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":"4 1","pages":"867 - 877"},"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":"40 1","pages":"818 - 830"},"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":"244 1","pages":""},"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":"1 1","pages":""},"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}
Pub Date : 2023-03-28DOI: 10.1177/14750902231163905
Lin Zhandong, Ma Shuang, Tao Jianguo, L. Jingkui, Wang Wei, W. Lina
To control precisely and investigate maneuverability of an underwater vehicle in a nuclear power pool this article presents a study on the mathematical model and the thrust characteristics of a ducted propeller under the quasi-cavitation effect by a numerical method. Firstly, a mathematical model of a ducted propeller including the quasi-cavitation effect term which is often ignored, is established based on the thrust performance under different quasi-cavitation distances and the revolution speed by CFD. Then the pressure field near the suction and pressure surface of blades are analyzed, which reveals that the thrust increases with a decrease of the quasi-cavitation distance. Finally, the thrust performances under different conditions are experimentally measured in an open-water pool, which can verify the reliability of the mathematical model below the error of 10%. The results demonstrates that the presented method can be used to evaluate the dynamic mechanism of a propeller, and hold a potential to improve the control strategy.
{"title":"Numerical and experimental investigation of the quasi-cavitation effect on a ducted Propeller for ROV","authors":"Lin Zhandong, Ma Shuang, Tao Jianguo, L. Jingkui, Wang Wei, W. Lina","doi":"10.1177/14750902231163905","DOIUrl":"https://doi.org/10.1177/14750902231163905","url":null,"abstract":"To control precisely and investigate maneuverability of an underwater vehicle in a nuclear power pool this article presents a study on the mathematical model and the thrust characteristics of a ducted propeller under the quasi-cavitation effect by a numerical method. Firstly, a mathematical model of a ducted propeller including the quasi-cavitation effect term which is often ignored, is established based on the thrust performance under different quasi-cavitation distances and the revolution speed by CFD. Then the pressure field near the suction and pressure surface of blades are analyzed, which reveals that the thrust increases with a decrease of the quasi-cavitation distance. Finally, the thrust performances under different conditions are experimentally measured in an open-water pool, which can verify the reliability of the mathematical model below the error of 10%. The results demonstrates that the presented method can be used to evaluate the dynamic mechanism of a propeller, and hold a potential to improve the control strategy.","PeriodicalId":20667,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment","volume":"16 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73958925","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 : 2023-03-22DOI: 10.1177/14750902231161120
Koushik Kanti Barman, S. Bora
This article studies the impact of a submerged interface-piercing perforated barrier in a two-layer fluid flowing over a permeable bottom. We investigate oblique wave scattering, trapping and radiation due to the structure focusing on the bottom permeability. The dead water phenomenon is analysed with the consideration of the bottom permeability, which results in a higher variation of the interfacial wave due to the bottom permeability. The matched eigenfunction expansion method and the least square technique are used to calculate various hydrodynamic coefficients. Wave energy identity relation is derived for the scattering scenario, and the associated energy loss due to the barrier is calculated. In order to attain the maximum wave dissipation, an ideal porous-effect parameter of the barrier is proposed for consideration, and it is observed that larger values of porous-effect parameter result in the lowest feasible pressure distribution. A good comparison with a prior result justifies the current semi-analytical procedure. Furthermore, the verification of the energy-identity terms aid in the validation of the computed results. Additionally, wave trapping in a confined region is examined by investigating reflection coefficients by considering a rigid wall. The thin perforated barrier model is further considered for examining the radiation aspect while considering its slow motion. For various porous-effect parameters of the barrier, the amplitude ratio of the radiated potential is investigated, and it is clearly observed that higher frequency significantly lowers the amplitude for both free surface and interfacial propagating modes. The impact of the perforated barrier is analysed by investigating the essential hydrodynamic coefficients, namely, added mass and damping coefficient.
{"title":"A mathematical study of water wave interaction with a thin perforated barrier in a two-layer fluid over a permeable bottom","authors":"Koushik Kanti Barman, S. Bora","doi":"10.1177/14750902231161120","DOIUrl":"https://doi.org/10.1177/14750902231161120","url":null,"abstract":"This article studies the impact of a submerged interface-piercing perforated barrier in a two-layer fluid flowing over a permeable bottom. We investigate oblique wave scattering, trapping and radiation due to the structure focusing on the bottom permeability. The dead water phenomenon is analysed with the consideration of the bottom permeability, which results in a higher variation of the interfacial wave due to the bottom permeability. The matched eigenfunction expansion method and the least square technique are used to calculate various hydrodynamic coefficients. Wave energy identity relation is derived for the scattering scenario, and the associated energy loss due to the barrier is calculated. In order to attain the maximum wave dissipation, an ideal porous-effect parameter of the barrier is proposed for consideration, and it is observed that larger values of porous-effect parameter result in the lowest feasible pressure distribution. A good comparison with a prior result justifies the current semi-analytical procedure. Furthermore, the verification of the energy-identity terms aid in the validation of the computed results. Additionally, wave trapping in a confined region is examined by investigating reflection coefficients by considering a rigid wall. The thin perforated barrier model is further considered for examining the radiation aspect while considering its slow motion. For various porous-effect parameters of the barrier, the amplitude ratio of the radiated potential is investigated, and it is clearly observed that higher frequency significantly lowers the amplitude for both free surface and interfacial propagating modes. The impact of the perforated barrier is analysed by investigating the essential hydrodynamic coefficients, namely, added mass and damping coefficient.","PeriodicalId":20667,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment","volume":"121 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91328705","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 : 2023-03-20DOI: 10.1177/14750902231162171
T. Nguyen, Tien-Hung Hou, Hai-An Pham, Chia-Cheng Tsai
In this study, an integrated model is developed for studying the Sanchi oil spill event, which occurred in the East China Sea in January 2018. The results of the Advanced Research Weather Research and Forecasting model (WRF-ARW) as well as the Princeton Ocean Model (POM) are used for meteorological forecasting and the hydrodynamic simulations, respectively. These data are adopted as inputs for the OpenOil, a sub-module of OpenDrift, for the oil spill model. Some reference experiments are examined for short-term hindcast. The satellite image is used to validate the numerical result. The oil slicks of the satellite image and the numerical result are of similar shapes. Quantitatively, the simulated oil slick and that from the satellite image are located closely and have similar dimensions of 56 km by 34 km and 54 km by 29 km, respectively. It is found that the accurate results can be obtained by the proposed integrated model with the high-frequency (hourly) and high-spatial-resolution data as inputs, and the wind drift factor has to be added. The long-term 1-month simulation showed that most of the oil particles would move to the northeast of the sinking location and be trapped by the Kuroshio current.
本文以2018年1月发生在东海的桑吉溢油事件为研究对象，建立了一个综合模型。先进研究天气研究与预报模式(WRF-ARW)和普林斯顿海洋模式(POM)的结果分别用于气象预报和水动力模拟。这些数据作为OpenDrift的子模块OpenOil的输入，用于漏油模型。对短期预报进行了一些参考实验。利用卫星图像对数值结果进行了验证。卫星图像上的浮油与数值计算结果的形状相似。从数量上看，模拟浮油与卫星图像上的浮油位置接近，尺寸相似，分别为56 km × 34 km和54 km × 29 km。结果表明，以高频(时)和高空间分辨率数据为输入，在加入风漂移因子的情况下，所提出的综合模式可以获得较准确的结果。长期1个月的模拟结果表明，大部分浮油颗粒会向下沉位置的东北方向移动，并被黑潮困住。
{"title":"Hindcast of oil spill pollution in the East China Sea in January 2018","authors":"T. Nguyen, Tien-Hung Hou, Hai-An Pham, Chia-Cheng Tsai","doi":"10.1177/14750902231162171","DOIUrl":"https://doi.org/10.1177/14750902231162171","url":null,"abstract":"In this study, an integrated model is developed for studying the Sanchi oil spill event, which occurred in the East China Sea in January 2018. The results of the Advanced Research Weather Research and Forecasting model (WRF-ARW) as well as the Princeton Ocean Model (POM) are used for meteorological forecasting and the hydrodynamic simulations, respectively. These data are adopted as inputs for the OpenOil, a sub-module of OpenDrift, for the oil spill model. Some reference experiments are examined for short-term hindcast. The satellite image is used to validate the numerical result. The oil slicks of the satellite image and the numerical result are of similar shapes. Quantitatively, the simulated oil slick and that from the satellite image are located closely and have similar dimensions of 56 km by 34 km and 54 km by 29 km, respectively. It is found that the accurate results can be obtained by the proposed integrated model with the high-frequency (hourly) and high-spatial-resolution data as inputs, and the wind drift factor has to be added. The long-term 1-month simulation showed that most of the oil particles would move to the northeast of the sinking location and be trapped by the Kuroshio current.","PeriodicalId":20667,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment","volume":"42 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82528831","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 : 2023-03-11DOI: 10.1177/14750902231157852
Mingyang Zhang, G. Taimuri, Jin-fen Zhang, S. Hirdaris
This paper presents a deep learning method for the prediction of ship motions in 6 Degrees of Freedom (DoF). Big data streams of Automatic Identification System (AIS), now-cast, and bathymetry records are used to extract motion trajectories and idealise environmental conditions. A rapid Fluid-Structure Interaction (FSI) model is used to generate ship motions that account for the influence of surrounding water and ship-controlling devices. A transformer neural network that accounts for the influence of operational conditions on ship dynamics is validated by learning the data streams corresponding to ship voyages and hydro-meteorological conditions between two ports in the Gulf of Finland. Predictions for a ship turning circle and motion dynamics between these two ports show that the proposed method can capture the influence of operational conditions on seakeeping and manoeuvring.
{"title":"A deep learning method for the prediction of 6-DoF ship motions in real conditions","authors":"Mingyang Zhang, G. Taimuri, Jin-fen Zhang, S. Hirdaris","doi":"10.1177/14750902231157852","DOIUrl":"https://doi.org/10.1177/14750902231157852","url":null,"abstract":"This paper presents a deep learning method for the prediction of ship motions in 6 Degrees of Freedom (DoF). Big data streams of Automatic Identification System (AIS), now-cast, and bathymetry records are used to extract motion trajectories and idealise environmental conditions. A rapid Fluid-Structure Interaction (FSI) model is used to generate ship motions that account for the influence of surrounding water and ship-controlling devices. A transformer neural network that accounts for the influence of operational conditions on ship dynamics is validated by learning the data streams corresponding to ship voyages and hydro-meteorological conditions between two ports in the Gulf of Finland. Predictions for a ship turning circle and motion dynamics between these two ports show that the proposed method can capture the influence of operational conditions on seakeeping and manoeuvring.","PeriodicalId":20667,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment","volume":"15 1","pages":"887 - 905"},"PeriodicalIF":1.8,"publicationDate":"2023-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90326921","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 : 2023-03-04DOI: 10.1177/14750902231157850
Kyung-Kyu Yang
In this study, the parameter sensitivity of the level 1 and 2 assessments of the excessive acceleration failure mode in the International Maritime Organization second-generation intact stability was analyzed. Monte-Carlo simulations were conducted using the input parameter space, which was generated using a Gaussian distribution, and a variance-based sensitivity analysis was performed using the Monte-Carlo simulation results. The longitudinal and vertical positions of the check point, natural roll period, and roll decay coefficient were selected as input parameters for the level 1 assessment, whereas the roll damping coefficient and effective wave slope coefficient replaced the roll decay coefficient for the level 2 assessment. The results revealed that the highest total sensitivity index for the level 1 assessment was the natural roll period, which was 0.8, and the effective wave slope had a total sensitivity index of 0.5 for the level 2 assessment. This indicated that the uncertainty of the natural roll period was dominantly propagated to the resultant value of the level 1 assessment, while the effective wave slope coefficient was the most sensitive parameter in the level 2 assessment. The uncertainty in the input variable was found to cause the opposite decision if the resultant value was close to the criterion value under a given loading condition.
{"title":"Parameter sensitivity of the excessive acceleration failure mode in second-generation intact stability","authors":"Kyung-Kyu Yang","doi":"10.1177/14750902231157850","DOIUrl":"https://doi.org/10.1177/14750902231157850","url":null,"abstract":"In this study, the parameter sensitivity of the level 1 and 2 assessments of the excessive acceleration failure mode in the International Maritime Organization second-generation intact stability was analyzed. Monte-Carlo simulations were conducted using the input parameter space, which was generated using a Gaussian distribution, and a variance-based sensitivity analysis was performed using the Monte-Carlo simulation results. The longitudinal and vertical positions of the check point, natural roll period, and roll decay coefficient were selected as input parameters for the level 1 assessment, whereas the roll damping coefficient and effective wave slope coefficient replaced the roll decay coefficient for the level 2 assessment. The results revealed that the highest total sensitivity index for the level 1 assessment was the natural roll period, which was 0.8, and the effective wave slope had a total sensitivity index of 0.5 for the level 2 assessment. This indicated that the uncertainty of the natural roll period was dominantly propagated to the resultant value of the level 1 assessment, while the effective wave slope coefficient was the most sensitive parameter in the level 2 assessment. The uncertainty in the input variable was found to cause the opposite decision if the resultant value was close to the criterion value under a given loading condition.","PeriodicalId":20667,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment","volume":"1 1","pages":"906 - 917"},"PeriodicalIF":1.8,"publicationDate":"2023-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79943600","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 : 2023-02-28DOI: 10.1177/14750902231157808
Kang Zhang, H. Cheng, Junpeng Liu, Haining Wang
Identifying the effect of thermal loads that are caused by temperature differences of inner and outer fluids on the structural sealing performance and strength is a long-standing quest in the design of subsea connectors. However, the structural stress and sealing parameters of the gasket under thermal loads are difficult to analyze and calculate using the current theoretical method because the boundary conditions of the gasket’s geometry surface are contact constraints interacted by the gasket and hubs. This paper presents an analytical calculation method (ACM) that evaluates the thermal-structural coupling strength and sealing performance considering such special boundary conditions. The thermal load is converted into an equivalent compression load, that is, a concentrated force, and applied to the contact region of the gasket. Additionally, a thermal-structural coupling finite element model is proposed to verify the ACM and the results show good agreement. Taken together, this work contributes to the design of subsea connectors that more likely take thermal loads into account.
{"title":"Analytical calculation method for predicting contact loads and structural strength of metallic gasket of subsea connectors under thermal loads","authors":"Kang Zhang, H. Cheng, Junpeng Liu, Haining Wang","doi":"10.1177/14750902231157808","DOIUrl":"https://doi.org/10.1177/14750902231157808","url":null,"abstract":"Identifying the effect of thermal loads that are caused by temperature differences of inner and outer fluids on the structural sealing performance and strength is a long-standing quest in the design of subsea connectors. However, the structural stress and sealing parameters of the gasket under thermal loads are difficult to analyze and calculate using the current theoretical method because the boundary conditions of the gasket’s geometry surface are contact constraints interacted by the gasket and hubs. This paper presents an analytical calculation method (ACM) that evaluates the thermal-structural coupling strength and sealing performance considering such special boundary conditions. The thermal load is converted into an equivalent compression load, that is, a concentrated force, and applied to the contact region of the gasket. Additionally, a thermal-structural coupling finite element model is proposed to verify the ACM and the results show good agreement. Taken together, this work contributes to the design of subsea connectors that more likely take thermal loads into account.","PeriodicalId":20667,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment","volume":"1 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79467420","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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