Abstract This report examines the feasibility and impact of retrofitting the bulbous bow on a general cargo ship, in terms of the energy efficiency operational index (EEOI), in the areas of Western Europe and the Eastern Mediterranean. Three ship forms were developed and analysed: with a bulbous bow, without a bulbous bow, and with a modified bulbous bow. The goal in developing the ship forms and conducting the analysis was to achieve minimal differences in the ship’s characteristics with the same volumetric displacement, aided by PolyCAD software. A route was selected between two ports: Varna and Rotterdam. The labour intensity of the bulbous bow retrofitting process was evaluated and approximate values of labours costs and cost for the task were determined. The results obtained for resistance during ship motion, EEOI, and fuel consumption reductions, or increases, were compared against the retrofitting values. The return cost of retrofitting is evaluated and measured in terms of fuel saved.
{"title":"Retrofitting the Bow of a General Cargo Vessel Andevaluating Energy Efficiency Operational Index","authors":"Yordan Denev","doi":"10.2478/pomr-2023-0054","DOIUrl":"https://doi.org/10.2478/pomr-2023-0054","url":null,"abstract":"Abstract This report examines the feasibility and impact of retrofitting the bulbous bow on a general cargo ship, in terms of the energy efficiency operational index (EEOI), in the areas of Western Europe and the Eastern Mediterranean. Three ship forms were developed and analysed: with a bulbous bow, without a bulbous bow, and with a modified bulbous bow. The goal in developing the ship forms and conducting the analysis was to achieve minimal differences in the ship’s characteristics with the same volumetric displacement, aided by PolyCAD software. A route was selected between two ports: Varna and Rotterdam. The labour intensity of the bulbous bow retrofitting process was evaluated and approximate values of labours costs and cost for the task were determined. The results obtained for resistance during ship motion, EEOI, and fuel consumption reductions, or increases, were compared against the retrofitting values. The return cost of retrofitting is evaluated and measured in terms of fuel saved.","PeriodicalId":49681,"journal":{"name":"Polish Maritime Research","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139016763","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}
Jan Sierzputowski, A. Karczewski, Przemysław Krata
Abstract A sailing yacht is a human-centred product, the design of which revolves primarily around the wants and desires of the future owner. In most cases, these preferences are not measurable, such as a personal aesthetic feeling, or a need for comfort, speed, safety etc. The aims of this paper are to demonstrate that these preferences can be classified and represented numerically, and to show that they are correlated with the type of yacht owned. As a case study, the owner’s preferences for deck equipment are considered. These are determined by pairwise comparisons of the importance rankings for features previously defined by yacht owners, following the analytic hierarchy process (AHP) method. As a result, a quantitative representation of these preferences is established, and they are shown to be correlated with the type of yacht. The findings of the current study show that the yacht owners’ preferences can be represented numerically, leading to a utilitarian conclusion that concerns the support and even some degree of automation of the design process.
{"title":"Use of the AHP Method for Preference Determination in Yacht Design","authors":"Jan Sierzputowski, A. Karczewski, Przemysław Krata","doi":"10.2478/pomr-2023-0055","DOIUrl":"https://doi.org/10.2478/pomr-2023-0055","url":null,"abstract":"Abstract A sailing yacht is a human-centred product, the design of which revolves primarily around the wants and desires of the future owner. In most cases, these preferences are not measurable, such as a personal aesthetic feeling, or a need for comfort, speed, safety etc. The aims of this paper are to demonstrate that these preferences can be classified and represented numerically, and to show that they are correlated with the type of yacht owned. As a case study, the owner’s preferences for deck equipment are considered. These are determined by pairwise comparisons of the importance rankings for features previously defined by yacht owners, following the analytic hierarchy process (AHP) method. As a result, a quantitative representation of these preferences is established, and they are shown to be correlated with the type of yacht. The findings of the current study show that the yacht owners’ preferences can be represented numerically, leading to a utilitarian conclusion that concerns the support and even some degree of automation of the design process.","PeriodicalId":49681,"journal":{"name":"Polish Maritime Research","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139021303","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 utilisation of the thermal emissions of modern ship power plants requires the development and implementation of essentially new methods of using low-temperature waste heat. Thermoacoustic technologies are able to effectively use low-temperature and cryogenic heat resources with a potential difference of 500–111 K. Thermoacoustic heat machines (TAHMs) are characterised by high reliability, simplicity and environmental safety. The wide implementation of thermoacoustic energy-saving systems is hampered by the low specific power and the difficulties of directly producing mechanical work. An efficient approach to converting acoustic energy into mechanical work entails the utilisation of axial pulse bidirectional turbines within thermoacoustic heat engines. These thermoacoustic turbogenerators represent comprehensive systems that consist of thermoacoustic primary movers with an electric generator actuated by an axial-pulse bidirectional turbine. The development of such a thermoacoustic turbogenerator requires several fundamental issues to be solved. For this purpose, a suitable experimental setup and a 3D computational fluid dynamics (CFD) model of a thermoacoustic engine (TAE) with bidirectional turbines were created. The research program involved conducting physical experiments and the CFD modelling of processes in a TAE resonator with an installed bidirectional turbine. The boundary and initial conditions for CFD calculations were based on empirical data. The adequacy of the developed numerical model was substantiated by the results of physical experiments. The CFD results showed that the most significant energy losses in bidirectional turbines are manifested in the output grid of the turbine.
摘要 现代船舶发电厂热排放的利用需要开发和实施新的低温废热利用方法。热声技术能够有效利用电位差为 500-111 K 的低温和低温热资源。热声热机（TAHM）的特点是可靠性高、操作简单和环保安全。热声节能系统的广泛应用受到比功率低和难以直接产生机械功的阻碍。将声能转化为机械功的有效方法是在热声热机中利用轴向脉冲双向涡轮。这些热声涡轮发电机是由热声原动机和由轴向脉冲双向涡轮驱动的发电机组成的综合系统。开发这种热声涡轮发电机需要解决几个基本问题。为此，我们创建了一个合适的实验装置和带有双向涡轮的热声发动机（TAE）的三维计算流体动力学（CFD）模型。研究计划包括在安装了双向涡轮机的热声发动机（TAE）谐振器中进行物理实验和 CFD 过程建模。CFD 计算的边界和初始条件以经验数据为基础。物理实验结果证明了所开发数值模型的适当性。CFD 结果表明，双向涡轮机最显著的能量损失体现在涡轮机的输出电网上。
{"title":"Exploration of a Model Thermoacoustic Turbogenerator with a Bidirectional Turbine","authors":"V. Korobko, S. Serbin, Huu Cuong Le","doi":"10.2478/pomr-2023-0063","DOIUrl":"https://doi.org/10.2478/pomr-2023-0063","url":null,"abstract":"Abstract The utilisation of the thermal emissions of modern ship power plants requires the development and implementation of essentially new methods of using low-temperature waste heat. Thermoacoustic technologies are able to effectively use low-temperature and cryogenic heat resources with a potential difference of 500–111 K. Thermoacoustic heat machines (TAHMs) are characterised by high reliability, simplicity and environmental safety. The wide implementation of thermoacoustic energy-saving systems is hampered by the low specific power and the difficulties of directly producing mechanical work. An efficient approach to converting acoustic energy into mechanical work entails the utilisation of axial pulse bidirectional turbines within thermoacoustic heat engines. These thermoacoustic turbogenerators represent comprehensive systems that consist of thermoacoustic primary movers with an electric generator actuated by an axial-pulse bidirectional turbine. The development of such a thermoacoustic turbogenerator requires several fundamental issues to be solved. For this purpose, a suitable experimental setup and a 3D computational fluid dynamics (CFD) model of a thermoacoustic engine (TAE) with bidirectional turbines were created. The research program involved conducting physical experiments and the CFD modelling of processes in a TAE resonator with an installed bidirectional turbine. The boundary and initial conditions for CFD calculations were based on empirical data. The adequacy of the developed numerical model was substantiated by the results of physical experiments. The CFD results showed that the most significant energy losses in bidirectional turbines are manifested in the output grid of the turbine.","PeriodicalId":49681,"journal":{"name":"Polish Maritime Research","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138989063","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 functional layout of fire safety equipment in technical spaces of ships is a time-consuming process. When designing a ship fire protection system, the designer must manually position each system component in such a way as to meet the requirements of regulations arising from the technical specification, various legal regulations of maritime conventions and classification societies of the vessel to be designed. Layout of fire hydrants assisted by a computer that is based on pre-defined criteria and various constraints could significantly support the designer in working easier and faster. This paper presents a prototype computer-aided design system that enables optimal placement of fire hydrants using the metaheuristic Particle Swarm Optimization (PSO) algorithm. This algorithm was used in Rhinoceros 3D software with its Grasshopper plugin for visualizing the arrangement of fire safety equipment. Various solution arrangements compared with the fire hydrant placement in real ships are illustrated by a case study. Demonstrating how design work can be facilitated and what potential benefits can be achieved are presented as well.
摘要 船舶技术空间消防安全设备的功能布局是一个耗时的过程。在设计船舶消防系统时，设计人员必须手动定位每个系统组件，以满足所设计船舶的技术规范、海事公约和船级社的各种法律规定的要求。根据预先确定的标准和各种约束条件，通过计算机辅助进行消火栓布局，可以大大提高设计人员的工作效率。本文介绍了一种计算机辅助设计系统原型，该系统利用元启发式粒子群优化（PSO）算法实现了消火栓的最佳布置。该算法被用于 Rhinoceros 3D 软件及其 Grasshopper 插件，以实现消防安全设备布置的可视化。通过一个案例研究，说明了与实际船舶中消火栓布置相比较的各种解决方案安排。此外，还展示了如何促进设计工作以及可实现的潜在效益。
{"title":"Computer-Aided System for Layout of Fire Hydrants on Boards Designed Vessel Using the Particle Swarm Optimization Algorithm","authors":"Piotr Gomułka","doi":"10.2478/pomr-2023-0053","DOIUrl":"https://doi.org/10.2478/pomr-2023-0053","url":null,"abstract":"Abstract The functional layout of fire safety equipment in technical spaces of ships is a time-consuming process. When designing a ship fire protection system, the designer must manually position each system component in such a way as to meet the requirements of regulations arising from the technical specification, various legal regulations of maritime conventions and classification societies of the vessel to be designed. Layout of fire hydrants assisted by a computer that is based on pre-defined criteria and various constraints could significantly support the designer in working easier and faster. This paper presents a prototype computer-aided design system that enables optimal placement of fire hydrants using the metaheuristic Particle Swarm Optimization (PSO) algorithm. This algorithm was used in Rhinoceros 3D software with its Grasshopper plugin for visualizing the arrangement of fire safety equipment. Various solution arrangements compared with the fire hydrant placement in real ships are illustrated by a case study. Demonstrating how design work can be facilitated and what potential benefits can be achieved are presented as well.","PeriodicalId":49681,"journal":{"name":"Polish Maritime Research","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138992686","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 recent years, issues related to the impact of human activity on the natural environment have become pressing, and the challenge of global warming necessitates immediate action. To support environmental protection efforts, it has become imperative to adopt a broader perspective when evaluating various products and systems. A valuable tool for such assessments is a life cycle assessment (LCA), which enables a comprehensive analysis of the entire life cycle of a product. This paper presents a comparative analysis of the hull of a fast patrol craft, fabricated using three different materials: steel, aluminium, and composite materials. The LCA covers every stage from material production, through the construction and use of the hull, to its eventual disposal. A specific criterion was established to evaluate the impact of the hull on the environment, with clearly defined system boundaries. In the final section, we draw some conclusions that underscore the importance of reusing construction materials. By emphasising this approach, ecological footprints can be minimised and a sustainable future can be created.
{"title":"Analysis of the Environmental Impact of the Hull Construction of a Small Vessel Based on LCA","authors":"Jacek Nakielski","doi":"10.2478/pomr-2023-0058","DOIUrl":"https://doi.org/10.2478/pomr-2023-0058","url":null,"abstract":"Abstract In recent years, issues related to the impact of human activity on the natural environment have become pressing, and the challenge of global warming necessitates immediate action. To support environmental protection efforts, it has become imperative to adopt a broader perspective when evaluating various products and systems. A valuable tool for such assessments is a life cycle assessment (LCA), which enables a comprehensive analysis of the entire life cycle of a product. This paper presents a comparative analysis of the hull of a fast patrol craft, fabricated using three different materials: steel, aluminium, and composite materials. The LCA covers every stage from material production, through the construction and use of the hull, to its eventual disposal. A specific criterion was established to evaluate the impact of the hull on the environment, with clearly defined system boundaries. In the final section, we draw some conclusions that underscore the importance of reusing construction materials. By emphasising this approach, ecological footprints can be minimised and a sustainable future can be created.","PeriodicalId":49681,"journal":{"name":"Polish Maritime Research","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139020139","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}
Volodimir Leshchev, Igor Maslov, Oleksandr Palagin, Andrii Naydyonov
Abstract The relevance of this study lies in the fact that it presents a mathematical model of the dynamics of the propulsion system of a ship that takes into consideration the mass of water added to it. The influence of this phenomenon on the resonant frequencies of the propeller shaft is examined, and a transfer function for a controllable-pitch propeller is obtained for various operating modes. The purpose of the study is to improve the calculation of the dynamic operating modes of a controllable-pitch propeller by examining the features of a visual models. The VisSim software package is used in the study. A visual model is developed that considers the influence of the rotational speed on the value of the rotational inertia attached to the variable-pitch screw of the mass of water, and a special transfer function is proposed. The study shows that a transfer function of this type has a loop enabling negative feedback. An analysis of the operation of the propeller shaft at its resonant frequency is conducted based on the application of frequency characteristics using the transfer functions obtained. We show that in the low-frequency region, a consideration of the added rotational inertia using the proposed transfer function leads to a significant difference compared to the result obtained with the existing calculation method.
{"title":"Transfer Function for a Controllable Pitch Propeller with Added Water Mass","authors":"Volodimir Leshchev, Igor Maslov, Oleksandr Palagin, Andrii Naydyonov","doi":"10.2478/pomr-2023-0060","DOIUrl":"https://doi.org/10.2478/pomr-2023-0060","url":null,"abstract":"Abstract The relevance of this study lies in the fact that it presents a mathematical model of the dynamics of the propulsion system of a ship that takes into consideration the mass of water added to it. The influence of this phenomenon on the resonant frequencies of the propeller shaft is examined, and a transfer function for a controllable-pitch propeller is obtained for various operating modes. The purpose of the study is to improve the calculation of the dynamic operating modes of a controllable-pitch propeller by examining the features of a visual models. The VisSim software package is used in the study. A visual model is developed that considers the influence of the rotational speed on the value of the rotational inertia attached to the variable-pitch screw of the mass of water, and a special transfer function is proposed. The study shows that a transfer function of this type has a loop enabling negative feedback. An analysis of the operation of the propeller shaft at its resonant frequency is conducted based on the application of frequency characteristics using the transfer functions obtained. We show that in the low-frequency region, a consideration of the added rotational inertia using the proposed transfer function leads to a significant difference compared to the result obtained with the existing calculation method.","PeriodicalId":49681,"journal":{"name":"Polish Maritime Research","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139017480","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}
D. Minchev, R.A. Varbanets, Oleksandr Shumylo, V.I. Zalozh, N. Aleksandrovska, Pavlo Bratchenko, Thanh Hai Truong
Abstract The application of Digital Twins is a promising solution for enhancing the efficiency of marine power plant operation, particularly their important components – marine internal combustion engines (ICE). This work presents the concept of applying a Performance Digital Twin for monitoring the technical condition and diagnosing malfunctions of marine ICE, along with its implementation on an experimental test-bench, based on a marine diesel-generator. The main principles of implementing this concept involve data transmission technologies, from the sensors installed on the engine to a server. The Digital Twin, also operating on the server, is used to automatically process the acquired experimental data, accumulate statistics, determine the current technical state of the engine, identify possible malfunctions, and make decisions regarding changes in operating programs. The core element of the Digital Twin is a mathematical model of the marine diesel engine’s operating cycle. In its development, significant attention was devoted to refining the fuel combustion model, as the combustion processes significantly impact both the engine’s fuel efficiency and the level of toxic emissions of exhaust gases. The enhanced model differs from the base model, by considering the variable value of the average droplets’ diameter during fuel injection. This influence on fuel vapourisation, combustion, and the formation of toxic components is substantial, as shown. Using the example of calibrating the model to the test results of a diesel engine under 27 operating modes, it is demonstrated that the application of the improved combustion model allows better adjustment of the Digital Twin to experimental data, thus achieving a more accurate correspondence to a real engine.
{"title":"Digital Twin Test-Bench Performance for Marine Diesel Engine Applications","authors":"D. Minchev, R.A. Varbanets, Oleksandr Shumylo, V.I. Zalozh, N. Aleksandrovska, Pavlo Bratchenko, Thanh Hai Truong","doi":"10.2478/pomr-2023-0061","DOIUrl":"https://doi.org/10.2478/pomr-2023-0061","url":null,"abstract":"Abstract The application of Digital Twins is a promising solution for enhancing the efficiency of marine power plant operation, particularly their important components – marine internal combustion engines (ICE). This work presents the concept of applying a Performance Digital Twin for monitoring the technical condition and diagnosing malfunctions of marine ICE, along with its implementation on an experimental test-bench, based on a marine diesel-generator. The main principles of implementing this concept involve data transmission technologies, from the sensors installed on the engine to a server. The Digital Twin, also operating on the server, is used to automatically process the acquired experimental data, accumulate statistics, determine the current technical state of the engine, identify possible malfunctions, and make decisions regarding changes in operating programs. The core element of the Digital Twin is a mathematical model of the marine diesel engine’s operating cycle. In its development, significant attention was devoted to refining the fuel combustion model, as the combustion processes significantly impact both the engine’s fuel efficiency and the level of toxic emissions of exhaust gases. The enhanced model differs from the base model, by considering the variable value of the average droplets’ diameter during fuel injection. This influence on fuel vapourisation, combustion, and the formation of toxic components is substantial, as shown. Using the example of calibrating the model to the test results of a diesel engine under 27 operating modes, it is demonstrated that the application of the improved combustion model allows better adjustment of the Digital Twin to experimental data, thus achieving a more accurate correspondence to a real engine.","PeriodicalId":49681,"journal":{"name":"Polish Maritime Research","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139019070","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}
Minh Duc Nguyen, Kong Tae Yeon, K. Rudzki, Hoang Phuong Nguyen, Nguyen Dang Khoa Pham
Abstract Logistics centres are currently performing a key function in the development of countries through their ability to regulate goods, markets, and transport. This is shown by the infrastructure, cost, goods flow, and quality of logistical services provided by these centres. Nevertheless, in developing nations or regions with antiquated logistics infrastructure, conventional logistics centres seem to struggle to manage the volume of commodities passing through them, resulting in persistent congestion and an unsteady flow of goods inside these facilities. This issue poses a challenge to the progress of any nation. The emergence of new technology offers a potential avenue to solve the problems inherent in traditional logistics centres. Most prominently, four technologies (the Internet of Things (IoT), Blockchain, Big Data and Cloud computing) are widely applied in traditional logistics centres. This work has conducted a thorough analysis and evaluation of these new technologies in relation to their respective functions and roles inside a logistics centre. Furthermore, this work proposes difficulties in applying new technologies to logistics centres related to issues such as science, energy, cost, or staff qualifications. Finally, future development directions, related to expanding policies in technological applications, or combining each country’s policies for the logistics industry, are carefully discussed.
{"title":"Strategies for Developing Logistics Centres: Technological Trends and Policy Implications","authors":"Minh Duc Nguyen, Kong Tae Yeon, K. Rudzki, Hoang Phuong Nguyen, Nguyen Dang Khoa Pham","doi":"10.2478/pomr-2023-0066","DOIUrl":"https://doi.org/10.2478/pomr-2023-0066","url":null,"abstract":"Abstract Logistics centres are currently performing a key function in the development of countries through their ability to regulate goods, markets, and transport. This is shown by the infrastructure, cost, goods flow, and quality of logistical services provided by these centres. Nevertheless, in developing nations or regions with antiquated logistics infrastructure, conventional logistics centres seem to struggle to manage the volume of commodities passing through them, resulting in persistent congestion and an unsteady flow of goods inside these facilities. This issue poses a challenge to the progress of any nation. The emergence of new technology offers a potential avenue to solve the problems inherent in traditional logistics centres. Most prominently, four technologies (the Internet of Things (IoT), Blockchain, Big Data and Cloud computing) are widely applied in traditional logistics centres. This work has conducted a thorough analysis and evaluation of these new technologies in relation to their respective functions and roles inside a logistics centre. Furthermore, this work proposes difficulties in applying new technologies to logistics centres related to issues such as science, energy, cost, or staff qualifications. Finally, future development directions, related to expanding policies in technological applications, or combining each country’s policies for the logistics industry, are carefully discussed.","PeriodicalId":49681,"journal":{"name":"Polish Maritime Research","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139023466","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 order to explore the potential application of oxygenated fuels, polyoxymethylene dimethyl ethers (PODE), as an alternative fuel for marine diesel engines, the fuel combustion performance and gas emission characteristics of pure diesel oil, diesel-blended PODE, and pure PODE were tested on a marine diesel engine under different running conditions. The experimental results indicate that oxygen consumption can be reduced by diesel-blended PODE and pure PODE. The in-cylinder pressure and exothermic curve were consistent with the trend of diesel oil. Also, the ignition delay of diesel-blended PODE and pure PODE decreased, and the diffusion rate was accelerated, which helped to improve the combustion performance of diesel engines. Diesel blended PODE and pure PODE reduced the particulate matter (PM) emissions by up to 56.9% and 86.8%, respectively, and CO emissions by up to 51.1% and 56.3%, respectively. NOx emissions were gradually decreased with engine load. CO2 emissions were slightly increased, and the effective fuel consumption was increased up to 48% and 132%, respectively. It was shown that PODE could provide comparable power in a marine diesel engine and improve the fuel combustion and gas emission of the engine as a clean alternative fuel for marine diesel engines.
{"title":"Experimental Study of Fuel Combustion and Emission Characteristics of Marine Diesel Engines Using Advanced Fuels","authors":"Li Changxiong, Yihuai Hu, Zy Yang, Hao Guo","doi":"10.2478/pomr-2023-0038","DOIUrl":"https://doi.org/10.2478/pomr-2023-0038","url":null,"abstract":"Abstract In order to explore the potential application of oxygenated fuels, polyoxymethylene dimethyl ethers (PODE), as an alternative fuel for marine diesel engines, the fuel combustion performance and gas emission characteristics of pure diesel oil, diesel-blended PODE, and pure PODE were tested on a marine diesel engine under different running conditions. The experimental results indicate that oxygen consumption can be reduced by diesel-blended PODE and pure PODE. The in-cylinder pressure and exothermic curve were consistent with the trend of diesel oil. Also, the ignition delay of diesel-blended PODE and pure PODE decreased, and the diffusion rate was accelerated, which helped to improve the combustion performance of diesel engines. Diesel blended PODE and pure PODE reduced the particulate matter (PM) emissions by up to 56.9% and 86.8%, respectively, and CO emissions by up to 51.1% and 56.3%, respectively. NOx emissions were gradually decreased with engine load. CO2 emissions were slightly increased, and the effective fuel consumption was increased up to 48% and 132%, respectively. It was shown that PODE could provide comparable power in a marine diesel engine and improve the fuel combustion and gas emission of the engine as a clean alternative fuel for marine diesel engines.","PeriodicalId":49681,"journal":{"name":"Polish Maritime Research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135687995","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 An adaptive neural network (NN) event-triggered trajectory tracking control scheme based on finite time convergence is proposed to address the problem of trajectory tracking control of underdriven surface ships. In this scheme, both NNs and minimum learning parameters (MLPS) are applied. The internal and external uncertainties are approximated by NNs. To reduce the computational complexity, MLPs are used in the proposed controller. An event-triggered technique is then incorporated into the control design to synthesise an adaptive NN-based event-triggered controller with finite-time convergence. Lyapunov theory is applied to prove that all signals are bounded in the tracking system of underactuated vessels, and to show that Zeno behavior can be avoided. The validity of this control scheme is determined based on simulation results, and comparisons with some alternative schemes are presented.
{"title":"Event-Triggered Adaptive Neural Network Trajectory Tracking Control For Underactuated Ships Under Uncertain Disturbance","authors":"Wenxue Su, Qiang Zhang, Yufeng Liu","doi":"10.2478/pomr-2023-0045","DOIUrl":"https://doi.org/10.2478/pomr-2023-0045","url":null,"abstract":"Abstract An adaptive neural network (NN) event-triggered trajectory tracking control scheme based on finite time convergence is proposed to address the problem of trajectory tracking control of underdriven surface ships. In this scheme, both NNs and minimum learning parameters (MLPS) are applied. The internal and external uncertainties are approximated by NNs. To reduce the computational complexity, MLPs are used in the proposed controller. An event-triggered technique is then incorporated into the control design to synthesise an adaptive NN-based event-triggered controller with finite-time convergence. Lyapunov theory is applied to prove that all signals are bounded in the tracking system of underactuated vessels, and to show that Zeno behavior can be avoided. The validity of this control scheme is determined based on simulation results, and comparisons with some alternative schemes are presented.","PeriodicalId":49681,"journal":{"name":"Polish Maritime Research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135688197","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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