Abstract One potential solution for reducing carbon dioxide emissions from ships and meeting the Energy Efficiency Existing Ship Index (EEXI) requirements is to use a hybrid propulsion system that combines liquid hydrogen and liquefied natural gas fuels. To improve energy efficiency for diesel-electric dual-fuel ship propulsion systems, an engine power limitation system can also be used. This paper examines the potential use of these systems with regard to several factors, including compliance with EEXI standards set by the International Maritime Organization, fuel ratio optimisation, installation requirements, and economic feasibility. As a case study, an LNG carrier is analysed, with dual-fuel diesel-electric and two hybrid systems adjusted to meet IMO-EEXI requirements with engine power limitation percentages of 25%, 0% (hybrid option 1), and 15% (hybrid option 2), respectively. From an economic standpoint, the liquid hydrogen-based system has competitive costs compared to the dual-fuel diesel-electric system, with costs of 2.1 and 2.5 dollars per kilogram for hybrid system options 1 and 2, respectively.
{"title":"Economic Analysis and the EEXI Reduction Potential of Parallel Hybrid Dual-Fuel Engine‒Fuel Cell Propulsion Systems for LNG Carriers","authors":"Nader R. Ammar, Majid Almas, Qusai Nahas","doi":"10.2478/pomr-2023-0039","DOIUrl":"https://doi.org/10.2478/pomr-2023-0039","url":null,"abstract":"Abstract One potential solution for reducing carbon dioxide emissions from ships and meeting the Energy Efficiency Existing Ship Index (EEXI) requirements is to use a hybrid propulsion system that combines liquid hydrogen and liquefied natural gas fuels. To improve energy efficiency for diesel-electric dual-fuel ship propulsion systems, an engine power limitation system can also be used. This paper examines the potential use of these systems with regard to several factors, including compliance with EEXI standards set by the International Maritime Organization, fuel ratio optimisation, installation requirements, and economic feasibility. As a case study, an LNG carrier is analysed, with dual-fuel diesel-electric and two hybrid systems adjusted to meet IMO-EEXI requirements with engine power limitation percentages of 25%, 0% (hybrid option 1), and 15% (hybrid option 2), respectively. From an economic standpoint, the liquid hydrogen-based system has competitive costs compared to the dual-fuel diesel-electric system, with costs of 2.1 and 2.5 dollars per kilogram for hybrid system options 1 and 2, respectively.","PeriodicalId":49681,"journal":{"name":"Polish Maritime Research","volume":"2013 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135688301","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 development of ship motion control systems, software simulations or scale model experiments in pools or open water are very often carried out in the verification and testing stages. This paper describes the process of building a software wave simulator based on data gathered on the Silm Lake near Iława, Poland, where scale ship models are used for research and training. The basis of the simulator structure is a set of shaping filters fed with Gaussian white noise. These filters are built in the form of transfer functions generating irregular wave signals for different input wind forces. To enable simulation of a wide range of wind speeds, nonlinear interpolation is used. The lake wave simulation method presented in this paper fills a gap in current research, and enables accurate modelling of characteristic environmental disturbances on a small lake for motion control experiments of scale model ships.
{"title":"Modelling of Lake Waves to Simulate Environmental Disturbance to a Scale Ship Model","authors":"Andrzej Rak, Anna Miller","doi":"10.2478/pomr-2023-0035","DOIUrl":"https://doi.org/10.2478/pomr-2023-0035","url":null,"abstract":"Abstract In the development of ship motion control systems, software simulations or scale model experiments in pools or open water are very often carried out in the verification and testing stages. This paper describes the process of building a software wave simulator based on data gathered on the Silm Lake near Iława, Poland, where scale ship models are used for research and training. The basis of the simulator structure is a set of shaping filters fed with Gaussian white noise. These filters are built in the form of transfer functions generating irregular wave signals for different input wind forces. To enable simulation of a wide range of wind speeds, nonlinear interpolation is used. The lake wave simulation method presented in this paper fills a gap in current research, and enables accurate modelling of characteristic environmental disturbances on a small lake for motion control experiments of scale model ships.","PeriodicalId":49681,"journal":{"name":"Polish Maritime Research","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135688307","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}
Lech Rowiński, Thanh Hai Truong, Phuoc Quy Phong Nguyen
Abstract The proposal of a system for the safe recovery of unexploded ordnance (UXO), chemical weapons (CW) and chemical warfare agents (CWA) dumped at sea mainly after WWI and WWII is described in this work. The proposed solution addresses the tasks required to neutralise thousands of tons of dumped material and the currently available solutions and proposed ideas. Requirements concerning the features of a recovery system are defined and scrutinised, these being intended to ensure the safety of this phase of the UXO/CW neutralisation process. To meet this requirement, the concept of a remotely operated, two-component working size underwater vehicle is proposed, supplemented by a properly sized and outfitted surface platform that is an important part of the recovery system. Finally, the basic components of the proposed system configuration are characterised, together with their functions during the recovery of dangerous CWA-related objects.
{"title":"Toward Safe and Efficient Recovery of Gas Munitions Dumped at Sea","authors":"Lech Rowiński, Thanh Hai Truong, Phuoc Quy Phong Nguyen","doi":"10.2478/pomr-2023-0051","DOIUrl":"https://doi.org/10.2478/pomr-2023-0051","url":null,"abstract":"Abstract The proposal of a system for the safe recovery of unexploded ordnance (UXO), chemical weapons (CW) and chemical warfare agents (CWA) dumped at sea mainly after WWI and WWII is described in this work. The proposed solution addresses the tasks required to neutralise thousands of tons of dumped material and the currently available solutions and proposed ideas. Requirements concerning the features of a recovery system are defined and scrutinised, these being intended to ensure the safety of this phase of the UXO/CW neutralisation process. To meet this requirement, the concept of a remotely operated, two-component working size underwater vehicle is proposed, supplemented by a properly sized and outfitted surface platform that is an important part of the recovery system. Finally, the basic components of the proposed system configuration are characterised, together with their functions during the recovery of dangerous CWA-related objects.","PeriodicalId":49681,"journal":{"name":"Polish Maritime Research","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135688517","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 degradation of structures under the influence of a marine environment tends to be rapid and disruptive compared to that of structures that are far away from these influences. Efforts to consider these impacts in the design phase are increasing, with a view to the construction of more sustainable structures. However, experimental data from which designers and builders can benefit cannot be found in the relevant literature, especially when it comes to the effects of composite degradation. In this study, we experimentally investigate the combined effects of degradation factors such as a drying-wetting cycle, the shape of the structure, the variety of materials used in the structure, and the differences in the manufacturing of the materials . The structure chosen as an example is a hybrid structural double lap joint composed of epoxy resin, fibreglass composite, and steel, which is widely used in ship structures. The experiments considered four aging periods (zero, 30, 60 and 90 days) under a wet-dry cycle in a programmable corrosion chamber, two overlap lengths (short and long), two surface roughnesses of the steel parts (50 and 90 μm), and two surface preparation alternatives (uncoated and coated with epoxy primer). The synergistic effects of these parameters on the tensile strength, deformation and toughness of the joints were evaluated, and suggestions are made for ship designers. The attention of interested parties, and particularly ship designers, is drawn to the comparative effects of these degradation agents on performance.
{"title":"Synergistic Performance Degradation of Marine Structural Elements: Case Study of Polymer-Based Composite and Steel Hybrid Double Lap Joints","authors":"Halis Haluk Baykal, Gokdeniz Neser","doi":"10.2478/pomr-2023-0044","DOIUrl":"https://doi.org/10.2478/pomr-2023-0044","url":null,"abstract":"Abstract The degradation of structures under the influence of a marine environment tends to be rapid and disruptive compared to that of structures that are far away from these influences. Efforts to consider these impacts in the design phase are increasing, with a view to the construction of more sustainable structures. However, experimental data from which designers and builders can benefit cannot be found in the relevant literature, especially when it comes to the effects of composite degradation. In this study, we experimentally investigate the combined effects of degradation factors such as a drying-wetting cycle, the shape of the structure, the variety of materials used in the structure, and the differences in the manufacturing of the materials . The structure chosen as an example is a hybrid structural double lap joint composed of epoxy resin, fibreglass composite, and steel, which is widely used in ship structures. The experiments considered four aging periods (zero, 30, 60 and 90 days) under a wet-dry cycle in a programmable corrosion chamber, two overlap lengths (short and long), two surface roughnesses of the steel parts (50 and 90 μm), and two surface preparation alternatives (uncoated and coated with epoxy primer). The synergistic effects of these parameters on the tensile strength, deformation and toughness of the joints were evaluated, and suggestions are made for ship designers. The attention of interested parties, and particularly ship designers, is drawn to the comparative effects of these degradation agents on performance.","PeriodicalId":49681,"journal":{"name":"Polish Maritime Research","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135688191","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 Modernisation of marine power plants in the transport vessel fleet to satisfy the requirements of the International Maritime Organization is an urgent scientific and technical problem. Currently, the use of catalytic selective filters, dry and wet scrubber systems and exhaust gas recirculation for marine diesel engines is widely used for this purpose. An analysis of the use of ejection gas-air coolers is presented as an additional method of emission reduction. However, the use of such device does not neutralise the harmful emissions of power plant engines, but only increases the volume concentration of their exhaust gases. But this will help to increase the efficiency of dispersion of harmful emissions, by reducing the concentration of harmful emissions to values not exceeding the maximum permissible concentrations. Its efficiency depends on the load mode of the diesel engine. It is found that the initial concentration of harmful substances in combustion products due to their dilution with fresh air at 100% engine load is reduced by about 50%. The values of the reduction of the concentration and temperature of exhaust gases with the reduction of the engine load to 75% and 50% depending on the louvre angle are obtained. It is proved that ejection gas-air coolers can be an effective additional means for compliance with modern environmental parameters, especially when vessels are in special areas of the world’s oceans.
{"title":"Determination of Rational Design Values for Gas-Air Coolers Components of Exhaust Gases of Marine Power Plants","authors":"Svitlana Kuznetsova, Valerii Kuznetsov, Andrii Voloshyn","doi":"10.2478/pomr-2023-0041","DOIUrl":"https://doi.org/10.2478/pomr-2023-0041","url":null,"abstract":"Abstract Modernisation of marine power plants in the transport vessel fleet to satisfy the requirements of the International Maritime Organization is an urgent scientific and technical problem. Currently, the use of catalytic selective filters, dry and wet scrubber systems and exhaust gas recirculation for marine diesel engines is widely used for this purpose. An analysis of the use of ejection gas-air coolers is presented as an additional method of emission reduction. However, the use of such device does not neutralise the harmful emissions of power plant engines, but only increases the volume concentration of their exhaust gases. But this will help to increase the efficiency of dispersion of harmful emissions, by reducing the concentration of harmful emissions to values not exceeding the maximum permissible concentrations. Its efficiency depends on the load mode of the diesel engine. It is found that the initial concentration of harmful substances in combustion products due to their dilution with fresh air at 100% engine load is reduced by about 50%. The values of the reduction of the concentration and temperature of exhaust gases with the reduction of the engine load to 75% and 50% depending on the louvre angle are obtained. It is proved that ejection gas-air coolers can be an effective additional means for compliance with modern environmental parameters, especially when vessels are in special areas of the world’s oceans.","PeriodicalId":49681,"journal":{"name":"Polish Maritime Research","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135688203","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}
Yiqun Lin, Jie Lu, Boyang Li, Yajing Li, Qingyong Yang
Abstract A CO 2 boiled off gas (CO 2 BOG) reliquefaction system using liquid ammonia cold energy is designed to solve the problems of fuel cold energy waste and the large power consumption of the compressor in the process of CO 2 BOG reliquefaction on an ammonia-powered CO 2 carrier. Aspen HYSYS is used to simulate the calculation, and it is found that the system has lower power consumption than the existing reliquefaction method. The temperature of the heat exchanger heater-1 heat flow outlet node (node C-4) is optimised, and it is found that, with the increase of the node C-4 temperature, the power consumption of the compressor gradually increases, and the liquefaction fraction of CO 2 BOG gradually decreases. Under 85% conditions, when the ambient temperature is 0°C and the temperature of node C-4 is -9°C, the liquid fraction of CO 2 BOG reaches the maximum, which is 74.46%, and the power of Compressor-1 is the minimum, which is 40.90 kW. According to this, the optimum temperature of node C-4 under various working conditions is determined. The exergy efficiency model is established, in an 85% ship working condition with the ambient temperature of 40°C, and the exergy efficiency of the system is the maximum, reaching 59.58%. Therefore, the CO 2 BOG reliquefaction system proposed in this study could realise effective utilisation of liquid ammonia cold energy.
{"title":"Application of Fuel Cold Energy in CO<sub>2</sub> Bog Reliquefaction System on Ammonia-Powered CO<sub>2</sub> Carrier","authors":"Yiqun Lin, Jie Lu, Boyang Li, Yajing Li, Qingyong Yang","doi":"10.2478/pomr-2023-0036","DOIUrl":"https://doi.org/10.2478/pomr-2023-0036","url":null,"abstract":"Abstract A CO 2 boiled off gas (CO 2 BOG) reliquefaction system using liquid ammonia cold energy is designed to solve the problems of fuel cold energy waste and the large power consumption of the compressor in the process of CO 2 BOG reliquefaction on an ammonia-powered CO 2 carrier. Aspen HYSYS is used to simulate the calculation, and it is found that the system has lower power consumption than the existing reliquefaction method. The temperature of the heat exchanger heater-1 heat flow outlet node (node C-4) is optimised, and it is found that, with the increase of the node C-4 temperature, the power consumption of the compressor gradually increases, and the liquefaction fraction of CO 2 BOG gradually decreases. Under 85% conditions, when the ambient temperature is 0°C and the temperature of node C-4 is -9°C, the liquid fraction of CO 2 BOG reaches the maximum, which is 74.46%, and the power of Compressor-1 is the minimum, which is 40.90 kW. According to this, the optimum temperature of node C-4 under various working conditions is determined. The exergy efficiency model is established, in an 85% ship working condition with the ambient temperature of 40°C, and the exergy efficiency of the system is the maximum, reaching 59.58%. Therefore, the CO 2 BOG reliquefaction system proposed in this study could realise effective utilisation of liquid ammonia cold energy.","PeriodicalId":49681,"journal":{"name":"Polish Maritime Research","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135687901","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}
Nguyen Dang Khoa Pham, Gia Huy Dinh, Hoang Thai Pham, Janusz Kozak, Hoang Phuong Nguyen
Abstract The global supply chain has been growing strongly in recent years. This development brings many benefits to the economy, society, and human resources in each country but also causes a large number of concerns related to the environment since traditional logistics activities in the supply chain have been releasing a significant amount of emissions. For that reason, many solutions have been proposed to deal with these environmental pollution problems. Among these, three promising solutions are expected to completely solve environmental problems in every supply chain: (i) Application of blockchain in the supply chain, (ii) Use of renewable energy and alternative fuels, and (iii) Design of a closed supply chain. However, it seems to lack a comprehensive study of these solutions aiming to overcome the drawbacks of traditional logistics. Indeed, this work focuses on analyzing and evaluating the three above-mentioned solutions and the impacts of each solution on solving problems related to traditional logistics. More importantly, this work also identifies critical factors and challenges such as policies, laws, awareness, and risks that are found to be remarkable difficulties in the shifting progress of traditional logistics to green logistics. Finally, directions for developing and deploying green solutions to the logistics, supply chain, and shipping sectors toward decarbonization strategies and net-zero goals are discussed in detail.
{"title":"Role of Green Logistics in the Construction of Sustainable Supply Chains","authors":"Nguyen Dang Khoa Pham, Gia Huy Dinh, Hoang Thai Pham, Janusz Kozak, Hoang Phuong Nguyen","doi":"10.2478/pomr-2023-0052","DOIUrl":"https://doi.org/10.2478/pomr-2023-0052","url":null,"abstract":"Abstract The global supply chain has been growing strongly in recent years. This development brings many benefits to the economy, society, and human resources in each country but also causes a large number of concerns related to the environment since traditional logistics activities in the supply chain have been releasing a significant amount of emissions. For that reason, many solutions have been proposed to deal with these environmental pollution problems. Among these, three promising solutions are expected to completely solve environmental problems in every supply chain: (i) Application of blockchain in the supply chain, (ii) Use of renewable energy and alternative fuels, and (iii) Design of a closed supply chain. However, it seems to lack a comprehensive study of these solutions aiming to overcome the drawbacks of traditional logistics. Indeed, this work focuses on analyzing and evaluating the three above-mentioned solutions and the impacts of each solution on solving problems related to traditional logistics. More importantly, this work also identifies critical factors and challenges such as policies, laws, awareness, and risks that are found to be remarkable difficulties in the shifting progress of traditional logistics to green logistics. Finally, directions for developing and deploying green solutions to the logistics, supply chain, and shipping sectors toward decarbonization strategies and net-zero goals are discussed in detail.","PeriodicalId":49681,"journal":{"name":"Polish Maritime Research","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135688520","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 highlight model is widely used as a simple and convenient method in the radar field but its accuracy is not high. Based on the traditional highlight model, the algorithm has been improved to address the acoustic scattering problems of underwater vehicles with more complex line shapes. The basic idea is to partition the model into micro-bodies to calculate the scattered sound pressure, consider the phase interference of each part, and then synthesise the scattered sound pressure to approximate the target’s actual shape. A computational model of the wedge-shaped convex structure on the back of the underwater vehicles is developed using a highlight model of a trapezoidal plate. The results of the calculations using the highlight model approach are consistent with those of the planar element method. Utilising the modified highlight model method, the accuracy of acoustic scattering characteristics calculations for the stern and overall structures of underwater vehicles has proven satisfactory. Finally, fast acoustic scattering prediction software is developed for underwater vehicles, enabling the calculation of the acoustic scattering characteristics for individual structures, combined structures, and coated silent tiles. This software provides algorithmic support for the fast prediction of the acoustic stealth performance of underwater vehicles.
{"title":"Research on the Modified Echo Highlight Model for Underwater Vehicles with Combined Structures","authors":"Xin Xie, Fanghua Liu, Guangwen Jin, Jinwei Liu, Cong Xu, Zilong Peng","doi":"10.2478/pomr-2023-0049","DOIUrl":"https://doi.org/10.2478/pomr-2023-0049","url":null,"abstract":"Abstract The highlight model is widely used as a simple and convenient method in the radar field but its accuracy is not high. Based on the traditional highlight model, the algorithm has been improved to address the acoustic scattering problems of underwater vehicles with more complex line shapes. The basic idea is to partition the model into micro-bodies to calculate the scattered sound pressure, consider the phase interference of each part, and then synthesise the scattered sound pressure to approximate the target’s actual shape. A computational model of the wedge-shaped convex structure on the back of the underwater vehicles is developed using a highlight model of a trapezoidal plate. The results of the calculations using the highlight model approach are consistent with those of the planar element method. Utilising the modified highlight model method, the accuracy of acoustic scattering characteristics calculations for the stern and overall structures of underwater vehicles has proven satisfactory. Finally, fast acoustic scattering prediction software is developed for underwater vehicles, enabling the calculation of the acoustic scattering characteristics for individual structures, combined structures, and coated silent tiles. This software provides algorithmic support for the fast prediction of the acoustic stealth performance of underwater vehicles.","PeriodicalId":49681,"journal":{"name":"Polish Maritime Research","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135688701","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 a continuation of research carried out to determine the effect of input parameters (changes in engine structure parameters) on selected output parameters (diagnostic measures), based on quickly changing exhaust gas temperature. A method of determining the simultaneous influence of two input factors (the structure parameter and the engine load) on one output factor was presented, as well as an evaluation of which of the analysed input factors has a stronger influence on the output parameter. The article presents the stages of the experimental research conducted and statistical inference based on the results. Three changing parameters for the structure were reviewed: the active cross-sectional area of the inlet air channel, the injector opening pressure and the compression ratio. Based on the quickly changing temperatures of the exhaust gases, three diagnostic measures were defined and subjected to statistical tests. The following data were averaged over one cycle for a 4-stroke engine operation: the intensity of changes, the specific enthalpy and the peak-to-peak value of the exhaust gas temperature. The results of the two-factor analysis are presented. Conclusions on the analysis are given and a criterion for the selection of a diagnostic measure, depending on the analysed parameter of the structural design of the diesel engine, is proposed. The previous part of the article presented the results of the first stage of the elimination study: the one-factor statistical analysis (randomised complete plan). This paper presents the results of the second stage of the studies: two-factor analysis (block randomised plan), where the significance of the effect of changing the values of the structural parameters on the diagnostic measures were analysed in the background of a variable engine load. The next (third) part will present the results of the calculations and analysis of the interaction coefficient of significance.
{"title":"Diagnostic Analysis of Exhaust Gas with A Quick-Changing Temperature from a Marine Diesel Engine Part II / Two Factor Analysis","authors":"Patrycja Puzdrowska","doi":"10.2478/pomr-2023-0042","DOIUrl":"https://doi.org/10.2478/pomr-2023-0042","url":null,"abstract":"Abstract The article presents a continuation of research carried out to determine the effect of input parameters (changes in engine structure parameters) on selected output parameters (diagnostic measures), based on quickly changing exhaust gas temperature. A method of determining the simultaneous influence of two input factors (the structure parameter and the engine load) on one output factor was presented, as well as an evaluation of which of the analysed input factors has a stronger influence on the output parameter. The article presents the stages of the experimental research conducted and statistical inference based on the results. Three changing parameters for the structure were reviewed: the active cross-sectional area of the inlet air channel, the injector opening pressure and the compression ratio. Based on the quickly changing temperatures of the exhaust gases, three diagnostic measures were defined and subjected to statistical tests. The following data were averaged over one cycle for a 4-stroke engine operation: the intensity of changes, the specific enthalpy and the peak-to-peak value of the exhaust gas temperature. The results of the two-factor analysis are presented. Conclusions on the analysis are given and a criterion for the selection of a diagnostic measure, depending on the analysed parameter of the structural design of the diesel engine, is proposed. The previous part of the article presented the results of the first stage of the elimination study: the one-factor statistical analysis (randomised complete plan). This paper presents the results of the second stage of the studies: two-factor analysis (block randomised plan), where the significance of the effect of changing the values of the structural parameters on the diagnostic measures were analysed in the background of a variable engine load. The next (third) part will present the results of the calculations and analysis of the interaction coefficient of significance.","PeriodicalId":49681,"journal":{"name":"Polish Maritime Research","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135687818","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}
Long Zheng, Shunhuai Chen, Xinyu Chen, Shengchen Ji
Abstract In this study, an effective parametric 3D geometry model of a propeller was established with the aid of reverse engineering. The goal is to reduce the free parameters while automating the modelling of the propeller. The process of building the parametric model begins by generating an initial point cloud by defining the feature matrix associated with the propeller blade profile shape. Subsequently, the initial point cloud is deformed and refined by the deformation feature matrix and resampling. Finally, a 3D geometry model of the propeller is generated by surface reconstruction. The model can be built automatically by interactively modifying the feature matrices. Two numerical analyses illustrate the performance of the parametric 3D geometry model. Specifically, two propellers are constructed using the proposed model to estimate the shape error between the reconstructed propellers and the original offset of the propellers. These propellers are selected as research objects to determine the hydrodynamic performance error between the propeller constructed by the proposed model and a benchmark propeller. According to the results of the numerical study, the parametric 3D geometry model can precisely reconstruct the aforementioned geometry within a valid error range. The hydrodynamic error analysis demonstrates that the geometric inaccuracy from the reconstructed model has less impact on the propeller performance. This indicates that the model described in this study is generalised and robust. Moreover, some uncommon propeller CAD models were generated in batches using the parametric 3D geometry model.
{"title":"Reverse Engineering-Inspired Parametric 3D Geometry Model of Marine Propeller","authors":"Long Zheng, Shunhuai Chen, Xinyu Chen, Shengchen Ji","doi":"10.2478/pomr-2023-0037","DOIUrl":"https://doi.org/10.2478/pomr-2023-0037","url":null,"abstract":"Abstract In this study, an effective parametric 3D geometry model of a propeller was established with the aid of reverse engineering. The goal is to reduce the free parameters while automating the modelling of the propeller. The process of building the parametric model begins by generating an initial point cloud by defining the feature matrix associated with the propeller blade profile shape. Subsequently, the initial point cloud is deformed and refined by the deformation feature matrix and resampling. Finally, a 3D geometry model of the propeller is generated by surface reconstruction. The model can be built automatically by interactively modifying the feature matrices. Two numerical analyses illustrate the performance of the parametric 3D geometry model. Specifically, two propellers are constructed using the proposed model to estimate the shape error between the reconstructed propellers and the original offset of the propellers. These propellers are selected as research objects to determine the hydrodynamic performance error between the propeller constructed by the proposed model and a benchmark propeller. According to the results of the numerical study, the parametric 3D geometry model can precisely reconstruct the aforementioned geometry within a valid error range. The hydrodynamic error analysis demonstrates that the geometric inaccuracy from the reconstructed model has less impact on the propeller performance. This indicates that the model described in this study is generalised and robust. Moreover, some uncommon propeller CAD models were generated in batches using the parametric 3D geometry model.","PeriodicalId":49681,"journal":{"name":"Polish Maritime Research","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135688194","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：