Journal of Eta Maritime Science最新文献_第10页

Investigation of the Effect of Number of Longitudinal Rounded Grooves on Hydrodynamic Forces acting on Cylinders in Cross Flow at Re=100000 Re=100000横流条件下纵向圆槽数对气缸水动力影响的研究

IF 0.9

Journal of Eta Maritime Science Pub Date : 2020-01-01 DOI: 10.5505/jems.2020.49354

Oktay Yilmaz

{"title":"Investigation of the Effect of Number of Longitudinal Rounded Grooves on Hydrodynamic Forces acting on Cylinders in Cross Flow at Re=100000","authors":"Oktay Yilmaz","doi":"10.5505/jems.2020.49354","DOIUrl":"https://doi.org/10.5505/jems.2020.49354","url":null,"abstract":"Crossflow over cylindrical structures has been extensively studied by both academia and industry in various fields. It is responsible for in-line and transverse vibrations of marine risers. Flow-induced structural vibrations may end up with the failure of these tubular systems in oceans and seas. First experimental studies in literature signified that longitudinally grooved cylinders inspired by Saguaro trees may offer reductions both in drag and lift forces. In the present study, the performance of 2 dimensional (2D) unsteady Reynolds averaged Navier-Stokes (URANS) simulations is tested in predicting hydrodynamic force coefficients of cylinders. First, CFD runs are conducted on a smooth cylinder and a cactus-like cylinder in literature. Then flow over 8-, 10-, and 12-grooved cylinders with a diameter of 0,5 m are solved to analyze flow features in detail and evaluate the capability of 2D URANS solver for the problem at hand. k-ω SST turbulence model is employed in URANS solver. It is shown that as the number of grooves increases, mean drag slightly decreases and amplitude of drag decreases by 29%. Separation angle is significantly improved with a number of grooves from 92o to 120o. However, the amplitude of lift force increases with the number of grooves with reference to 2D CFD simulations.","PeriodicalId":41280,"journal":{"name":"Journal of Eta Maritime Science","volume":"8 1","pages":"178-193"},"PeriodicalIF":0.9,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71090105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Is Existing Maintenance System Adequate for Sulphur 2020 Amendments? 现有维修系统是否足以应付硫磺2020修订?

IF 0.9

Journal of Eta Maritime Science Pub Date : 2020-01-01 DOI: 10.5505/jems.2020.89421

Ahmet Yaşar Canca, Görkem Kökkülünk

引用次数: 3

Prediction of Ship Main Engine Failures by Artificial Neural Networks 基于人工神经网络的船舶主机故障预测

IF 0.9

Journal of Eta Maritime Science Pub Date : 2020-01-01 DOI: 10.5505/jems.2020.90377

Burak Göksu, K. E. Erginer

{"title":"Prediction of Ship Main Engine Failures by Artificial Neural Networks","authors":"Burak Göksu, K. E. Erginer","doi":"10.5505/jems.2020.90377","DOIUrl":"https://doi.org/10.5505/jems.2020.90377","url":null,"abstract":"Maintenance practices are considered as the means of providing safety and security to environment and quality service, and despite increasing the costs for companies with certain increments, they contribute to their reputation and reliability. Maintenance planning of ships consists of setting priorities and planning the efficient use of the sources. One of the main objectives of this study is to bring up more profits from commercial activities by optimizing the availability of vessels. Operational capacity is ensured by adopting a systematic and proper maintenance policy that increases effectiveness and efficiency by reducing downtime. To reach at such a target, recent failure data is analyzed and through this analysis certain procedures are developed for spare parts availability and these procedures are utilized in maintenance applications. This study aims to provide an additional feature for predictive maintenance software for the analysis of the upcoming conditions of the main engine systems. In this study, the history of failure in the critical nine main engine related subsystems have been analyzed by artificial neural network method, which is consistent with condition-based maintenance applications and subsequently helps to bring out the potential breakdowns in the recorded history of failure.","PeriodicalId":41280,"journal":{"name":"Journal of Eta Maritime Science","volume":"8 1","pages":"98-113"},"PeriodicalIF":0.9,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71090422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7

Analyzing the Effect of Fuel Injection Timing and Injection Duration on Performance and Emissions in Diesel Engines 分析喷油时机和喷油时间对柴油机性能和排放的影响

IF 0.9

Journal of Eta Maritime Science Pub Date : 2020-01-01 DOI: 10.5505/jems.2020.99705

Kubilay Bayramoğlu, M. Nuran

{"title":"Analyzing the Effect of Fuel Injection Timing and Injection Duration on Performance and Emissions in Diesel Engines","authors":"Kubilay Bayramoğlu, M. Nuran","doi":"10.5505/jems.2020.99705","DOIUrl":"https://doi.org/10.5505/jems.2020.99705","url":null,"abstract":"Fossil-based fuels have been decreasing all over the world and the energy requirements of power generation systems are increasing. Diesel engines are one of the most common and efficient power generation systems. However, national and international organizations impose various restrictions to reduce emissions from diesel engines. Reducing emissions and improving performance in diesel engines are one of the most common areas of work. Improvement of performance and emission parameters is possible with changes in alternative fuels, engine geometry and fuel injection systems. In this study, the effects of different injection timing and injection duration on diesel engine performance and exhaust gas emissions have been investigated with computational fluid dynamics (CFD) method. The numerical study has been carried out on a 4-stroke, single cylinder test engine and the results have been compared with the experimental results obtained from the literature. As a result of the study, combustion chamber speed profiles, fuel mass change, temperature, pressure, chemical heat release rate has been determined for the standard operating conditions. Parametric study has been performed for different injection timing and injection duration of engine. For each case, performance and emissions parameters have been determined. Analysis results has compared, and the most suitable injection parameters has been introduced.","PeriodicalId":41280,"journal":{"name":"Journal of Eta Maritime Science","volume":"8 1","pages":"38-52"},"PeriodicalIF":0.9,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71090228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 6

A Study on Working and Living Conditions of Turkish Seafarers 土耳其海员的工作和生活条件研究

IF 0.9

Journal of Eta Maritime Science Pub Date : 2020-01-01 DOI: 10.5505/jems.2020.28290

Ö. Tezcan, Erdem Kan, Oğuz Atik

引用次数: 2

An exploratory study on the perceptions of stakeholders in LNG Bunkering Supply Chain LNG加注供应链中利益相关者认知的探索性研究

IF 0.9

Journal of Eta Maritime Science Pub Date : 2020-01-01 DOI: 10.5505/jems.2020.43255

Mehmet Doymus, G. Şakar

引用次数: 2

Quantitative Analysis of Dynamic Risk Factors for Shipping Operations 航运作业动态风险因素定量分析

IF 0.9

Journal of Eta Maritime Science Pub Date : 2020-01-01 DOI: 10.5505/jems.2020.63308

Serap Göksu, O. Arslan

引用次数: 6

Analysis of Operational Performance of Crude Oil Refining and Petrochemical Jetties in Nigeria 尼日利亚原油炼化码头运行性能分析

IF 0.9

Journal of Eta Maritime Science Pub Date : 2020-01-01 DOI: 10.5505/jems.2020.98705

Donatus Eberechukwu Onwuegbuchunam, M. Aponjolosun, S. Buhari, D. Ojo

{"title":"Analysis of Operational Performance of Crude Oil Refining and Petrochemical Jetties in Nigeria","authors":"Donatus Eberechukwu Onwuegbuchunam, M. Aponjolosun, S. Buhari, D. Ojo","doi":"10.5505/jems.2020.98705","DOIUrl":"https://doi.org/10.5505/jems.2020.98705","url":null,"abstract":"This paper assessed the performance of jetty operations in Warri Refining and Petrochemical Company (WRPC). Primary data for the study consisted of ship turn round times, volume of cargo and number of vessels handled at the jetties for years 2004 to 2018. These variables served as key performance assessment criteria. In addition, copies of questionnaires on postulated factors affecting terminal performance were administered to a random sample of WRPC staff. Our findings showed that the jetties were being operated at less than optimum level. Trend analysis of the key performance indicators showed existence of continuous decline in operational performance of WRPC over the years covered in the study. Significant factors accounting for this performance outcome were found to include: inadequate berthing facilities, shortage of manpower supply, pipeline vandalisation, inadequate maintenance of jetty facilities and poor documentation process. The study recommended deployment of trained workforce to jetty operations, maintenance of berthing facilities, adequate funding and improved documentation of processes during jetty operations.","PeriodicalId":41280,"journal":{"name":"Journal of Eta Maritime Science","volume":"1 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71090132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Weighting Key Factors for Port Congestion by AHP Method 用AHP方法加权港口拥塞关键因素

IF 0.9

Journal of Eta Maritime Science Pub Date : 2020-01-01 DOI: 10.5505/jems.2020.64426

P. Bolat, Gizem Kayisoglu, Emine Gunes, Furkan Eyup Kizilay, Soysal Ozsogut

引用次数: 6

Dimensions of the Port Performance: A Review of Literature 港口绩效的维度:文献综述

IF 0.9

Journal of Eta Maritime Science Pub Date : 2020-01-01 DOI: 10.5505/jems.2020.76598

U. Bucak, Ibrahim Basaran, Soner Esmer

引用次数: 5