Trimaran hull forms have been popular recently in both commercial and military usage due to reduction in resistance at high speeds, better stability, and greater deck area compared to conventional monohull vessels. Determination of the location of the side hulls is most critical to get higher hydrodynamic performance. Therefore, many studies in the literature are related to defining the location of the side hulls for trimaran vessels. Most of the studies have been carried out experimentally or numerically. In this study, an artificial neural network (ANN) model was used to predict the residual resistance coefficient of a trimaran model. The model uses four parameters which are the transverse and longitudinal positions of the side hulls, the longitudinal centre of buoyancy and the Froude number to predict the residual resistance of the trimaran model. The experimental data of the trimaran model were used to train the neural network model in order to develop a more reliable model. Several neural network models were developed and tested to find the one with minimum error. The study showed that the residual resistance coefficients of the trimaran model were predicted with high accuracy levels compared to the model experimental data. It was also shown that an ANN is a useful alternative method to model tests and numerical simulations. The developed model can be used to reduce the number of model tests or numerical simulations as well as to obtain the optimum location of the side hulls in terms of resistance.
{"title":"PREDICTION OF RESIDUAL RESISTANCE OF A TRIMARAN VESSEL BY USING AN ARTIFICIAL NEURAL NETWORK","authors":"Burak Yıldız","doi":"10.21278/brod73107","DOIUrl":"https://doi.org/10.21278/brod73107","url":null,"abstract":"Trimaran hull forms have been popular recently in both commercial and military usage due to reduction in resistance at high speeds, better stability, and greater deck area compared to conventional monohull vessels. Determination of the location of the side hulls is most critical to get higher hydrodynamic performance. Therefore, many studies in the literature are related to defining the location of the side hulls for trimaran vessels. Most of the studies have been carried out experimentally or numerically. In this study, an artificial neural network (ANN) model was used to predict the residual resistance coefficient of a trimaran model. The model uses four parameters which are the transverse and longitudinal positions of the side hulls, the longitudinal centre of buoyancy and the Froude number to predict the residual resistance of the trimaran model. The experimental data of the trimaran model were used to train the neural network model in order to develop a more reliable model. Several neural network models were developed and tested to find the one with minimum error. The study showed that the residual resistance coefficients of the trimaran model were predicted with high accuracy levels compared to the model experimental data. It was also shown that an ANN is a useful alternative method to model tests and numerical simulations. The developed model can be used to reduce the number of model tests or numerical simulations as well as to obtain the optimum location of the side hulls in terms of resistance.","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48967646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Generally, cell guides are installed in the cargo hold of container ships, which improve the loading and unloading efficiency of containers and fix containers when the ship is sailing. However, in actual production, due to the low accuracy of ship loading in sections, and the deviation of welding shrinkage and expansion in relevant sections, errors occur in the loading process of containers, resulting in hidden safety risks or significant economic losses. Given the above situation, it is particularly important to find a high-efficiency cell guide accuracy inspection method for construction monitoring. 3D scanner to obtain three-dimensional data is presented in this paper, based on this paper proposes a new method, this method will be used based on improved instances of 3 d point cloud segmentation model to cell guide the segmentation, and fitting container ship cell guide structure, and then realize the function of container simulation test box, cell guide after the segmentation precision inspection at the same time, for the practicality review, we compared the accuracy data gained from inspection simulation and the measured data. As a result, it was confirmed that both values were within about ±1.5mm. The validity, and reliability of the method are further verified.
{"title":"CONTAINER SHIP CELL GUIDE ACCURACY CHECK TECHNOLOGY BASED ON IMPROVED 3D POINT CLOUD INSTANCE SEGMENTATION","authors":"Chengjie Zong, Zhibo Wan","doi":"10.21278/brod73102","DOIUrl":"https://doi.org/10.21278/brod73102","url":null,"abstract":"Generally, cell guides are installed in the cargo hold of container ships, which improve the loading and unloading efficiency of containers and fix containers when the ship is sailing. However, in actual production, due to the low accuracy of ship loading in sections, and the deviation of welding shrinkage and expansion in relevant sections, errors occur in the loading process of containers, resulting in hidden safety risks or significant economic losses. Given the above situation, it is particularly important to find a high-efficiency cell guide accuracy inspection method for construction monitoring. 3D scanner to obtain three-dimensional data is presented in this paper, based on this paper proposes a new method, this method will be used based on improved instances of 3 d point cloud segmentation model to cell guide the segmentation, and fitting container ship cell guide structure, and then realize the function of container simulation test box, cell guide after the segmentation precision inspection at the same time, for the practicality review, we compared the accuracy data gained from inspection simulation and the measured data. As a result, it was confirmed that both values were within about ±1.5mm. The validity, and reliability of the method are further verified.","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46903304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The demand analysis method of maritime emergency resources is the key technology to promote a reasonable emergency resource allocation during maritime emergency management. It is widely used to improve the efficiency of maritime emergency rescue and reduce the loss of maritime accidents. However, it requires a scientific and effective method of the demand analysis of maritime emergency resources. This paper aims to analyze the underlying modeling paradigms and to assess the extent to which the demand analysis methods of maritime emergency resources can meet the requirements. Focusing on the demand analysis methods, this paper provides a broad overview of the current literature on maritime emergency resources of the last decades, by considering the models’ purposes, theoretical frameworks, factors, and outputs. The results indicate that the existing methods can be classified into three concepts: the linear regression theory, Back Propagation (BP) Neural Network, and Case-based Reasoning (CBR) technology. Combined with the characteristics of China's maritime emergency management field, the interaction between theoretical framework and applications is not sufficiently understood and thus needs to be further studied. Being familiar with knowledge gaps acts as a catalyst for further research on scientific and efficient demand analysis methods of maritime emergency resources in various navigation conditions.
{"title":"REVIEW AND COMPARISON OF THE DEMAND ANALYSIS METHODS OF MARITIME EMERGENCY RESOURCES","authors":"Quandang Ma, Yang Zhou, Lei Liu","doi":"10.21278/brod73108","DOIUrl":"https://doi.org/10.21278/brod73108","url":null,"abstract":"The demand analysis method of maritime emergency resources is the key technology to promote a reasonable emergency resource allocation during maritime emergency management. It is widely used to improve the efficiency of maritime emergency rescue and reduce the loss of maritime accidents. However, it requires a scientific and effective method of the demand analysis of maritime emergency resources. This paper aims to analyze the underlying modeling paradigms and to assess the extent to which the demand analysis methods of maritime emergency resources can meet the requirements. Focusing on the demand analysis methods, this paper provides a broad overview of the current literature on maritime emergency resources of the last decades, by considering the models’ purposes, theoretical frameworks, factors, and outputs. The results indicate that the existing methods can be classified into three concepts: the linear regression theory, Back Propagation (BP) Neural Network, and Case-based Reasoning (CBR) technology. Combined with the characteristics of China's maritime emergency management field, the interaction between theoretical framework and applications is not sufficiently understood and thus needs to be further studied. Being familiar with knowledge gaps acts as a catalyst for further research on scientific and efficient demand analysis methods of maritime emergency resources in various navigation conditions.","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45956560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper presents the development of autonomy capability for an unmanned surface vehicle (USV). The development mainly focuses on the high-level autonomy on perception, path planning, guidance and control to achieve real sea applications of the USV. First, visual recognition and point cloud data processing techniques are utilized to achieve a real-time perception of the object in the sea environment. Second, detailed path planning strategies are illustrated to plan the easily reachable path for different missions, and the classic guidance and heading controller are adopted to implement the path following algorithm. Subsequently, these autonomy algorithms run in the high-level computer and render the actuator commands for the low-level embedded control system. Finally, sea trials of the USV are conducted by attending the 2020 Zhuhai Wanshan International Intelligent Vessel Competition (IIVC) in Dong Ao Island of South China Sea. The USV accomplish three missions: 1) path following, 2) navigating around the obstacle, and 3) rescuing the drowning. Sea trial results verify the autonomy of the USV in terms of the achieved performances.
{"title":"DEVELOPMENT OF USV AUTONOMY: ARCHITECTURE, IMPLEMENTATION AND SEA TRIALS","authors":"Chuan Liu, Xianbo Xiang, Jian Huang, Shaolong Yang, Zhang Shaoze, Xiang Su, Yunfei Zhang","doi":"10.21278/brod73105","DOIUrl":"https://doi.org/10.21278/brod73105","url":null,"abstract":"This paper presents the development of autonomy capability for an unmanned surface vehicle (USV). The development mainly focuses on the high-level autonomy on perception, path planning, guidance and control to achieve real sea applications of the USV. First, visual recognition and point cloud data processing techniques are utilized to achieve a real-time perception of the object in the sea environment. Second, detailed path planning strategies are illustrated to plan the easily reachable path for different missions, and the classic guidance and heading controller are adopted to implement the path following algorithm. Subsequently, these autonomy algorithms run in the high-level computer and render the actuator commands for the low-level embedded control system. Finally, sea trials of the USV are conducted by attending the 2020 Zhuhai Wanshan International Intelligent Vessel Competition (IIVC) in Dong Ao Island of South China Sea. The USV accomplish three missions: 1) path following, 2) navigating around the obstacle, and 3) rescuing the drowning. Sea trial results verify the autonomy of the USV in terms of the achieved performances.","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48380126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Andalusian Agency of Energy has identified three areas of major interest for harnessing wave energy, in their plan of “Marine Energy and Energy Resources of Andalusia”. One of these areas is located on the Atlantic coast, the bay of Cádiz. Considering this initial interest, the objective of this work is to carry out an evaluation of the performance provided by various technologies of wave energy conversion in the bay of Cádiz. The data for the wave climate in the target area are obtained from the Spanish Agency Puertos del Estado. Diagrams for bivariate distributions of the sea states occurrences, defined by the significant wave height and the energy period, are shown. On this basis, the output of nine different technologies for the conversion of wave energy is assessed in the reference locations in the bay of Cádiz. According to the results obtained, it can be said that the bay of Cádiz is a suitable place for wave energy extraction.
安达卢西亚能源局在其“安达卢西娅海洋能源和能源资源”计划中确定了利用波浪能的三个主要兴趣领域。其中一个地区位于大西洋沿岸的加的斯湾。考虑到这一最初的兴趣，这项工作的目标是对加的斯湾波浪能转换的各种技术所提供的性能进行评估。目标地区的波浪气候数据来自西班牙Puertos del Estado机构。显示了由有效波高和能量周期定义的海况出现的双变量分布图。在此基础上，在加的斯湾的参考地点评估了九种不同的波浪能转换技术的输出。根据获得的结果，可以说加的斯湾是提取波浪能量的合适地点。
{"title":"EVALUATION OF VARIOUS WAVE ENERGY CONVERTERS IN THE BAY OF CÁDIZ","authors":"M. J. Legaz, Carlos Soares","doi":"10.21278/brod73104","DOIUrl":"https://doi.org/10.21278/brod73104","url":null,"abstract":"The Andalusian Agency of Energy has identified three areas of major interest for harnessing wave energy, in their plan of “Marine Energy and Energy Resources of Andalusia”. One of these areas is located on the Atlantic coast, the bay of Cádiz. Considering this initial interest, the objective of this work is to carry out an evaluation of the performance provided by various technologies of wave energy conversion in the bay of Cádiz. The data for the wave climate in the target area are obtained from the Spanish Agency Puertos del Estado. Diagrams for bivariate distributions of the sea states occurrences, defined by the significant wave height and the energy period, are shown. On this basis, the output of nine different technologies for the conversion of wave energy is assessed in the reference locations in the bay of Cádiz. According to the results obtained, it can be said that the bay of Cádiz is a suitable place for wave energy extraction.","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43660997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. Dai, Yunbo Li, Jiaye Gong, Zheng Fu, Ang Li, Dapeng Zhang
This paper applies Reynolds-averaged Navier-Stokes (RANS) method to study propulsion performance in head and oblique waves. Finite volume method (FVM) is employed to discretize the governing equations and SST k-ω model is used for modeling the turbulent flow. The free surface is solved by volume of fluid (VOF) method. Sliding mesh technique is used to enable rotation of propeller. Propeller open water curves are determined by propeller open water simulations. Calm water resistance and wave added resistances are obtained from towing computations without propeller. Self-propulsion simulations in calm water and waves with varying loads are performed to obtain self-propulsion point and thrust identify method is use to predict propulsive factors. Regular head waves with wavelengths varying from 0.6 to 1.4 times the length of ship and oblique waves with incident directions varying from 0° to 360° are considered. The influence of waves on propulsive factors, including thrust deduction and wake fraction, open water, relative rotative, hull and propulsive efficiencies are discussed.
{"title":"NUMERICAL STUDY ON PROPULSIVE FACTORS IN REGULAR HEAD AND OBLIQUE WAVES","authors":"K. Dai, Yunbo Li, Jiaye Gong, Zheng Fu, Ang Li, Dapeng Zhang","doi":"10.21278/brod73103","DOIUrl":"https://doi.org/10.21278/brod73103","url":null,"abstract":"This paper applies Reynolds-averaged Navier-Stokes (RANS) method to study propulsion performance in head and oblique waves. Finite volume method (FVM) is employed to discretize the governing equations and SST k-ω model is used for modeling the turbulent flow. The free surface is solved by volume of fluid (VOF) method. Sliding mesh technique is used to enable rotation of propeller. Propeller open water curves are determined by propeller open water simulations. Calm water resistance and wave added resistances are obtained from towing computations without propeller. Self-propulsion simulations in calm water and waves with varying loads are performed to obtain self-propulsion point and thrust identify method is use to predict propulsive factors. Regular head waves with wavelengths varying from 0.6 to 1.4 times the length of ship and oblique waves with incident directions varying from 0° to 360° are considered. The influence of waves on propulsive factors, including thrust deduction and wake fraction, open water, relative rotative, hull and propulsive efficiencies are discussed.","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49645259","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A study about the requirements and cargo transportation demand in the Black Sea as part of a multimodal transportation frame is performed, estimating the potential need of a ship fleet of multipurpose ships. The study performs conceptual multipurpose vessel design and fleet sizing using the long-time experience and statistics in defining main dimensions of the ship and her hull form, resistance and propulsion, weights, stability, free-board, seakeeping and manoeuvrability, capital, operational and decommissioning expenditure, where the optimal design solution is obtained based on the energy efficiency, shipbuilding, operation, and resale costs at the end of the service life. A discussion about possible applications of a different fleet of ship sizes in improving the cargo transportation efficiency considers the vessel's typical operational profile in such a way to maximise the economic impact conditional of the unsteady cargo flow and environmental impact.
{"title":"MULTIPURPOSE VESSEL FLEET FOR SHORT BLACK SEA SHIPPING THROUGH MULTIMODAL TRANSPORT CORRIDORS","authors":"P. Georgiev, Y. Garbatov","doi":"10.21278/brod72405","DOIUrl":"https://doi.org/10.21278/brod72405","url":null,"abstract":"A study about the requirements and cargo transportation demand in the Black Sea as part of a multimodal transportation frame is performed, estimating the potential need of a ship fleet of multipurpose ships. The study performs conceptual multipurpose vessel design and fleet sizing using the long-time experience and statistics in defining main dimensions of the ship and her hull form, resistance and propulsion, weights, stability, free-board, seakeeping and manoeuvrability, capital, operational and decommissioning expenditure, where the optimal design solution is obtained based on the energy efficiency, shipbuilding, operation, and resale costs at the end of the service life. A discussion about possible applications of a different fleet of ship sizes in improving the cargo transportation efficiency considers the vessel's typical operational profile in such a way to maximise the economic impact conditional of the unsteady cargo flow and environmental impact.","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44302663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Manuel Naveiro, M. Romero Gómez, Ignacio Arias Fernández, Javier Romero Gomez
This paper aims to review regasification technology installed in Floating Storage Regasification Units (FSRUs) and the potential offered by the exploitation of cold energy from liquefied natural gas (LNG) in these vessels. The assessment describes the main characteristics of regasification systems along with their respective advantages and limitations. Regasification systems in direct exchange (seawater and steam) and systems with intermediate fluids that use propane or water-glycol in the heat transfer process are studied. In recent years, water-glycol systems have cornered the market. The mixture, besides reducing the risk of freezing, is non-flammable, economical and highly available. Thermodynamic analysis of the regasification process shows that LNG cold energy is the main source of residual energy in these vessels; the specific energy and exergy content is more than double that of engine exhaust gases. Exploitation of this cold energy in power cycles could significantly reduce FSRUs harmful emissions and electrical energy could even be exported to shore. The organic Rankine cycle technology is the most well-known and widely studied, although scientific literature is scarce and there is a need to propose new regasification systems with cold energy exploitation that can be adopted on these vessels.
{"title":"EXPLOITATION OF LIQUEFIED NATURAL GAS COLD ENERGY IN FLOATING STORAGE REGASIFICATION UNITS","authors":"Manuel Naveiro, M. Romero Gómez, Ignacio Arias Fernández, Javier Romero Gomez","doi":"10.21278/brod72404","DOIUrl":"https://doi.org/10.21278/brod72404","url":null,"abstract":"This paper aims to review regasification technology installed in Floating Storage Regasification Units (FSRUs) and the potential offered by the exploitation of cold energy from liquefied natural gas (LNG) in these vessels. The assessment describes the main characteristics of regasification systems along with their respective advantages and limitations. Regasification systems in direct exchange (seawater and steam) and systems with intermediate fluids that use propane or water-glycol in the heat transfer process are studied. In recent years, water-glycol systems have cornered the market. The mixture, besides reducing the risk of freezing, is non-flammable, economical and highly available. Thermodynamic analysis of the regasification process shows that LNG cold energy is the main source of residual energy in these vessels; the specific energy and exergy content is more than double that of engine exhaust gases. Exploitation of this cold energy in power cycles could significantly reduce FSRUs harmful emissions and electrical energy could even be exported to shore. The organic Rankine cycle technology is the most well-known and widely studied, although scientific literature is scarce and there is a need to propose new regasification systems with cold energy exploitation that can be adopted on these vessels.","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45267115","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
N. Ivanovsky, S. Chernyi, S. Sokolov, A. Zhilenkov, A. Zinchenko
The problems of developing the risk assessment methods to estimate the level of safety of the vessel under the current conditions on a planned route before staring the pilotage as well as to make the decision on the beginning or suspension of pilotage in order to increase the level of navigational safety are discussed in the paper. Moreover, the application of the research results will reduce the affect of the human factor in decision-making in tasks related to the sea-going vessel’s operation. The developed method for the quantitative assessment of navigational risks will improve the safety of ship’s pilotage. It can also be applied in the decision-making support systems for the navigator in case of collision avoidance actions. The research results presented in this paper can be used to create automatic control systems.
{"title":"ALGORITHM DESIGN FOR SHIP’S STEERING WITH SPECIFIED LIMITATIONS UNDER VARIOUS WEATHER CONDITIONS","authors":"N. Ivanovsky, S. Chernyi, S. Sokolov, A. Zhilenkov, A. Zinchenko","doi":"10.21278/brod72402","DOIUrl":"https://doi.org/10.21278/brod72402","url":null,"abstract":"The problems of developing the risk assessment methods to estimate the level of safety of the vessel under the current conditions on a planned route before staring the pilotage as well as to make the decision on the beginning or suspension of pilotage in order to increase the level of navigational safety are discussed in the paper. Moreover, the application of the research results will reduce the affect of the human factor in decision-making in tasks related to the sea-going vessel’s operation. The developed method for the quantitative assessment of navigational risks will improve the safety of ship’s pilotage. It can also be applied in the decision-making support systems for the navigator in case of collision avoidance actions. The research results presented in this paper can be used to create automatic control systems.","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47685951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Rodríguez, M. Lamas, Juan de Dios Rodríguez, Claudio Caccia
The present manuscript describes a computational model employed to characterize the performance and emissions of a commercial marine diesel engine. This model analyzes several pre-injection parameters, such as starting instant, quantity, and duration. The goal is to reduce nitrogen oxides (NOx), as well as its effect on emissions and consumption. Since some of the parameters considered have opposite effects on the results, the present work proposes a MCDM (Multiple-Criteria Decision Making) methodology to determine the most adequate pre-injection configuration. An important issue in MCDM models is the data normalization process. This operation is necessary to convert the available data into a non-dimensional common scale, thus allowing ranking and rating alternatives. It is important to select a suitable normalization technique, and several methods exist in the literature. This work considers five well-known normalization procedures: linear max, linear max-min, linear sum, vector, and logarithmic normalization. As to the solution technique, the study considers three MCDM models: WSM (Weighted Sum Method), WPM (Weighted Product Method) and TOPSIS (Technique for Order Preference by Similarity to Ideal Solution). The linear max, linear sum, vector, and logarithmic normalization procedures brought the same result: -22º CA ATDC pre-injection starting instant, 25% pre-injection quantity and 1-2º CA pre-injection duration. Nevertheless, the linear max min normalization procedure provided a result, which is different from the others and not recommended.
{"title":"ANALYSIS OF THE PRE-INJECTION CONFIGURATION IN A MARINE ENGINE THROUGH SEVERAL MCDM TECHNIQUES","authors":"C. Rodríguez, M. Lamas, Juan de Dios Rodríguez, Claudio Caccia","doi":"10.21278/brod72401","DOIUrl":"https://doi.org/10.21278/brod72401","url":null,"abstract":"The present manuscript describes a computational model employed to characterize the performance and emissions of a commercial marine diesel engine. This model analyzes several pre-injection parameters, such as starting instant, quantity, and duration. The goal is to reduce nitrogen oxides (NOx), as well as its effect on emissions and consumption. Since some of the parameters considered have opposite effects on the results, the present work proposes a MCDM (Multiple-Criteria Decision Making) methodology to determine the most adequate pre-injection configuration. An important issue in MCDM models is the data normalization process. This operation is necessary to convert the available data into a non-dimensional common scale, thus allowing ranking and rating alternatives. It is important to select a suitable normalization technique, and several methods exist in the literature. This work considers five well-known normalization procedures: linear max, linear max-min, linear sum, vector, and logarithmic normalization. As to the solution technique, the study considers three MCDM models: WSM (Weighted Sum Method), WPM (Weighted Product Method) and TOPSIS (Technique for Order Preference by Similarity to Ideal Solution). The linear max, linear sum, vector, and logarithmic normalization procedures brought the same result: -22º CA ATDC pre-injection starting instant, 25% pre-injection quantity and 1-2º CA pre-injection duration. Nevertheless, the linear max min normalization procedure provided a result, which is different from the others and not recommended.","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47450077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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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