiency and meet environmental regulations. The Ship Energy Efficiency Management Plan’s development principles are discussed due to the current need for its deployment from 2021, so shipowners can contribute to the fast adoption of new regulations by the International Maritime Organization. In this work it is being offered to incorporate energy management issues with guidelines for upcoming regulations as well as those that are currently enforced. To improve energy efficiency, reduce environmental impact and cut fuel consumption costs, marine system retrofitting has been proposed. In this paper the focus is being put on studying energy management strengths and weaknesses which can lead to a qualitative understanding of the performance of the organizational structure, this work also focuses on the management settings concerning energy efficiency. If the organization wants to win by integrating energy policy, high-quality communication or promotion of energy efficiency issues should be employed. Marine plastic debris challenges fishing carriers on the African Union route. A possible beneficial solution for shipowners is discussed in this study.","PeriodicalId":49681,"journal":{"name":"Polish Maritime Research","volume":"29 1","pages":"69 - 77"},"PeriodicalIF":2.0,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48998230","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}
Abstract The article presents an innovative method of corrosion tests using the acoustic emission method and the corrosion tester. The problem of corrosion occurring in ballast tanks and tanks carrying petroleum products is discussed. The acoustic method is presented which, due to the use of a unique corrosion tester, is used to monitor the course of corrosion processes in steel. The principle of operation of the corrosion tester, its construction and its use in Non Destructive Testing (NDT) are described in detail. Corrosion test results, obtained with the use of a corrosion tester, are presented. An analysis and a short discussion of the obtained results are given. The results of both the acoustic and metallographic tests prove the possibility of detecting material damage occurring during the operation of the corrosion tester, allowing determination of the course and type of corrosion damage.
{"title":"Application of the Corrosion Tester in Corrosion Tests Using the Acoustic Emission Method","authors":"Krzysztof Emilianowicz, M. Supernak, A. Ossowska","doi":"10.2478/pomr-2022-0037","DOIUrl":"https://doi.org/10.2478/pomr-2022-0037","url":null,"abstract":"Abstract The article presents an innovative method of corrosion tests using the acoustic emission method and the corrosion tester. The problem of corrosion occurring in ballast tanks and tanks carrying petroleum products is discussed. The acoustic method is presented which, due to the use of a unique corrosion tester, is used to monitor the course of corrosion processes in steel. The principle of operation of the corrosion tester, its construction and its use in Non Destructive Testing (NDT) are described in detail. Corrosion test results, obtained with the use of a corrosion tester, are presented. An analysis and a short discussion of the obtained results are given. The results of both the acoustic and metallographic tests prove the possibility of detecting material damage occurring during the operation of the corrosion tester, allowing determination of the course and type of corrosion damage.","PeriodicalId":49681,"journal":{"name":"Polish Maritime Research","volume":"29 1","pages":"167 - 175"},"PeriodicalIF":2.0,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45740698","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}
Abstract Under the recent background of ‘Green Shipping’ and rising fuel prices, it is very important to reduce the fuel consumption rate of ships, which is directly affected by the performance of the main engine. A reasonable maintenance schedule can optimise the performance of the main engine. However, a traditional maintenance schedule is based on the navigation distance and time, ignoring many other factors, such as a harsh working environments and frequently changing operating conditions, which will lead to faster performance degradation. In this study, a real-time evaluation method combing big data of ship energy efficiency with physics-based analysis is proposed to judge the degradation of main engine performance and assist in determining the maintenance schedule. Firstly, based on the developed ship energy efficiency big data platform, the distribution statistics and comparison of different operating states are carried out. Gaussian mixture model (GMM) and Density-Based Spatial Clustering of Applications with Noise (DBSCAN) are used to cluster the data and the high-density data areas are obtained as the analysis points. Then, the data of the analysis points are polynomial fitted, by the least square method, to obtain the propulsion characteristics curves, load characteristic curves, and speed characteristic curves, which can be used to observe the performance degradation of the main engine. The results show that this method can effectively monitor the degradation degree of the main engine performance, and is of great significance to fuel efficiency improvements and greenhouse gas (GHG) emissions reduction.
{"title":"Monitoring the Performance of a Ship’s Main Engine Based on Big Data Technology","authors":"Meng Liang, Mingzhi Chen","doi":"10.2478/pomr-2022-0033","DOIUrl":"https://doi.org/10.2478/pomr-2022-0033","url":null,"abstract":"Abstract Under the recent background of ‘Green Shipping’ and rising fuel prices, it is very important to reduce the fuel consumption rate of ships, which is directly affected by the performance of the main engine. A reasonable maintenance schedule can optimise the performance of the main engine. However, a traditional maintenance schedule is based on the navigation distance and time, ignoring many other factors, such as a harsh working environments and frequently changing operating conditions, which will lead to faster performance degradation. In this study, a real-time evaluation method combing big data of ship energy efficiency with physics-based analysis is proposed to judge the degradation of main engine performance and assist in determining the maintenance schedule. Firstly, based on the developed ship energy efficiency big data platform, the distribution statistics and comparison of different operating states are carried out. Gaussian mixture model (GMM) and Density-Based Spatial Clustering of Applications with Noise (DBSCAN) are used to cluster the data and the high-density data areas are obtained as the analysis points. Then, the data of the analysis points are polynomial fitted, by the least square method, to obtain the propulsion characteristics curves, load characteristic curves, and speed characteristic curves, which can be used to observe the performance degradation of the main engine. The results show that this method can effectively monitor the degradation degree of the main engine performance, and is of great significance to fuel efficiency improvements and greenhouse gas (GHG) emissions reduction.","PeriodicalId":49681,"journal":{"name":"Polish Maritime Research","volume":"29 1","pages":"128 - 140"},"PeriodicalIF":2.0,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43369703","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}
Abstract The paper presents a proposal for a formalised approach to hull shape optimisation with respect to total resistance, by fine-tuning longitudinal volume distribution. An algorithm for automated modification of the hull is presented, allowing for varying the sectional area distribution with a negligible influence on the resulting displacement. Computational fluid dynamics (CFD) solver STAR-CCM+ and computer computer-aided design (CAD) software NX were used to search the optimal volume distribution of selected parent shapes, with respect to total resistance. The bow part and the aft part were optimised separately. The resulting resistances of the selected optimal shapes were then verified by means of scale model tests, realised in the towing tank at the Maritime Advanced Research Centre (CTO) S.A. A noticeable gain in total resistance was achieved and confirmed by experimental tests. The proposed approach seems to be a promising method for relatively quick parametric optimisation of the designed hull shapes; it is also applicable for generic CFD optimisation studies.
{"title":"CFD Optimisation of the Longitudinal Volume Distribution of a Ship’s Hull by Constrained Transformation of the Sectional Area Curve","authors":"M. Kraskowski","doi":"10.2478/pomr-2022-0022","DOIUrl":"https://doi.org/10.2478/pomr-2022-0022","url":null,"abstract":"Abstract The paper presents a proposal for a formalised approach to hull shape optimisation with respect to total resistance, by fine-tuning longitudinal volume distribution. An algorithm for automated modification of the hull is presented, allowing for varying the sectional area distribution with a negligible influence on the resulting displacement. Computational fluid dynamics (CFD) solver STAR-CCM+ and computer computer-aided design (CAD) software NX were used to search the optimal volume distribution of selected parent shapes, with respect to total resistance. The bow part and the aft part were optimised separately. The resulting resistances of the selected optimal shapes were then verified by means of scale model tests, realised in the towing tank at the Maritime Advanced Research Centre (CTO) S.A. A noticeable gain in total resistance was achieved and confirmed by experimental tests. The proposed approach seems to be a promising method for relatively quick parametric optimisation of the designed hull shapes; it is also applicable for generic CFD optimisation studies.","PeriodicalId":49681,"journal":{"name":"Polish Maritime Research","volume":"29 1","pages":"11 - 20"},"PeriodicalIF":2.0,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49013735","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}
M. Zieja, W. Wawrzyński, J. Tomaszewska, Norbert Sigiel
Abstract Image acquisition from autonomous underwater vehicles (AUVs) is useful for mapping objects on the seabed. However, there are few studies on the interpretation of data collected with side-scan sonar during autonomous underwater vehicle missions. By recording the seabed with 3D multibeam sonar, a large number of survey points can be obtained. The collected data are processed using applications based on remote sensing image processing. The data collected during AUV missions (or other sonar carriers) needs to be pre-processed to reach the proper effectiveness level. This process includes corrections of signal amplification (Time Varying Gain, or TVG) and geometric distortions of sonar images (Slant Range Corrections). It should be mentioned that, when carrying out the interpretation process for structures on the sea floor, sonar users need to understand the process of visualising seabed projections and depressions, as well as the resolution limitations of the sonar sensors.
{"title":"A Method for the Interpretation of Sonar Data Recorded during Autonomous Underwater Vehicle Missions","authors":"M. Zieja, W. Wawrzyński, J. Tomaszewska, Norbert Sigiel","doi":"10.2478/pomr-2022-0038","DOIUrl":"https://doi.org/10.2478/pomr-2022-0038","url":null,"abstract":"Abstract Image acquisition from autonomous underwater vehicles (AUVs) is useful for mapping objects on the seabed. However, there are few studies on the interpretation of data collected with side-scan sonar during autonomous underwater vehicle missions. By recording the seabed with 3D multibeam sonar, a large number of survey points can be obtained. The collected data are processed using applications based on remote sensing image processing. The data collected during AUV missions (or other sonar carriers) needs to be pre-processed to reach the proper effectiveness level. This process includes corrections of signal amplification (Time Varying Gain, or TVG) and geometric distortions of sonar images (Slant Range Corrections). It should be mentioned that, when carrying out the interpretation process for structures on the sea floor, sonar users need to understand the process of visualising seabed projections and depressions, as well as the resolution limitations of the sonar sensors.","PeriodicalId":49681,"journal":{"name":"Polish Maritime Research","volume":"29 1","pages":"176 - 186"},"PeriodicalIF":2.0,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49239449","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}
Hong Shi, Qianwei Zhang, M. Liu, Kaijie Yang, Jie Yuan
Abstract A marine gas turbine enclosure must be designed to prevent overheating of the electrical and engine control components as well as diluting potential fuel leaks. In order to achieve an optimal enclosure design, a numerical study of the ventilation-ejection cooling mechanism of a gas turbine enclosure is carried out in this paper. The evaluation index of the ejection cooling performance is first proposed and the algorithm of numerical simulation is verified. On this basis, orthogonal combinations of structural parameters are carried out for the expansion angle α of the lobed nozzle and the spacing S between the outlet plane of the lobed nozzle and the inlet plane of the mixing tube. The flow and the temperature distribution inside the enclosure are analysed under different operating conditions. The results show that the influence of the lobed nozzle expansion angle α and the spacing S on the performance is not a single-valued function but the two influencing factors are mutually constrained and influenced by each other. For any spacing, the combined coefficient is optimal for the expansion angle α = 30°. When the expansion angle α = 45° and the spacing S = 100 mm, the combined coefficient and the temperature distribution inside the enclosure are optimal at the same time.
{"title":"Numerical Study of the Ejection Cooling Mechanism of Ventilation for a Marine Gas Turbine Enclosure","authors":"Hong Shi, Qianwei Zhang, M. Liu, Kaijie Yang, Jie Yuan","doi":"10.2478/pomr-2022-0032","DOIUrl":"https://doi.org/10.2478/pomr-2022-0032","url":null,"abstract":"Abstract A marine gas turbine enclosure must be designed to prevent overheating of the electrical and engine control components as well as diluting potential fuel leaks. In order to achieve an optimal enclosure design, a numerical study of the ventilation-ejection cooling mechanism of a gas turbine enclosure is carried out in this paper. The evaluation index of the ejection cooling performance is first proposed and the algorithm of numerical simulation is verified. On this basis, orthogonal combinations of structural parameters are carried out for the expansion angle α of the lobed nozzle and the spacing S between the outlet plane of the lobed nozzle and the inlet plane of the mixing tube. The flow and the temperature distribution inside the enclosure are analysed under different operating conditions. The results show that the influence of the lobed nozzle expansion angle α and the spacing S on the performance is not a single-valued function but the two influencing factors are mutually constrained and influenced by each other. For any spacing, the combined coefficient is optimal for the expansion angle α = 30°. When the expansion angle α = 45° and the spacing S = 100 mm, the combined coefficient and the temperature distribution inside the enclosure are optimal at the same time.","PeriodicalId":49681,"journal":{"name":"Polish Maritime Research","volume":"29 1","pages":"119 - 127"},"PeriodicalIF":2.0,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44041785","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}
Viktor Yalama, O. Yakovleva, Volodymyr Trandafilov, M. Khmelniuk
Abstract For the maritime sector to be sustainable and to have an intact blue economy, shipowners should be ready to implement Ship Energy Efficiency Management Plans alongside energy efficiency projects. The problem for organizations and shipowners having fishing carriers older than 20 years is highlighted and the following challenges arise for decision-making authorities. To keep such ships in the fleet for the next decade, shipowners should deploy energy efficiency projects for marine system retrofitting to improve energy efficiency and meet environmental regulations. An energy audit is performed and an energy efficiency program is proposed with guidelines for regulations that are currently coming into force. To improve energy efficiency, reduce the environmental impact, and cut fuel consumption costs, marine system retrofitting is done, in a particular case, with two options proposed. The first is a cascade refrigeration system with hydrocarbons and carbon dioxide, where the shipowner gains an energy efficiency improvement of about 20%. The second option is a two-stage refrigeration system with ammonium as the environmentally friendly refrigerant, which improves the energy efficiency by about 26%. Technical and economic issues have been discussed.
{"title":"Future Sustainable Maritime Sector: Energy Efficiency Improvement and Environmental Impact Reduction for Fishing Carriers Older than 20 Years in the Fleet Part II","authors":"Viktor Yalama, O. Yakovleva, Volodymyr Trandafilov, M. Khmelniuk","doi":"10.2478/pomr-2022-0028","DOIUrl":"https://doi.org/10.2478/pomr-2022-0028","url":null,"abstract":"Abstract For the maritime sector to be sustainable and to have an intact blue economy, shipowners should be ready to implement Ship Energy Efficiency Management Plans alongside energy efficiency projects. The problem for organizations and shipowners having fishing carriers older than 20 years is highlighted and the following challenges arise for decision-making authorities. To keep such ships in the fleet for the next decade, shipowners should deploy energy efficiency projects for marine system retrofitting to improve energy efficiency and meet environmental regulations. An energy audit is performed and an energy efficiency program is proposed with guidelines for regulations that are currently coming into force. To improve energy efficiency, reduce the environmental impact, and cut fuel consumption costs, marine system retrofitting is done, in a particular case, with two options proposed. The first is a cascade refrigeration system with hydrocarbons and carbon dioxide, where the shipowner gains an energy efficiency improvement of about 20%. The second option is a two-stage refrigeration system with ammonium as the environmentally friendly refrigerant, which improves the energy efficiency by about 26%. Technical and economic issues have been discussed.","PeriodicalId":49681,"journal":{"name":"Polish Maritime Research","volume":"29 1","pages":"78 - 88"},"PeriodicalIF":2.0,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49388239","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}
Abstract In the modern world, environmental issues come to the fore. The document of MARPOL for reducing the emission of pollutants into the atmosphere relates to the energy efficiency coefficient EEDI. This coefficient is directly related to the power of the main engine and, accordingly, to the water resistance. The way to reduce the energy efficiency factor EEDI by increasing the relative length LV3 {L over {root 3 of V }} of the ship was proposed in this article. To determine the maximum value of the relative length, knowledge of the general strength of the vessel is required. The value of the relative section modulus of an equivalent girder for a small vessel of transitional mode is defined. The result of the graphic solution of two equations is the value of such a relative section modulus. This parameter is required to determine the limiting value of the relative length and to find solutions to reduce the coefficient EEDI. Comparative analysis of the obtained data with the data of the strength and weight of the H-girder with a length similar to the ship was conducted. The formula for determining the limiting value of the relative length was obtained from the equation of general strength. For a preliminary assessment of the future project of the ship, in terms of permissible design accelerations and the possibility of the ship moving against a sea wave of a certain height, a graph was built based on the application of the energy wave criterion EWC and the requirements of various classification societies.
在现代社会，环境问题是一个突出的问题。MARPOL关于减少污染物排放到大气中的文件涉及能源效率系数EEDI。这个系数与主机的功率直接相关，因此也与水阻力有关。本文提出了通过增加船舶的相对长度LV3 {L / {root 3 of V}}来降低能效系数EEDI的方法。为了确定相对长度的最大值，需要了解容器的一般强度。定义了过渡模态小型船舶等效梁的相对截面模量。两个方程的图形解的结果就是这种相对截面模量的值。需要这个参数来确定相对长度的极限值，并找到降低EEDI系数的解。将所得数据与长度与船体相近的h型梁的强度和重量数据进行了对比分析。由一般强度方程得到了确定相对长度极限值的公式。为了对船舶的未来项目进行初步评估，根据允许的设计加速度和船舶在一定高度的海浪中移动的可能性，根据能量波准则EWC的应用和各个船级社的要求，建立了一个图表。
{"title":"General Strength, Energy Efficiency (EEDI), and Energy Wave Criterion (EWC) of Deadrise Hulls for Transitional Mode","authors":"O. Kanifolskyi","doi":"10.2478/pomr-2022-0021","DOIUrl":"https://doi.org/10.2478/pomr-2022-0021","url":null,"abstract":"Abstract In the modern world, environmental issues come to the fore. The document of MARPOL for reducing the emission of pollutants into the atmosphere relates to the energy efficiency coefficient EEDI. This coefficient is directly related to the power of the main engine and, accordingly, to the water resistance. The way to reduce the energy efficiency factor EEDI by increasing the relative length LV3 {L over {root 3 of V }} of the ship was proposed in this article. To determine the maximum value of the relative length, knowledge of the general strength of the vessel is required. The value of the relative section modulus of an equivalent girder for a small vessel of transitional mode is defined. The result of the graphic solution of two equations is the value of such a relative section modulus. This parameter is required to determine the limiting value of the relative length and to find solutions to reduce the coefficient EEDI. Comparative analysis of the obtained data with the data of the strength and weight of the H-girder with a length similar to the ship was conducted. The formula for determining the limiting value of the relative length was obtained from the equation of general strength. For a preliminary assessment of the future project of the ship, in terms of permissible design accelerations and the possibility of the ship moving against a sea wave of a certain height, a graph was built based on the application of the energy wave criterion EWC and the requirements of various classification societies.","PeriodicalId":49681,"journal":{"name":"Polish Maritime Research","volume":"29 1","pages":"4 - 10"},"PeriodicalIF":2.0,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45855994","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}
Abstract This paper proposes a navigation situation assessment method for autonomous surface vehicles (ASVs) in a cooperative hunting environment. By virtue of the repulsion function expressed in the artificial potential field, the navigation situation of hunting ASVs and target ASVs is firstly described. And the hunting situation is also constructed to describe the cooperative hunting. Based on the navigation situation and the hunting situation, a navigation situation assessment method for cooperative hunting of multiple ASVs is designed, where the number of hunting vehicles and the hunting radius can be successfully computed. Simulation results show that this proposed situation assessment method can give an optimised formation pattern and provide an effective reference for cooperative hunting of ASVs.
{"title":"Navigation Situation Assessment of Autonomous Surface Vehicles in a Cooperative Hunting Environment","authors":"Wenjun Zhang, Fuqiang Wang, Qiqiang Gao, Xingru Qu","doi":"10.2478/pomr-2022-0013","DOIUrl":"https://doi.org/10.2478/pomr-2022-0013","url":null,"abstract":"Abstract This paper proposes a navigation situation assessment method for autonomous surface vehicles (ASVs) in a cooperative hunting environment. By virtue of the repulsion function expressed in the artificial potential field, the navigation situation of hunting ASVs and target ASVs is firstly described. And the hunting situation is also constructed to describe the cooperative hunting. Based on the navigation situation and the hunting situation, a navigation situation assessment method for cooperative hunting of multiple ASVs is designed, where the number of hunting vehicles and the hunting radius can be successfully computed. Simulation results show that this proposed situation assessment method can give an optimised formation pattern and provide an effective reference for cooperative hunting of ASVs.","PeriodicalId":49681,"journal":{"name":"Polish Maritime Research","volume":"29 1","pages":"19 - 26"},"PeriodicalIF":2.0,"publicationDate":"2022-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46090650","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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