Journal of ETA Maritime Science

1

Authors: Selçuk NAS

We are pleased to introduce JEMS 8(1) to our valuable followers. There are valuable and endeavored studies in this issue of the journal. We hope that these studies will contribute to the maritime industry. I would like to mention my gratitude to authors who sent their valuable studies for this issue, to our reviewers, to our editorial board, to our section editors, to our foreign language editors who provide quality publications by following our publication policies diligently and also to layout editors who spent great efforts in the preparation of this issue. Your Sincerely

10-21

Authors: Hüseyin ELÇİÇEK, Bülent GÜZEL

Over the last decade, UV disinfection technology has been widely employed in the disinfection of nonnative 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.

38-52

Authors: Kubilay BAYRAMOĞLU, Mustafa NURAN

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.

66-84

Authors: Mehmet DOYMUŞ, Gül DENKTAŞ ŞAKAR

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.