Akin Kutlar | Istanbul Technical University (original) (raw)

Papers by Akin Kutlar

Fen Bilimleri Enstitüsü, 1999

Materials Testing, 2019

In this study, the eccentric shaft of a 13B MSP (Multi Side Port) single-rotor Wankel test engine... more In this study, the eccentric shaft of a 13B MSP (Multi Side Port) single-rotor Wankel test engine was examined. The eccentric shaft was studied in two parts, both through modeling and experimentally. The eccentric shaft was modeled via a workbench module using ANSYS software. Here, the shaft was modeled according to the original dimensions at different speeds ranging from 1000 to 10000 rpm under different operating temperatures (25, 50 and 90 °C). In the analysis, von Mises stress and corresponding deformations were examined under the specified conditions. Afterwards, the stress and deformation of the eccentric shaft were experimentally investigated in engine tests performed at low loads and speeds. The eccentric shaft broke after approximately 200 hours. It was found that broken region was specified to critical points for validity of the applied model used in the current study. Thus, it was shown deformation and stress values can be predicted by numerically modeling the eccentric s...

Energies, 2019

The results of experiments performed by gasoline and natural gas fuels in a single cylinder resea... more The results of experiments performed by gasoline and natural gas fuels in a single cylinder research engine were evaluated in this study. The main objective of this study is to compare exhaust gas emissions, efficiency, and burn durations for both fuels in stoichiometric and lean mixture. At the same time, cycle to cycle variation in these operating conditions should not exceed an acceptable value. In the ultra-lean mixture, gasoline fuel exceeded this determined limit before Compressed Natural Gas (CNG). Therefore, the reduction in NO was restricted by cyclic variations. In combustion analysis, although the burn duration of the gasoline in stoichiometric conditions was shorter than CNG, this situation reversed in favor of CNG in the ultra-lean mixtures. Contrary to some studies in the literature, the spark advance and ignition delay for CNG were the same or shorter than gasoline in this study. The primary reasons for this change are the high compression ratio and the different comb...

Skip cycle is a working strategy for spark ignition engines, which allows changing the effective ... more Skip cycle is a working strategy for spark ignition engines, which allows changing the effective stroke of an engine through skipping some of the four stroke cycles. This study proposes a new mechanism to achieve the desired skip-cycle strategy for internal combustion engines. The air and fuel leakage, which occurs through the gas exchange, negatively affects the efficiency of the engine at high speeds and loads. An absolute sealing is assured by direct use of poppet valves, which are kept in fully closed position during the skipped mode. All the components of the mechanism were designed according to the real dimensions of the Anadolu Motor's gasoline engine and modeled in 3D by means of CAD software. As the mechanism operates in two modes, two dynamically equivalent models are established to obtain the force and strength analysis for critical components.

One of the most difficult problems to be resolved during the development of diesel engines is to ... more One of the most difficult problems to be resolved during the development of diesel engines is to decrease nitrogen oxides, soot (smoke) and particulates in exhaust emissions, without decreasing performance and efficiency, to limits proposed by emission standards, which will be in force in near future. During last years by cooperation and projects with different engine manufacturers Istanbul Technical University developed new fuel-air formation and combustion mechanism that is used in actual combustion chambers of diesel combustion engines. In this paper are presented some theoretical and test results of diesel engines developed by applying this new mechanism.

One of the most difficult problems to be resolved in development of diesel engines is to decrease... more One of the most difficult problems to be resolved in development of diesel engines is to decrease nitrogen oxides, soot (smoke) and particulates in exhaust emissions, without decreasing performance and efficiency, to limits proposed by emission standards which have being more and more stricter. As in developed European countries, by taking in force the 2004/26/EC standard in Turkey the dense research and development activities and practical usage of their positive results is occurred as a problem to be solved in future 2-3 years in developments of offroad vehicle’s engines. During last years by cooperation and projects with one of the biggest internal combustion engine manufacturers TUMOSAN and other factories Istanbul Technical University developed new combustion mechanisms that are used in actual CCs. In this paper are presented some theoretical and test results obtained during the development of TUMOSAN’s diesel engines.

The main process which is directly related with the improvement of performance, fuel economy and ... more The main process which is directly related with the improvement of performance, fuel economy and emission characteristics of an internal combustion engine is the combustion process itself. In order to find an optimum combustion process that meets these demands a simple Vibe based theoretical computation model was first established. Using this theoretical model some results are obtained and presented in this study. A construction of a suitable combustion chamber that will realize this process is designed and tested in a single cylinder experimental diesel engine. Experiment results of this novel combustion chamber are presented and compared with those results obtained from engine equipped with the standard combustion chamber. Indicated cylinder pressure and related pressure rise and heat release curves of the novel combustion chamber are compared with those of standard engine combustion chamber. The comparison of both type diesel engines is done at the same original maximum power. Th...

Arabian Journal for Science and Engineering, 2021

The aim of this study was to determine the ignition advance difference between the leading and tr... more The aim of this study was to determine the ignition advance difference between the leading and trailing spark plugs found in the 13B-MSP (Multi Side Port) Wankel engine. The optimum ignition advance difference between the two-spark plugs had been determined by examining brake specific fuel consumption, emissions, p–V diagram, cumulative heat release rate and cyclical variations on the engine. Better results were obtained, if the advance difference was 15 or 20° in terms of total hydrocarbon and brake specific fuel consumption. It was observed that as the ignition advance difference decreased between the two-spark plugs, the combustion started earlier and completed in a short time, and when the ignition advance difference increased, the combustion started later and slower. Therefore, combustion improved with the ignition advance difference being 15°. The average of maximum pressures for 200 cycles was found as 20.48 bar, 26.11 bar and 17.36 bar in 5°, 15° and 30° ignition advance differences, respectively. 15° ignition advance difference was found to be faster to burn than other advance differences. It was observed that the optimum advance difference between the leading and trailing spark plugs should be 15°. Subsequently, single-spark plug (Trailing plug) and two-spark plug (Trailing + Leading plug) experiments were performed on different loads. As a result, two-spark plug compared to single-spark plug, fuel consumption and emissions decreased, and it was observed that combustion became better by increasing in-cylinder pressure and heat release rate.

Konya Journal of Engineering Sciences, 2020

Gazi Üniversitesi Mühendislik-Mimarlık Fakültesi Dergisi, 2020

In this paper, the effects of biodiesel on performance and emission of the current and new-coming... more In this paper, the effects of biodiesel on performance and emission of the current and new-coming regulation cycles, namely the New European Driving Cycle (NEDC) and the Worldwide Harmonized Light Vehicles Test Cycle (WLTC), were investigated by conducting tests on a passenger car, Euro-5 Ford Fiesta, equipped with a 1.5-liter diesel engine. In a two-axle chassis dynamometer test bed, NEDC and WLTC were performed with pure diesel and biodiesel-to-diesel blend (30% biodiesel, 70% diesel in volume). A substantial reduction in CO, HC, and PN emissions was observed for both the NEDC and WLTC when biodiesel was used. Besides, it was found that the WLTC has higher load and velocity profile compared to the NEDC. Moreover, lower CO, HC, and PN emissions were observed with B30 fuel under WLTC compared to the NEDC. Nevertheless, slightly higher CO2 and substantially higher NOx emissions were observed for the WLTC compared to the NEDC.

SAÜ Fen Bilimleri Enstitüsü Dergisi, 2017

World Renewable Energy Congress VI, 2000

Publisher Summary This chapter discusses the methods of hydrogen production, distribution, and st... more Publisher Summary This chapter discusses the methods of hydrogen production, distribution, and storage of hydrogen in comparison to other energy sources and advances in these fields. Expectations from hydrogen as an alternative automotive fuel in the future are examined. The use of renewable energy sources for vehicles became more attractive as new technologies increase energy efficiency and decrease costs. Alternative electric power technologies include hydroelectric, wind driven turbines, solar power, and geothermal sources. Alternative renewable fuels include ethanol, methanol, methane, hydrogen, and others. Meanwhile, fossil fuels are a limited resource, and their combustion products pollute the environment with a variety of harmful compounds. The use of hydrogen as a fuel in internal combustion engine presents some more engineering challenges, but recent efforts have shown that none of the problems are insurmountable and the benefits outweigh the limitations.