Shipborne cranes are widely used in marine engineering and are employed in more diversified working scenes. However, due to the extensive swing range of ships, it is impossible to locate the payload accurately. A constant tension control method of payload anti-swing is proposed based on the principle of linear velocity feedback. This paper establishes a dynamic model of the payload anti-swing system driven by hydraulic motors. The characteristics of the payload swing and the cable tension are obtained through the dynamic simulation. The simulation and experimental results show that the constant tension control method significantly suppresses the shipborne crane’s payload swing, and the payload anti-swing effect reaches 73% and 85.6%. It is also found that the payload swings asymmetrically under external excitation. In addition, the effects of payload asymmetric swing on cable tension, payload swing angle, and the hydraulic pump output oil pressure are studied by a payload asymmetric swing experiment, and the results show that the proposed method also has a good suppression effect on the asymmetric payload swing.
{"title":"Dynamic modeling and control of hydraulic driven payload anti-swing system for shipborne cranes","authors":"G. Jin, Yu-qing Sun, Hongyu Cheng, Hailong Sun, Shenghai Wang, Haiquan Chen","doi":"10.1177/14750902231170914","DOIUrl":"https://doi.org/10.1177/14750902231170914","url":null,"abstract":"Shipborne cranes are widely used in marine engineering and are employed in more diversified working scenes. However, due to the extensive swing range of ships, it is impossible to locate the payload accurately. A constant tension control method of payload anti-swing is proposed based on the principle of linear velocity feedback. This paper establishes a dynamic model of the payload anti-swing system driven by hydraulic motors. The characteristics of the payload swing and the cable tension are obtained through the dynamic simulation. The simulation and experimental results show that the constant tension control method significantly suppresses the shipborne crane’s payload swing, and the payload anti-swing effect reaches 73% and 85.6%. It is also found that the payload swings asymmetrically under external excitation. In addition, the effects of payload asymmetric swing on cable tension, payload swing angle, and the hydraulic pump output oil pressure are studied by a payload asymmetric swing experiment, and the results show that the proposed method also has a good suppression effect on the asymmetric payload swing.","PeriodicalId":20667,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87892700","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 : 2023-04-19DOI: 10.1177/14750902231168674
Yijun Sun, A. Hamada, O. Sallam, B. Windén, M. Fürth
Numerical Wave Tanks (NWTs) allow for in-depth investigations into the hydrodynamics and wave responses of floating objects. Thus, they are widely used during the design phase of many offshore platforms and devices. Such problems often feature low turbulence, with wave propagation and wave-object interaction being the key features. In this paper, the merits of using a laminar flow model for a NWT with a free-to-heave buoy, subject to second order Stokes waves in a low sea state is investigated. The simulations are implemented using the interFoam solver, which is embedded in OpenFOAM. The time series of waves measured upstream and downstream of the buoy, and the buoy hydrodynamics are compared to analytical and experimental results for accuracy evaluations. It is shown that, due to the low turbulence level of the problem, the laminar approach can deliver more accurate results than turbulent models, such as Reynolds-averaged Navier-Stokes Simulation (RANS) or partially-averaged Navier-Stokes Simulation (PANS). Moreover, the simulation time of the laminar simulations is significantly shorter than to those of RANS and PANS.
{"title":"The application of laminar numerical wave tank for a heaving buoy hydrodynamics study in low-turbulence nonlinear waves","authors":"Yijun Sun, A. Hamada, O. Sallam, B. Windén, M. Fürth","doi":"10.1177/14750902231168674","DOIUrl":"https://doi.org/10.1177/14750902231168674","url":null,"abstract":"Numerical Wave Tanks (NWTs) allow for in-depth investigations into the hydrodynamics and wave responses of floating objects. Thus, they are widely used during the design phase of many offshore platforms and devices. Such problems often feature low turbulence, with wave propagation and wave-object interaction being the key features. In this paper, the merits of using a laminar flow model for a NWT with a free-to-heave buoy, subject to second order Stokes waves in a low sea state is investigated. The simulations are implemented using the interFoam solver, which is embedded in OpenFOAM. The time series of waves measured upstream and downstream of the buoy, and the buoy hydrodynamics are compared to analytical and experimental results for accuracy evaluations. It is shown that, due to the low turbulence level of the problem, the laminar approach can deliver more accurate results than turbulent models, such as Reynolds-averaged Navier-Stokes Simulation (RANS) or partially-averaged Navier-Stokes Simulation (PANS). Moreover, the simulation time of the laminar simulations is significantly shorter than to those of RANS and PANS.","PeriodicalId":20667,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86010400","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 : 2023-04-17DOI: 10.1177/14750902231165808
D. Sengupta, Tushar Kanti Show, S. Hirdaris, R. Datta
This paper presents a semi analytic time domain method for the analysis of the symmetric hydroelastic response of a container ship subject to slamming and green water loads. An Impulse Response Function (IRF) is adopted for the calculation of radiation, diffraction and wave excitation forces. Local hydrodynamic forces associated with green water on decks and slamming loads are respectively modelled by the Buchner’s Dam Break Model and a Generalised Wagner Model. The structural responses are captured by Euler-Bernoulli beam theory and solved by the modal superposition method. The Duhamel Integral technique is used to evaluate the dynamic response. A parametric study demonstrates how external forces may affect the global wave induced vertical bending moments and shear forces. Numerical simulations are compared against a hybrid method that combines computational fluid dynamics, boundary element and finite element methods for low to medium frequency induced dynamic response. It is concluded that the proposed semi analytic methodology is fast and accurate and may be useful at concept ship design stage.
{"title":"A semi analytic method for the analysis of the symmetric hydroelastic response of a container ship under slamming and green water loads","authors":"D. Sengupta, Tushar Kanti Show, S. Hirdaris, R. Datta","doi":"10.1177/14750902231165808","DOIUrl":"https://doi.org/10.1177/14750902231165808","url":null,"abstract":"This paper presents a semi analytic time domain method for the analysis of the symmetric hydroelastic response of a container ship subject to slamming and green water loads. An Impulse Response Function (IRF) is adopted for the calculation of radiation, diffraction and wave excitation forces. Local hydrodynamic forces associated with green water on decks and slamming loads are respectively modelled by the Buchner’s Dam Break Model and a Generalised Wagner Model. The structural responses are captured by Euler-Bernoulli beam theory and solved by the modal superposition method. The Duhamel Integral technique is used to evaluate the dynamic response. A parametric study demonstrates how external forces may affect the global wave induced vertical bending moments and shear forces. Numerical simulations are compared against a hybrid method that combines computational fluid dynamics, boundary element and finite element methods for low to medium frequency induced dynamic response. It is concluded that the proposed semi analytic methodology is fast and accurate and may be useful at concept ship design stage.","PeriodicalId":20667,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73989148","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 : 2023-04-14DOI: 10.1177/14750902231167073
Ziwen Yu, Xinjiang Wei, Huifeng Zhang, Xin Hu, Jian Han
Anti-disturbance control problem is studied for ship dynamic positioning systems with model uncertainties and ocean disturbances under thruster faults. For the ocean disturbance, a stochastic disturbance observer (SDO) is established to give the online estimation. For thruster faults, an adaptive law is used to evaluate, which is obtain from Lyapunov function. For model uncertainties, a robust control term with adaptive technology is used to attenuate it. Then, a composite anti-disturbance control (CADC) strategy is raised by combining disturbance observer-based control (DOBC), adaptive technology, and robust control term, which makes the position and yaw angle of ship reach the desired values. Finally, the simulation example proves the validity of the controller.
{"title":"Composite anti-disturbance control for ship dynamic positioning systems with thruster faults","authors":"Ziwen Yu, Xinjiang Wei, Huifeng Zhang, Xin Hu, Jian Han","doi":"10.1177/14750902231167073","DOIUrl":"https://doi.org/10.1177/14750902231167073","url":null,"abstract":"Anti-disturbance control problem is studied for ship dynamic positioning systems with model uncertainties and ocean disturbances under thruster faults. For the ocean disturbance, a stochastic disturbance observer (SDO) is established to give the online estimation. For thruster faults, an adaptive law is used to evaluate, which is obtain from Lyapunov function. For model uncertainties, a robust control term with adaptive technology is used to attenuate it. Then, a composite anti-disturbance control (CADC) strategy is raised by combining disturbance observer-based control (DOBC), adaptive technology, and robust control term, which makes the position and yaw angle of ship reach the desired values. Finally, the simulation example proves the validity of the controller.","PeriodicalId":20667,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135076534","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 : 2023-04-13DOI: 10.1177/14750902231166424
O. Sallam, M. Fürth
Physics Informed Neural Networks (PINN), a deep learning tool, has recently become an effective method for solving inverse Partial Differential Equations (PDEs) where the boundary/initial conditions are not well defined and only noisy sparse measurements sampled in the domain exist. PINN, and other Neural Networks, tends to converge to the low frequency solution in a field that has multiple frequency scales, this is known as spectral bias. For PINN this happens when solving PDEs that exhibit periodic behavior spatially and temporally with multi frequency scales. Previous studies suggested that Fourier Features-Neural Networks (FF-NN) can be used to overcome the spectral bias problem. They proposed the Multi Scale-Spatio Temporal-Fourier Features-Physics Informed Neural Networks (MS-ST-FF-PINN) to overcome the spectral bias problem in PDEs solved by PINN. This has been evaluated on basic PDEs such as Poisson, wave and Gray-Scott equations. In this paper we take MS-ST-FF-PINN a step further by applying it to the incompressible Navier-Stokes equations. Furthermore, a comparative analysis between the PINN and the MS-ST-FF-PINN architectures solution accuracy, the learnt frequency components and the rate of convergence to the correct solution is included. To show this three test cases are shown (a)-Forward time independent double-lid-driven cavity, (b)-Inverse time independent free surface estimation of Kelvin wave pattern, and (c)-Inverse 2D time-dependent turbulent Von Karman vortex shedding interaction downstream of multiple cylinders. The results show that MS-ST-FF-PINN is better at learning low and high frequency components synchronously at early training iterations compared to the PINN architecture that does not learn the high frequency components even after multiple iteration numbers such as the Kelvin wave pattern and the Karman vortex shedding cases. However, for the third test case, the MS-ST-FF-PINN architecture showed a discontinuity for the temporal prediction of the pressure field due to over-fitting.
{"title":"On the use of Fourier Features-Physics Informed Neural Networks (FF-PINN) for forward and inverse fluid mechanics problems","authors":"O. Sallam, M. Fürth","doi":"10.1177/14750902231166424","DOIUrl":"https://doi.org/10.1177/14750902231166424","url":null,"abstract":"Physics Informed Neural Networks (PINN), a deep learning tool, has recently become an effective method for solving inverse Partial Differential Equations (PDEs) where the boundary/initial conditions are not well defined and only noisy sparse measurements sampled in the domain exist. PINN, and other Neural Networks, tends to converge to the low frequency solution in a field that has multiple frequency scales, this is known as spectral bias. For PINN this happens when solving PDEs that exhibit periodic behavior spatially and temporally with multi frequency scales. Previous studies suggested that Fourier Features-Neural Networks (FF-NN) can be used to overcome the spectral bias problem. They proposed the Multi Scale-Spatio Temporal-Fourier Features-Physics Informed Neural Networks (MS-ST-FF-PINN) to overcome the spectral bias problem in PDEs solved by PINN. This has been evaluated on basic PDEs such as Poisson, wave and Gray-Scott equations. In this paper we take MS-ST-FF-PINN a step further by applying it to the incompressible Navier-Stokes equations. Furthermore, a comparative analysis between the PINN and the MS-ST-FF-PINN architectures solution accuracy, the learnt frequency components and the rate of convergence to the correct solution is included. To show this three test cases are shown (a)-Forward time independent double-lid-driven cavity, (b)-Inverse time independent free surface estimation of Kelvin wave pattern, and (c)-Inverse 2D time-dependent turbulent Von Karman vortex shedding interaction downstream of multiple cylinders. The results show that MS-ST-FF-PINN is better at learning low and high frequency components synchronously at early training iterations compared to the PINN architecture that does not learn the high frequency components even after multiple iteration numbers such as the Kelvin wave pattern and the Karman vortex shedding cases. However, for the third test case, the MS-ST-FF-PINN architecture showed a discontinuity for the temporal prediction of the pressure field due to over-fitting.","PeriodicalId":20667,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74365387","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 : 2023-04-13DOI: 10.1177/14750902231166442
Kang-Ki Lee, Wilfried Hochegger, A. Schönborn
This study reports the energy specific air emissions from a diesel-cycle high pressure injection dual fuel engine for operation on liquefied natural gas and heavy fuel oil. An experiment at sea was performed onboard a bulk carrier during commercial voyages, to measure the efficiency of the engine and to measure air emissions relevant to air pollution and climate impact for operation on both fuels. The measurements showed that the energy conversion efficiency of the engine was higher for operation on liquefied natural gas because its lower NOx emissions permitted the use of a higher effective compression ratio whilst meeting the same NOx emissions level. The results showed that the climate impact for operation on heavy fuel oil was 2.1–2.3 times higher than for liquefied natural gas at 50% load, if considering only the emissions occurring at the engine. Analysis of the air emissions for their individual contributions to climate impacts suggested that black carbon had the strongest climate impact of all air emissions in the case of operation on heavy fuel oil. For operation on liquefied natural gas, CO2 had the strongest individual climate impact amongst the air emissions from the engine.
{"title":"Energy-specific greenhouse gas emissions measurements from 2-stroke marine diesel engine using liquefied natural gas","authors":"Kang-Ki Lee, Wilfried Hochegger, A. Schönborn","doi":"10.1177/14750902231166442","DOIUrl":"https://doi.org/10.1177/14750902231166442","url":null,"abstract":"This study reports the energy specific air emissions from a diesel-cycle high pressure injection dual fuel engine for operation on liquefied natural gas and heavy fuel oil. An experiment at sea was performed onboard a bulk carrier during commercial voyages, to measure the efficiency of the engine and to measure air emissions relevant to air pollution and climate impact for operation on both fuels. The measurements showed that the energy conversion efficiency of the engine was higher for operation on liquefied natural gas because its lower NOx emissions permitted the use of a higher effective compression ratio whilst meeting the same NOx emissions level. The results showed that the climate impact for operation on heavy fuel oil was 2.1–2.3 times higher than for liquefied natural gas at 50% load, if considering only the emissions occurring at the engine. Analysis of the air emissions for their individual contributions to climate impacts suggested that black carbon had the strongest climate impact of all air emissions in the case of operation on heavy fuel oil. For operation on liquefied natural gas, CO2 had the strongest individual climate impact amongst the air emissions from the engine.","PeriodicalId":20667,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89174875","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 : 2023-04-13DOI: 10.1177/14750902231166958
Christine M. Gilbert, M. Javaherian, C. Woolsey, Mark L. Shepheard
Virginia Tech has recently acquired a new towing carriage and vertical planar motion mechanism. The new towing carriage replaces the original carriage that was installed in the 1960s. The original carriage had a maximum speed of roughly 3 m/s, and the new carriage has a maximum speed of 7 m/s with the current wavemaker installation. The towing tank facility is used for both teaching and research activities in ocean engineering. The vertical planar motion mechanism includes two linear actuators to change the pitching and heaving behavior of a surface or subsurface test article to model different phenomena such as slamming or porpoising of surface vessels and vertical plane maneuvers for subsurface vessels. The focus of this paper is on the determination of the specifications for the towing tank to meet both teaching and research needs and the early resistance experiments that have been conducted during initial shake-down of the new facility. The authors will discuss how preliminary resistance experiments compare to the USNA towing tank facility.
{"title":"Virginia tech advanced towing carriage","authors":"Christine M. Gilbert, M. Javaherian, C. Woolsey, Mark L. Shepheard","doi":"10.1177/14750902231166958","DOIUrl":"https://doi.org/10.1177/14750902231166958","url":null,"abstract":"Virginia Tech has recently acquired a new towing carriage and vertical planar motion mechanism. The new towing carriage replaces the original carriage that was installed in the 1960s. The original carriage had a maximum speed of roughly 3 m/s, and the new carriage has a maximum speed of 7 m/s with the current wavemaker installation. The towing tank facility is used for both teaching and research activities in ocean engineering. The vertical planar motion mechanism includes two linear actuators to change the pitching and heaving behavior of a surface or subsurface test article to model different phenomena such as slamming or porpoising of surface vessels and vertical plane maneuvers for subsurface vessels. The focus of this paper is on the determination of the specifications for the towing tank to meet both teaching and research needs and the early resistance experiments that have been conducted during initial shake-down of the new facility. The authors will discuss how preliminary resistance experiments compare to the USNA towing tank facility.","PeriodicalId":20667,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80294602","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 : 2023-04-06DOI: 10.1177/14750902231166429
Sungeun Choi, Kiwon Kim, Hoyong Kim, Jeonghwa Seo, Kyung-Kyu Yang, S. Rhee
The present study concerns assessing and comparing the operability of two surface combatants with conventional and modern wave-piercing hulls. The operability is measured in terms of the percent-time-operable (PTO), based on the capability of missions in the annual operating condition by seakeeping analysis. The seakeeping criteria of the surface combatant in various missions are selected by the literature review applicable to the basic design stage. The numerical seakeeping analysis is performed to obtain ship motion spectra in seaways around the Korean peninsula and North Pacific, after corrected by comparison to the experiments in regular waves. It is found that the wave-piercing hull has higher PTO than the flared hull under a generic operation scenario owing to reduced pitch motion and low resonance frequency of roll motion, the main restraint of seakeeping performance in PTO assessment.
{"title":"Assessment of percent-time-operable of surface combatants with conventional and wave-piercing hulls","authors":"Sungeun Choi, Kiwon Kim, Hoyong Kim, Jeonghwa Seo, Kyung-Kyu Yang, S. Rhee","doi":"10.1177/14750902231166429","DOIUrl":"https://doi.org/10.1177/14750902231166429","url":null,"abstract":"The present study concerns assessing and comparing the operability of two surface combatants with conventional and modern wave-piercing hulls. The operability is measured in terms of the percent-time-operable (PTO), based on the capability of missions in the annual operating condition by seakeeping analysis. The seakeeping criteria of the surface combatant in various missions are selected by the literature review applicable to the basic design stage. The numerical seakeeping analysis is performed to obtain ship motion spectra in seaways around the Korean peninsula and North Pacific, after corrected by comparison to the experiments in regular waves. It is found that the wave-piercing hull has higher PTO than the flared hull under a generic operation scenario owing to reduced pitch motion and low resonance frequency of roll motion, the main restraint of seakeeping performance in PTO assessment.","PeriodicalId":20667,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75709745","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}
To comply with the International Maritime Organization’s sulfur regulations, shipping companies have mainly favored scrubber systems. Even though the ship’s operations might be continued provided regulatory constraints are followed, the installation presents system-based risks depending on the scrubber type. This study’s primary aim is to inform the shipping industry about the risks associated with various scrubber applications on ships and to propose guidelines to ensure safer scrubber operation on marine vessels. Consequently, a risk evaluation is conducted on all kinds of scrubber systems. Experts in the marine industry identify the main subsystems and components and evaluate their failure modes and consequences. Using the fuzzy failure modes and effects analysis method, the acquired judgments are analyzed. The risk value of each failure scenario is computed using the Mamdani fuzzy inference technique and the evaluation of expert ratings. The riskiest failure modes identified by the investigation include the sensing element, injection nozzles, packed peds, and seawater system valves.
{"title":"A risk assessment of scrubber use for marine transport by rule-based fuzzy FMEA","authors":"Çağlar Karatuğ, Bulut Ozan Ceylan, Yasin Arslanoğlu","doi":"10.1177/14750902231166030","DOIUrl":"https://doi.org/10.1177/14750902231166030","url":null,"abstract":"To comply with the International Maritime Organization’s sulfur regulations, shipping companies have mainly favored scrubber systems. Even though the ship’s operations might be continued provided regulatory constraints are followed, the installation presents system-based risks depending on the scrubber type. This study’s primary aim is to inform the shipping industry about the risks associated with various scrubber applications on ships and to propose guidelines to ensure safer scrubber operation on marine vessels. Consequently, a risk evaluation is conducted on all kinds of scrubber systems. Experts in the marine industry identify the main subsystems and components and evaluate their failure modes and consequences. Using the fuzzy failure modes and effects analysis method, the acquired judgments are analyzed. The risk value of each failure scenario is computed using the Mamdani fuzzy inference technique and the evaluation of expert ratings. The riskiest failure modes identified by the investigation include the sensing element, injection nozzles, packed peds, and seawater system valves.","PeriodicalId":20667,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75049225","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 : 2023-03-29DOI: 10.1177/14750902231164789
Kun Zhou, Zhi-Feng Zhu, Bing Wang, Fang Zhou
The radiation noise generated by cavitation has been extensively studied for underwater target recognition, but there are few reports on the related mechanism of the cavitation noise of ship propellers that attract attention in the field of hydroacoustics. In this paper, the RANS equations of the underwater propeller wake field are constructed, and numerically solved by combining the cavitation model and the turbulence model. The power spectrum is used to analyze the signal of the numerical calculation results of the propeller wake pressure. The feature estimation and extraction are carried out to obtain the characteristic values of the specific characteristic parameters. These eigenvalues not only reflect the flow field characteristics but also the geometric parameters and working conditions of the propeller. Therefore, two models are established around the relationship between them. Firstly, these eigenvalues are used for regression analysis in multivariate statistics to obtain a statistical model reflecting the characteristics of propeller cavitation wake. Secondly, the relationship between the propeller skew angle and the low frequency linear spectrum amplitude is obtained by using the power spectrum diagram. In this paper, the processing results of the experimental data of the cavitation water tunnel with controllable parameters and the radiation noise data of the actual target are used to verify and supplement each other with the processing results of the feature model.
{"title":"Research on propeller cavitation wake characteristics based on multivariate statistical modeling method","authors":"Kun Zhou, Zhi-Feng Zhu, Bing Wang, Fang Zhou","doi":"10.1177/14750902231164789","DOIUrl":"https://doi.org/10.1177/14750902231164789","url":null,"abstract":"The radiation noise generated by cavitation has been extensively studied for underwater target recognition, but there are few reports on the related mechanism of the cavitation noise of ship propellers that attract attention in the field of hydroacoustics. In this paper, the RANS equations of the underwater propeller wake field are constructed, and numerically solved by combining the cavitation model and the turbulence model. The power spectrum is used to analyze the signal of the numerical calculation results of the propeller wake pressure. The feature estimation and extraction are carried out to obtain the characteristic values of the specific characteristic parameters. These eigenvalues not only reflect the flow field characteristics but also the geometric parameters and working conditions of the propeller. Therefore, two models are established around the relationship between them. Firstly, these eigenvalues are used for regression analysis in multivariate statistics to obtain a statistical model reflecting the characteristics of propeller cavitation wake. Secondly, the relationship between the propeller skew angle and the low frequency linear spectrum amplitude is obtained by using the power spectrum diagram. In this paper, the processing results of the experimental data of the cavitation water tunnel with controllable parameters and the radiation noise data of the actual target are used to verify and supplement each other with the processing results of the feature model.","PeriodicalId":20667,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87127134","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}
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：