Çevreye zarar vermeden üretilecek enerji günümüz insanlarinin en önem verdigi konular arasinda yer almaktadir. Bu yüzden, yenilenebilir enerji sistemlerinin geleneksel enerji sistemlerinin yerini almasi gerektigi görüsü öne çikmaktadir. Hangi yenilenebilir enerji sisteminin bir bölge için daha sürdürülebilir olduguna karar verebilmek için kullanilan en önemli yöntemlerden biri yasam döngüsü analizleri olarak karsimiza çikmaktadir. Yasam döngüsü degerlendirmesi (YDD), enerji üretim süreçlerinin tüm çevresel etkilerini incelemek üzere yaygin kullanilan bir yöntemdir. Bu yöntem; üretim, insaat, isletme-bakim ve tasfiye-geri dönüsüm evrelerinin incelenmesinden olusmaktadir. Bu çalismada, iki farkli yenilenebilir enerji sistemi konfigürasyonu YDD metodu ile karsilastirilmis olup, incelenen yenilenebilir enerji sistemlerinin dört fazi ele alinacak sekilde yasam döngüleri çevresel açidan degerlendirilmistir. Seçilen sistemlerden ilki karasal rüzgâr santrali, ikincisi ise deniz üstü rüzgâr santralidir. Bu amaçla, Bozcaada bölgesi, pilot bölge olarak seçilmis; Bozcaada’da 2000 senesinden beri isletilen karasal rüzgâr çiftligi ile bu bölgenin rüzgâr potansiyelinden daha fazla faydalanabilmek adina ayni bölgede kurulmasi muhtemel deniz üstü rüzgâr santrali incelenmistir. Her iki konfigürasyon için de, enerji üretim süreçlerinin besikten mezara degerlendirilmesinde Gabi yazilimi kullanilmistir. Ekonomik açidan karsilastirma yapabilmek adina ise, her iki sistemin yasam döngüsü maliyeti (YDM) hesaplanmistir. Yasam Döngüsü Degerlendirmesi (YDD) ve Yasam Döngüsü Maliyeti (YDM) analiz yöntemleri bir bölge için düsünülen farkli yenilenebilir enerji sistemlerinin uzun dönemdeki ekonomik ve çevresel etkilerini belirlemek açisindan pratik yöntemler olabileceginden her iki sistem için analizler yapilmis ve bu analizlerin kiyaslamasi gerçeklestirilmistir. Elde edilen bulgular isiginda, deniz üstü rüzgâr çiftliginin daha maliyetli bir teknoloji olmasina ragmen, (asitlestirme haricinde) daha çevre dostu bir sistem oldugu sonucuna ulasilmistir. Sonuç olarak, deniz üstü rüzgâr santralinin Bozcaada bölgesi için çevresel olarak daha uygun oldugu görülmüstür.

Search and rescue operations intend to save the lives of people in need of emergency assistance who have been endangered by natural disasters or any other unwanted cause. Especially in marine accidents, due to the challenging conditions of the marine environment and the specific rules of the maritime, search and rescue activities to be implemented require complex needs such as legal and operational infrastructure, organization within the public sector, qualified personnel, effective communication and reporting system, international level cooperation. Taking into consideration this situation, countries can establish search and rescue organizations at sea and determine search and rescue zones in the surrounding seas in their own internal legal regulations in order to save human life. As search and rescue is a service area aiming to ensure the safety of casualties, states can carry out these activities only within the framework of their organic organizations, as well as providing search and rescue services within the framework of agreements made with other states. In previous years search and rescue operations that carried out at sea were executed with the perception of rescue of survivors after ship accidents. However, due to the worldwide economic imbalances in recent years, the mass deaths caused on illegal irregular migration done by people trying to cross from Middle East and North Africa to Europe have increased the importance of search and rescue activities. These incidents are handled in terms of security in order to prevent immigrants who try to cross the maritime border, and in terms of safety in order to ensure the safety of these people. In this study, the Turkish Search and Rescue Organization, which was established in order to prevent in marine accidents, was introduced and the cooperation activities and conflicts with other countries and organizations for marine search and rescue regions, which were determined in accordance with national and international legal regulations, were presented. Document Review Method was used while researching article subjects.

This study aims to propose a fast calculation method to evaluate the total resistance of a traditional ship hull form. It became a common knowledge nowadays that the computational fluid dynamics (CFD) approach is robust in calculating the frictional resistance component of a ship with double body flow solutions. Modeling of the free surface is still a problematic issue due to the mathematical background of the Volume of Fluid (VOF) approach and even if a good match is obtained with experiments, these multiphase computations consume a lot of time and need higher computational power. To circumvent this problem, this study proposes a hybrid CFD-empirical approach. The results of the single phase computations obtained by CFD is coupled with the empirical approach of Holtrop-Mennen. The frictional and viscous pressure resistances of a benchmark ship (Duisburg Test Case – DTC) were calculated by CFD and using the wave resistance values of the Holtrop-Mennen resistance calculation method, the total resistance was obtained. To assess double body solutions dominated by viscosity, two different turbulence models were evaluated in the process. It was found out that k-omega turbulence model generated slightly better results compared to the k-epsilon according to the reference experiments.

Today, there are hundreds of different systems for ballast water treatment and the selection of the most suitable system for a specific vessel is an increasingly important issue as the Convention nears enforcement on 8 September 2017. The goal of this study is to demonstrate that Key Performance Indicator (KPI) application for Ballast Water Treatment (BWT) System selection is a very useful tool enabling shipyards to compare BWT systems to make better choices and to designate the most adequate system for their ships. In this study two types of vessels from a shipyard in Istanbul-Turkey with different ballast water capacities and equipment are examined and the most suitable systems are selected by using the KPI method.

Consistent determination of unknown values ??based on statistical data at the concept design stage is a widely used approach. It is clear that the determination of the main dimensions and capacities of the ships in the conceptual design phase at an acceptable accuracy is decisive for the success of the next stages of the design as well as the bid preparation. For yachts, the main dimensions, areas and volumes of the decks forming the top building besides the main values ??such as ship size, width and depth directly affect the external design features and cost levels of such special boats. In the concept design phase, for example in the modeling of a characteristic such as stability, the minimization of the design variables to be used as much as possible gives the naval architect the ease of operation and the ability to control these variables more freely. In summary, it is aimed to present a simple and useful approach to the naval architect, which can be used during the conceptual design stage of mega yachts and yield an error level as low as possible. The resulting formula obtained from the method developed in this paper is given as follows: For F = 30: CRS . 103= For F > 30: CRS . 103=

In this study, turning circle and zig-zag test simulations for a fishing vessel form were carried out by using existing mathematical model and maneuvering derivatives in the literature. The simulations were performed for calm water conditions, that is, all external inputs such as wave, current, wind, ice loads, propeller etc. were neglected. The solution of the lateral plane motions in time domain were completed by using 4th order Runge-Kutta Method in Matlab-Simulink package program. It is possible to more effectively construct the maneuvering simulation in wavy environment on Matlab-Simulink interface if the external loads in irregular seas are known as a function of time. Simulink block diagrams prepared in the present study will allow a quick transition to such disturbance excitation damping studies in the future.

The use of submarines in military, touristic, oceanographic surveys and seashore areas has increased in recent years. Much of the scientific research in submarine hydrodynamics has focused on the issues of acoustics and propulsion. One of the most important differences from the submarine dimensions in determining the propulsion characteristics is to define the angle of the stern cone. In this study, the effect of stern cone angle and aspect ratio (L / B) on hull efficiency is investigated by a computational fluid dynamics method (HAD). DARPA Suboff submarine is derived for different stern cone and different L / B ratios, so that displacement volume remains constant. For different submarine geometries, resistance and propulsive properties were investigated by performing flow analysis with/without propeller. The effect on the propeller-body interaction of the stern cone is given as the thrust deduction, the effective wake coefficient and the hull efficiency.