ISSN: 2147-2955 / E-ISSN: 2148-9386
Journal of ETA Maritime Science - JEMS Maritime Sci: 8 (1)
Volume: 8  Issue: 1 - 2020
EDITORIAL (ED)
1.Editorial
Selçuk Nas
Page 1
Abstract | Full Text PDF

FULL TEXT
2.Journal of ETA Maritime Science (Volume: 8 Issue: 1, 2020)

Pages 1 - 84
Abstract | Full Text PDF

INDUSTRIAL PERSPECTIVE
3.Understanding IMO 2020
Ada Ezgi Başer
doi: 10.5505/jems.2020.06025  Pages 2 - 9
Abstract | Full Text PDF

ORIGINAL RESEARCH (AR)
4.TC-UV Reactor Evaluated as an Alternative Option for Treatment of Ballast Water
Hüseyin Elçiçek, Bülent Güzel
doi: 10.5505/jems.2020.84803  Pages 10 - 21
Son yıllarda UV dezenfeksiyon teknolojisi özellikle kentsel ve endüstriyel atık suların patojenik ve istenmeyen türlerin dezenfeksiyonun da yaygın olarak kullanılmaktadır. Bu çalışmada, balast suyunda yaygın olarak bulunan yabancı türlerin dezenfeksiyonunda Taylor-Couette UV reaktörünün uygulanabilirliği araştırılmıştır. Bu amaçla iki farklı yarıçap oranına sahip bir Taylor-Couette reaktöründe gliserol çözeltisi kullanılarak, reaktör içerisinde ortaya çıkan akış yapıları gözlemlenmiş ve kritik geçiş değerleri literatür verileri ile karşılaştırılmıştır. TC reaktöründe ortaya çıkan vorteks yapıları, akışkan karışımın iyileşmesine ve E. coli dezenfeksiyon verimliliğinin ve UV dezenfeksiyon ünitesinin performansının arttırılmasında önemli katkı sağlamaktadır. Elde edilen sonuçlar, balast suyu içerisinde bulunan istenmeyen türlerin dezenfeksiyonunda Taylor-Couette UV reaktörünün alternatif bir yöntem olarak kullanılabileceğini göstermektedir.
Over the last decade, UV disinfection technology has been widely employed in the disinfection of non-native species in wastewater and process water treatment. In this study, we assessed the feasibility of the adoption of a Taylor-Couette UV reactor in disinfection of unwanted species commonly found in ballast water. With this purpose, glycerol solutions were used in a Taylor Couette reactor with two different radius ratios. The observed flow structures and the critical transition values were simultaneously compared with each other and literature. Emergent flow structures in TC reactors provide considerable improvement in axial and radial mixing of particles and increasing the efficiency of the disinfection of E. coli. The obtained results show the possibility of utilizing the Taylor-Couette UV reactors as an alternative method in inactivation of non-native species in the ballast water.

5.A Study on Working and Living Conditions of Turkish Seafarers
Özgür Tezcan, Erdem Kan, Oğuz Atik
doi: 10.5505/jems.2020.28290  Pages 22 - 37
In order to increase the number of well-qualified and well experienced seafarers on ships and their employment periods, as well as providing the desired safety at work, improving/promoting the working conditions on ships, is of utmost significance. The purpose of this study is to reveal to what extent working conditions for Turkish seafarers who work on commercial ships comply with the terms of MLC (Maritime Labour Convention). For this aim, a questionnaire, an instrument of quantitative research method, has been issued and conducted through 296 seafarers working on the ships owned by Turkish shipowners. The results of comparative analysis reveal that the working condition on Turkish-owned ships are moderately compliant with the terms of MLC.
In order to increase the number of well-qualified and well experienced seafarers on ships and their employment periods, as well as providing the desired safety at work, improving/promoting the working conditions on ships, is of utmost significance. The purpose of this study is to reveal to what extent working conditions for Turkish seafarers who work on commercial ships comply with the terms of MLC (Maritime Labour Convention). For this aim, a questionnaire, an instrument of quantitative research method, has been issued and conducted through 296 seafarers working on the ships owned by Turkish shipowners. The results of comparative analysis reveal that the working condition on Turkish-owned ships are moderately compliant with the terms of MLC.

6.Analyzing the Effect of Fuel Injection Timing and Injection Duration on Performance and Emissions in Diesel Engines
Kubilay Bayramoğlu, Mustafa Nuran
doi: 10.5505/jems.2020.99705  Pages 38 - 52
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.

7.Investigation of the Effect of Leading Edge Tubercles on Wingsail Performance
Harun Kemali, Ahmet Ziya Saydam, Şebnem Helvacıoğlu
doi: 10.5505/jems.2020.60490  Pages 54 - 65
Bu çalışmada 2013 yılı Amerika Kupasında kullanılan kanat tipi yelkenlerin orsa yakasında ki yumruların etkisi, viskoz Hesaplamalı Akışkanlar Dinamiği (HAD) ile incelenmiştir. Yelkenlerin önder kenarına yumruların eklenmesi fikri, kendine özgü yüzgeçleri sayesinde hızlı ve yüksek manevra yeteneğine sahip canlılar olan kambur balinalardan esinlenilmiştir. Yapılan bilimsel çalışmalar, yüksek hücum açılarında, önder kenar yumrularının tutunma kaybını (stall) geciktirdiği, düz kanatlara göre daha iyi kaldırma-kuvveti/direnç oranı sağladığı görülmüştür.
2013 Amerika Kupası teknesine ait bir kanat yelken geometrisi, performansa yumruların etkisini ölçme amaçlı olarak geliştirilmiştir. Önder kenara, profil (kord) boyunun fonksiyonu olacak şekilde, farklı dalga boyu ve genlikte sinüzoidal yumrular yerleştirilmiştir. Yumruların kanat yelken üzerinde tutunma kaybının başladığı açıdan sonra kaldırma kuvvetini arttırdığı ve performansa olumlu katkı sağladığı görülmüştür.
In this study, effects of leading edge tubercles on a 2013 America’s Cup boat wingsail are investigated by viscous Computational Fluid Dynamics (CFD). Adding tubercles on the leading edge of the sail is inspired by humpback whales, which are fast and maneuverable animals along baleen whales thanks to their distinctive flippers. It has been seen from the examined studies that tubercles on the leading edge of the wings delay stall and provide better lift/drag ratio in high angle of attacks (AoA) compared to the plain wing, which might be beneficial for wingsails.
A 2013 America’s Cup boat wingsail geometry is developed for measuring the effects of tubercles on its performance. Sinusoidal tubercles are placed on leading edge with different wave lengths and amplitudes varying as a function of chord length. Post-stall performance of the wingsail has been improved whereas onset of stall has been observed to be identical to that of the base wingsail.

8.An exploratory study on the perceptions of stakeholders in LNG Bunkering Supply Chain
Mehmet Doymus, Gul Denktas Sakar
doi: 10.5505/jems.2020.43255  Pages 66 - 84
’IMO 2020 regulations force maritime industry to look for alternative fuels for compliance. LNG is a promising option as a fuel considering today's emission control regulations and for measures to be adopted in the future. However, supply chain development for small-scale LNG is not at the expected level. The study examines the development of LNG bunkering supply chain based on different perspectives of stakeholders. The research explores the challenges regarding LNG bunkering development and aims to provide suggestions to overcome these challenges. Semi-structured interviews were conducted through purpose sampling including various representatives of LNG bunkering supply chain. The study identifies barriers in LNG bunkering development, categorizes some key approaches and links challenges from the view point of relevant stakeholders for improvement in supply chain. The research findings indicate that collaboration of stakeholders is the main driver for LNG bunkering development, public opinion, standardisation and transparency are the other outstanding factors to improve LNG bunkering supply chain.

LookUs & Online Makale