Pub Date : 2021-12-13DOI: 10.5750/ijme.v157ia1.944
M. D. Woodward, M. Landamore, G. Rees, N. Allen, A. De Graauw, A. Mejer, J. E. Hutchins, M. Irvine, S. Short, D. Trodden, M. Labrosse, R. Gargiulo
From the thrusters on smaller, but numerous, harbour support vessels through to the pod-drives on cruise ships and ocean going liners, azimuth control has rapidly established itself in the maritime industry. From the design of the ship, to the training of personnel and the development of operational procedures, the industry has risen to meet the demand. However, this rapid evolution has not allowed sufficient time for the propagation of knowledge throughout the different disciplines. On a day-to-day basis, maritime pilots must deal with such ships, coping as they do, with an as yet unstandardized environment. This paper presents the findings of an EU project (AZIPILOT) considering accidents and incidents and concerning the training and operational practice of ships equipped with Azimuth Control Devices (ACD’s).
{"title":"ON THE SAFE PILOTAGE OF SHIP’S WITH PROPULSION THAT CAN AZIMUTH FOR STEERING","authors":"M. D. Woodward, M. Landamore, G. Rees, N. Allen, A. De Graauw, A. Mejer, J. E. Hutchins, M. Irvine, S. Short, D. Trodden, M. Labrosse, R. Gargiulo","doi":"10.5750/ijme.v157ia1.944","DOIUrl":"https://doi.org/10.5750/ijme.v157ia1.944","url":null,"abstract":"From the thrusters on smaller, but numerous, harbour support vessels through to the pod-drives on cruise ships and ocean going liners, azimuth control has rapidly established itself in the maritime industry. From the design of the ship, to the training of personnel and the development of operational procedures, the industry has risen to meet the demand. However, this rapid evolution has not allowed sufficient time for the propagation of knowledge throughout the different disciplines. On a day-to-day basis, maritime pilots must deal with such ships, coping as they do, with an as yet unstandardized environment. This paper presents the findings of an EU project (AZIPILOT) considering accidents and incidents and concerning the training and operational practice of ships equipped with Azimuth Control Devices (ACD’s).","PeriodicalId":50313,"journal":{"name":"International Journal of Maritime Engineering","volume":" ","pages":""},"PeriodicalIF":0.4,"publicationDate":"2021-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41475680","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}
Pub Date : 2021-12-13DOI: 10.5750/ijme.v162ia1.1123
H. Chen, H. Ren, B. Yang, J. Chen
This brief is devoted to the predesigned motion trajectory-based finite time dynamic positioning (DP) control for a marine surface vehicle (MSV) with unknown external disturbances. Firstly, a preset motion trajectory is presented through establishing the relationship function among position tracking errors and heading tracking error, facilitating the MSV to arrive in the equilibrium point along the pre-designed trajectory. Furthermore, a novel nonsingular and fast terminal sliding mode control (NTSMC) approach is investigated, which ensures faster convergence rate and better stability performance of the close-loop system than the conventional backstepping control approach. What’s more, by incorporating the adaptive technique with the NTSMC approach, an adaptive nonsingular and fast terminal sliding mode control (ANTSMC) strategy is addressed. Compared to the NTSMC approach, it strengthens robustness to disturbances and guarantees system states to converge to a closer neighborhood of the equilibrium point. Finally, simulation results illustrate the remarkable effectiveness of proposed control schemes.
{"title":"THE MOTION TRAJECTORY-BASED FINITE-TIME CONTROL FOR THE MARINE SURFACE VEHICLE","authors":"H. Chen, H. Ren, B. Yang, J. Chen","doi":"10.5750/ijme.v162ia1.1123","DOIUrl":"https://doi.org/10.5750/ijme.v162ia1.1123","url":null,"abstract":"This brief is devoted to the predesigned motion trajectory-based finite time dynamic positioning (DP) control for a marine surface vehicle (MSV) with unknown external disturbances. Firstly, a preset motion trajectory is presented through establishing the relationship function among position tracking errors and heading tracking error, facilitating the MSV to arrive in the equilibrium point along the pre-designed trajectory. Furthermore, a novel nonsingular and fast terminal sliding mode control (NTSMC) approach is investigated, which ensures faster convergence rate and better stability performance of the close-loop system than the conventional backstepping control approach. What’s more, by incorporating the adaptive technique with the NTSMC approach, an adaptive nonsingular and fast terminal sliding mode control (ANTSMC) strategy is addressed. Compared to the NTSMC approach, it strengthens robustness to disturbances and guarantees system states to converge to a closer neighborhood of the equilibrium point. Finally, simulation results illustrate the remarkable effectiveness of proposed control schemes.","PeriodicalId":50313,"journal":{"name":"International Journal of Maritime Engineering","volume":" ","pages":""},"PeriodicalIF":0.4,"publicationDate":"2021-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43853262","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}
Pub Date : 2021-12-13DOI: 10.5750/ijme.v152ia4.837
K. Spyrou
The article intends to bring back to light old perceptions about the “broaching-to” behaviour of ships. The signature of broaching-to is the sudden loss of controllability. The phenomenon sometimes ends with vessel capsize. The findings of an investigation into old bibliographical sources are reported, spanning more than 300 years of use of the term. Several citations have been identified in texts of nautical or related content, including voyagers’ records, nautical journals, training manuals, old encyclopaedias and even literary sources and leisure magazines. At a time when broaching-to is considered in the currently formulated new ship stability criteria at IMO, this paper provides a historical perspective on a problem that has maintained relevance despite the changes in ship technology and design.
{"title":"HISTORICAL TRAILS OF SHIP BROACHING-TO","authors":"K. Spyrou","doi":"10.5750/ijme.v152ia4.837","DOIUrl":"https://doi.org/10.5750/ijme.v152ia4.837","url":null,"abstract":"The article intends to bring back to light old perceptions about the “broaching-to” behaviour of ships. The signature of broaching-to is the sudden loss of controllability. The phenomenon sometimes ends with vessel capsize. The findings of an investigation into old bibliographical sources are reported, spanning more than 300 years of use of the term. Several citations have been identified in texts of nautical or related content, including voyagers’ records, nautical journals, training manuals, old encyclopaedias and even literary sources and leisure magazines. At a time when broaching-to is considered in the currently formulated new ship stability criteria at IMO, this paper provides a historical perspective on a problem that has maintained relevance despite the changes in ship technology and design.","PeriodicalId":50313,"journal":{"name":"International Journal of Maritime Engineering","volume":" ","pages":""},"PeriodicalIF":0.4,"publicationDate":"2021-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46600494","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}
Pub Date : 2021-12-13DOI: 10.5750/ijme.v162ia1.1116
N. Johnson, G. Macfarlane, J. Duffy, I. Penesis, R. J. Ballantyne
An experimental campaign has been undertaken to explore the flow around a feeder vessel as it manoeuvres in and out of the well dock of a mothership. The parent hulls for this study are drawn from the floating harbour transhipper concept created by Sea Transport Corporation. Laser measurement techniques have been employed to analyse the flow field within the well dock while the feeder vessel both enters and departs. For the Master of the feeder vessel to safely perform these manoeuvres, the complex flows resulting from the highly confined nature of the well dock concept need to be understood and potentially mitigated. It is shown that the inclusion of vents in the well dock can significantly influence the flow and that their effectiveness is determined by the size of the vents. This study further progresses the authors’ recent work on the same novel concept where the confined water effect of the well dock and inclusion of vents is quantified for both the seakeeping behaviour and the docking/departure performance. It is concluded that the use of vents is very beneficial when a feeder vessel docks or departs the well dock, however a compromise on the vent size must be reached in order to reduce adverse effects on feeder vessel motions when docked and exposed to a seaway. It is likely that the optimum solution, that covers all operational parameters, only requires the inclusion of relatively small vents.
{"title":"INSIGHTS INTO THE FLOW WITHIN THE WELL DOCK OF A MOTHERSHIP DURING FEEDER VESSEL DOCKING MANOEUVRES","authors":"N. Johnson, G. Macfarlane, J. Duffy, I. Penesis, R. J. Ballantyne","doi":"10.5750/ijme.v162ia1.1116","DOIUrl":"https://doi.org/10.5750/ijme.v162ia1.1116","url":null,"abstract":"An experimental campaign has been undertaken to explore the flow around a feeder vessel as it manoeuvres in and out of the well dock of a mothership. The parent hulls for this study are drawn from the floating harbour transhipper concept created by Sea Transport Corporation. Laser measurement techniques have been employed to analyse the flow field within the well dock while the feeder vessel both enters and departs. For the Master of the feeder vessel to safely perform these manoeuvres, the complex flows resulting from the highly confined nature of the well dock concept need to be understood and potentially mitigated. It is shown that the inclusion of vents in the well dock can significantly influence the flow and that their effectiveness is determined by the size of the vents. This study further progresses the authors’ recent work on the same novel concept where the confined water effect of the well dock and inclusion of vents is quantified for both the seakeeping behaviour and the docking/departure performance. It is concluded that the use of vents is very beneficial when a feeder vessel docks or departs the well dock, however a compromise on the vent size must be reached in order to reduce adverse effects on feeder vessel motions when docked and exposed to a seaway. It is likely that the optimum solution, that covers all operational parameters, only requires the inclusion of relatively small vents.","PeriodicalId":50313,"journal":{"name":"International Journal of Maritime Engineering","volume":" ","pages":""},"PeriodicalIF":0.4,"publicationDate":"2021-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46624361","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 correct estimation of set-up is very important to evaluate coastal hazard and to design coastal structures. In this paper, we derived a mathematical expression for wave set-up in the context of random waves. The solution to this expression assumes straight, parallel depth contours and constant average flow parameters in the longshore direction. We then investigated the effect of different types of sea state taking account of different frequency spectrum and spreading function assumed in the expression on estimates of wave set-up. We found the set-up was highly influenced by the frequency spectrum used. Finally, we applied this expression to estimate set-up values at locations in Italy and in the United States using buoy data provided by ISPRA (Istituto Superiore per la Protezione e la Ricerca Ambientale) and NDBC (National Data Buoy Centre).
正确估计设置对于评估海岸灾害和设计海岸结构非常重要。在本文中，我们推导了随机波背景下波浪设置的数学表达式。该表达式的解决方案假定了直的、平行的深度等值线和沿沿岸方向的恒定平均流量参数。然后，考虑到表达式中假设的不同频谱和扩展函数，我们研究了不同类型海况对波浪设置估计的影响。我们发现这种设置受到所用频谱的高度影响。最后，我们使用ISPRA（Istituto Superiore per la Protezione e la Ricerca Ambientale）和NDBC（国家数据浮标中心）提供的浮标数据，将该表达式应用于估计意大利和美国各地的设置值。
{"title":"SET-UP DUE TO RANDOM WAVES: INFLUENCE OF THE DIRECTIONAL SPECTRUM","authors":"G. Barbaro, G. Foti, G. Malara","doi":"10.1115/OMAE2011-49977","DOIUrl":"https://doi.org/10.1115/OMAE2011-49977","url":null,"abstract":"\u0000 \u0000 \u0000The correct estimation of set-up is very important to evaluate coastal hazard and to design coastal structures. In this paper, we derived a mathematical expression for wave set-up in the context of random waves. The solution to this expression assumes straight, parallel depth contours and constant average flow parameters in the longshore direction. We then investigated the effect of different types of sea state taking account of different frequency spectrum and spreading function assumed in the expression on estimates of wave set-up. We found the set-up was highly influenced by the frequency spectrum used. Finally, we applied this expression to estimate set-up values at locations in Italy and in the United States using buoy data provided by ISPRA (Istituto Superiore per la Protezione e la Ricerca Ambientale) and NDBC (National Data Buoy Centre). \u0000 \u0000 \u0000","PeriodicalId":50313,"journal":{"name":"International Journal of Maritime Engineering","volume":" ","pages":""},"PeriodicalIF":0.4,"publicationDate":"2021-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1115/OMAE2011-49977","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47042147","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}
Pub Date : 2021-12-13DOI: 10.5750/ijme.v156ia2.922
V. Rumawas, B. Asbjørnslett
Most serious accidents at sea are caused by minor incidents that escalated into an uncontrolled situation. This study is aiming to develop a model to investigate the likelihood of fatal accidents, given that a critical incident has already occurred. The focus of the study is on human behaviour, adopting a hardware reliability perspective. The vessel is considered as a safety-critical system to be protected by several barriers. The crew role is modelled as active barriers and distinguishing between different functions: perception, decision and action. A Markov approach is proposed to model different situations on the vessel. A mathematical model to estimate the probability of failure in an emergency situation is formulated. A new parameter is defined for the survivability of a vessel, given that a critical incident has taken place. The methods were applied to examine ship-platform collisions cases and the results show strong benefits for diagnosing and evaluating accidents from a human factors perspective as well as for training purposes.
{"title":"SURVIVABILITY OF SHIPS AT SEA: A PROPOSED MODEL TO ACCOUNT FOR HUMAN FACTORS IN A SAFETY-CRITICAL SYSTEM","authors":"V. Rumawas, B. Asbjørnslett","doi":"10.5750/ijme.v156ia2.922","DOIUrl":"https://doi.org/10.5750/ijme.v156ia2.922","url":null,"abstract":"Most serious accidents at sea are caused by minor incidents that escalated into an uncontrolled situation. This study is aiming to develop a model to investigate the likelihood of fatal accidents, given that a critical incident has already occurred. The focus of the study is on human behaviour, adopting a hardware reliability perspective. The vessel is considered as a safety-critical system to be protected by several barriers. The crew role is modelled as active barriers and distinguishing between different functions: perception, decision and action. A Markov approach is proposed to model different situations on the vessel. A mathematical model to estimate the probability of failure in an emergency situation is formulated. A new parameter is defined for the survivability of a vessel, given that a critical incident has taken place. The methods were applied to examine ship-platform collisions cases and the results show strong benefits for diagnosing and evaluating accidents from a human factors perspective as well as for training purposes.","PeriodicalId":50313,"journal":{"name":"International Journal of Maritime Engineering","volume":" ","pages":""},"PeriodicalIF":0.4,"publicationDate":"2021-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47110605","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}
Pub Date : 2021-12-13DOI: 10.5750/ijme.v156ia4.938
Shan Wang, H. Luo, C. Guedes Soares
The two-dimensional water entry of bow-flared sections is studied by using a Multi-Material Arbitrary Lagrangian- Eulerian (MMALE) formulation and a penalty-coupling algorithm. A convergence study is carried out, considering the effects of mesh size, the dimension of fluids domain, and fluid leakage phenomenon through the structure. The predicted results on the wetted surface of a bow-flared section are compared with published experimental values in terms of vertical slamming force, pressure distributions at different time instances and the pressure histories at different points. Comparisons between the numerical results and measured values show satisfactory correlation. An approximation method is adopted to estimate the sectional slamming force showing good consistency for the peak forces.
{"title":"NUMERICAL PREDICTION OF SLAMMING LOADS DURING WATER ENTRY OF BOW-FLARED SECTIONS","authors":"Shan Wang, H. Luo, C. Guedes Soares","doi":"10.5750/ijme.v156ia4.938","DOIUrl":"https://doi.org/10.5750/ijme.v156ia4.938","url":null,"abstract":"The two-dimensional water entry of bow-flared sections is studied by using a Multi-Material Arbitrary Lagrangian- Eulerian (MMALE) formulation and a penalty-coupling algorithm. A convergence study is carried out, considering the effects of mesh size, the dimension of fluids domain, and fluid leakage phenomenon through the structure. The predicted results on the wetted surface of a bow-flared section are compared with published experimental values in terms of vertical slamming force, pressure distributions at different time instances and the pressure histories at different points. Comparisons between the numerical results and measured values show satisfactory correlation. An approximation method is adopted to estimate the sectional slamming force showing good consistency for the peak forces.","PeriodicalId":50313,"journal":{"name":"International Journal of Maritime Engineering","volume":" ","pages":""},"PeriodicalIF":0.4,"publicationDate":"2021-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48508349","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}
Pub Date : 2021-12-13DOI: 10.5750/ijme.v155ia4.910
S. Petinov, R. Guchinsky
Despite the long history of application of subdivided superstructures and deckhouses, and efforts of ship designers and researchers a sensible solution in design of reliable details at the cut endings was not found yet. It may be explained as consequence of controversial requirements in design of the cut endings. Fatigue design of the superstructure details is addressed to solution of the problem. Presented is an example of fatigue design of the cut ending in a fast ship superstructure based on application of modified «Strain-Life» criterion for fatigue and subsequent approach which utilizes Neuber’s formula and material cyclic properties. To realize the approach a procedure of the long-term stress distribution transformation to the block-type format is developed. Efficiency of the developed technique is illustrated by comparing the results with those of application standard S-N criteria based techniques. The results of analysis allowed selection of the expansion joint detail of the superstructure geometry and construction procedure providing necessary reliability.
{"title":"FATIGUE ASSESSMENT OF SHIP SUPERSTRUCTURE AT EXPANSION JOINT","authors":"S. Petinov, R. Guchinsky","doi":"10.5750/ijme.v155ia4.910","DOIUrl":"https://doi.org/10.5750/ijme.v155ia4.910","url":null,"abstract":"Despite the long history of application of subdivided superstructures and deckhouses, and efforts of ship designers and researchers a sensible solution in design of reliable details at the cut endings was not found yet. It may be explained as consequence of controversial requirements in design of the cut endings. \u0000Fatigue design of the superstructure details is addressed to solution of the problem. Presented is an example of fatigue design of the cut ending in a fast ship superstructure based on application of modified «Strain-Life» criterion for fatigue and subsequent approach which utilizes Neuber’s formula and material cyclic properties. To realize the approach a procedure of the long-term stress distribution transformation to the block-type format is developed. Efficiency of the developed technique is illustrated by comparing the results with those of application standard S-N criteria based techniques. The results of analysis allowed selection of the expansion joint detail of the superstructure geometry and construction procedure providing necessary reliability.","PeriodicalId":50313,"journal":{"name":"International Journal of Maritime Engineering","volume":" ","pages":""},"PeriodicalIF":0.4,"publicationDate":"2021-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46115488","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}
Pub Date : 2021-12-13DOI: 10.3940/rina.ijme.2015.a1.303
T. Arnold, J. Lavroff, Davis
Trim tabs form an important part of motion control systems on high-speed watercraft. By altering the pitch angle, significant improvements in propulsion efficiency can be achieved by reducing overall resistance. For a ship in heavy seas, trim tabs can also be used to reduce structural loads by changing the vessel orientation in response to encountered waves. In this study, trials have been conducted in the University of Tasmania hydraulics laboratory using a closed- circuit water tunnel to measure model scale trim tab forces. The model scale system replicates the stern tabs on the full- scale INCAT Tasmania 112 m high-speed wave-piercer catamaran. The model was designed for total lift force measurement and pressure tappings allowed for pressures to be measured at fixed locations on the underside of the hull and tab. This investigation examines the pressures at various flow velocities and tab deflection angles for the case of horizontal vessel trim. A simplified two-dimensional CFD model of the hull and tab has also been analysed using ANSYS CFX software. The results of model tests and CFD indicate that the maximum pressure occurs in the vicinity of the tab hinge and that the pressure distribution is long-tailed in the direction forward of the hinge. This accounts for the location of the resultant lift force, which is found to act forward of the tab hinge.
{"title":"PRESSURE DISTRIBUTION DUE TO STERN TAB DEFLECTION AT MODEL SCALE","authors":"T. Arnold, J. Lavroff, Davis","doi":"10.3940/rina.ijme.2015.a1.303","DOIUrl":"https://doi.org/10.3940/rina.ijme.2015.a1.303","url":null,"abstract":"Trim tabs form an important part of motion control systems on high-speed watercraft. By altering the pitch angle, significant improvements in propulsion efficiency can be achieved by reducing overall resistance. For a ship in heavy seas, trim tabs can also be used to reduce structural loads by changing the vessel orientation in response to encountered waves. In this study, trials have been conducted in the University of Tasmania hydraulics laboratory using a closed- circuit water tunnel to measure model scale trim tab forces. The model scale system replicates the stern tabs on the full- scale INCAT Tasmania 112 m high-speed wave-piercer catamaran. The model was designed for total lift force measurement and pressure tappings allowed for pressures to be measured at fixed locations on the underside of the hull and tab. This investigation examines the pressures at various flow velocities and tab deflection angles for the case of horizontal vessel trim. A simplified two-dimensional CFD model of the hull and tab has also been analysed using ANSYS CFX software. The results of model tests and CFD indicate that the maximum pressure occurs in the vicinity of the tab hinge and that the pressure distribution is long-tailed in the direction forward of the hinge. This accounts for the location of the resultant lift force, which is found to act forward of the tab hinge.","PeriodicalId":50313,"journal":{"name":"International Journal of Maritime Engineering","volume":" ","pages":""},"PeriodicalIF":0.4,"publicationDate":"2021-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44829456","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}
Pub Date : 2021-12-13DOI: 10.5750/ijme.v154ia2.877
R. Leaper, M. Renilson
Underwater noise pollution from shipping is of considerable concern for marine life, particularly due to the potential for raised ambient noise levels in the 10-300Hz frequency range to mask biological sounds. There is widespread agreement that reducing shipping noise is both necessary and feasible, and the International Maritime Organization is actively working on the issue. The main source of noise is associated with propeller cavitation, and measures to improve propeller design and wake flow may also reduce noise. It is likely that the noisiest 10% of ships generate the majority of the noise impact, and it may be possible to quieten these vessels through measures that also improve efficiency. However, an extensive data set of full scale noise measurements of ships under operating conditions is required to fully understand how different factors relate to noise output and how noise reduction can be achieved alongside energy saving measures.
{"title":"A REVIEW OF PRACTICAL METHODS FOR REDUCING UNDERWATER NOISE POLLUTION FROM LARGE COMMERCIAL VESSELS","authors":"R. Leaper, M. Renilson","doi":"10.5750/ijme.v154ia2.877","DOIUrl":"https://doi.org/10.5750/ijme.v154ia2.877","url":null,"abstract":"Underwater noise pollution from shipping is of considerable concern for marine life, particularly due to the potential for raised ambient noise levels in the 10-300Hz frequency range to mask biological sounds. There is widespread agreement that reducing shipping noise is both necessary and feasible, and the International Maritime Organization is actively working on the issue. The main source of noise is associated with propeller cavitation, and measures to improve propeller design and wake flow may also reduce noise. It is likely that the noisiest 10% of ships generate the majority of the noise impact, and it may be possible to quieten these vessels through measures that also improve efficiency. However, an extensive data set of full scale noise measurements of ships under operating conditions is required to fully understand how different factors relate to noise output and how noise reduction can be achieved alongside energy saving measures.","PeriodicalId":50313,"journal":{"name":"International Journal of Maritime Engineering","volume":" ","pages":""},"PeriodicalIF":0.4,"publicationDate":"2021-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47458558","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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