Person: YILMAZ, İLKER TURGUT
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YILMAZ
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İLKER TURGUT
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Publication Metadata only Assessment of combustion and exhaust emissions in a common-rail diesel engine fueled with methane and hydrogen/methane mixtures under different compression ratio(PERGAMON-ELSEVIER SCIENCE LTD, 2020) YILMAZ, İLKER TURGUT; Sanli, Ali; Yilmaz, Ilker Turgut; Gumus, MetinThis study investigates the potential usage of the methane and hydrogen enriched methane in a turbocharged common-rail direct injection diesel engine. Methane and hydrogen/methane mixtures are sent through the air intake manifold of the engine. The engine is operated at four different loads and three different compression ratios. Results are compared amongst single diesel and dual-fuel operations at different compression ratios and load conditions. Compared to diesel, dual-fuel operations mostly generate higher and advanced peak in-cylinder gas pressure, more combustion noise, late pilot injection and start of combustion, advanced combustion center, substantial variations at ignition delay and combustion duration, a significant increase in cyclic variations at low and medium loads, and earlier heat release. Hydrogen enrichment decreases evidently specific fuel consumption. Concerning emissions, compared to diesel operation, dual-fuel operations produce higher total hydrocarbon (THC) and nitrogen oxides (NOx) but lower carbon dioxide (CO2). Hydrogen substitutions decrease THC and CO2 emissions of methane dual-fuel operations approximately between 9-29% and 1-32%, respectively. Smoke emission of dual-fuel operations is less than that of diesel at low and medium loads, whereas it sharply increases at high load. Knocking occurs at high compression ratio and load conditions with dual-fuel operations and dramatically increases with increasing hydrogen ratio. Decreasing the compression ratio notably reduces the combustion noise as well as some emissions, such as NOx, CO2 and smoke, for entire load ranges of dual-fuel and diesel operations. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.Publication Metadata only Effect of nheptane/isopropanol/butanol/diesel blends on exhaust emissions in a commonrail diesel engine(2022-07-08) SAYIN, CENK; VARGÜN, MUSTAFA; YILMAZ, İLKER TURGUT; Vargün M., Yapmaz A., Yılmaz İ. T., Sayın C.Publication Metadata only Use of catanol and waste engine oil blends in diesel engine(2022-07-08) YILMAZ, İLKER TURGUT; Başaran H. Ç., Yılmaz İ. T., Akçay M.Publication Metadata only Effect of hydrogen addition on performance and emission characteristics of a common-rail CI engine fueled with diesel/waste cooking oil biodiesel blends(PERGAMON-ELSEVIER SCIENCE LTD, 2020) FEYZİOĞLU, AHMET; Akcay, Mehmet; Yilmaz, Ilker Turgut; Feyzioglu, AhmetIn this study, the effect of hydrogen addition to a compression ignition (CI) engine fueled with the diesel fuel-waste cooking oil biodiesel (WCOB) blend (B25) on the engine performance, and exhaust emissions was examined experimentally. In the tests, a four-cylinder, four-stroke, water-cooled, 1.461-L, turbocharged CI engine was used. The engine tests were performed at the fixed engine speed of 1750 rpm and at the diverse engine loads of 40, 60 and 80 Nm. The hydrogen was added to the intake air at the flow rates of 10, 20, 30 and 40 lpm. According to the results obtained, hydrogen had a positive effect on break specific fuel consumption (BSFC) for all test conditions. The increase occurred at the exhaust gas temperatures (EGTs) and cylinder pressures (CPs) with hydrogen addition. The NOx and total hydrocarbon (THC) emissions decreased with the hydrogen addition until 30 lpm at 40 and 60 Nm engine loads. On the other hand, they increased at 80 Nm engine load for all hydrogen additions. While CO2 and O-2 emissions decreased with the hydrogen addition, the smoke emissions increased. It was found that the value of 30 lpm was the optimum condition of the hydrogen addition rates. (C) 2020 Elsevier Ltd. All rights reserved.Publication Metadata only The effect of hydrogen on the thermal efficiency and combustion process of the low compression ratio CI engine(PERGAMON-ELSEVIER SCIENCE LTD, 2021) YILMAZ, İLKER TURGUT; Yilmaz, Ilker TurgutIn this study, it was purposed to investigate the hydrogen enrichment effect on combustion characteristics of a low compression ratio turbocharged Common-Rail CI engine. The compression ratio was lowered from 18.25 to 16.9. Tests were conducted at 40 Nm, 60 Nm, 80 Nm, 100 Nm and 120 Nm loads at a constant 1750 rpm. Compared to the test with the original compression ratio, the low compression ratio tests yielded lower maximum cylinder pressures, maximum rate of heat releases, maximum rate of pressure rises, ringing intensity. Combustion durations increased but ignition delays fluctuated with hydrogen enrichment. The cylinder pressures, the first heat release and the first pressure rise rates increased with the higher hydrogen flow rates. Besides, the second peaks of pressure rise rates and heat release rates decreased. The hydrogen enrichment firstly increased and then decreased the brake thermal efficiency of the low compression ratio engine. Ringing intensity increased with increasing engine load and hydrogen amount.Publication Metadata only Energy, Exergy and Exergo-Economic Characteristics of Hydrogen Enriched Hydrocarbon-Based Fuels in a Premixed Burner(TAYLOR & FRANCIS INC, 2021) YILMAZ, İLKER TURGUT; Ozdemir, Mehmed Rafet; Yangaz, Murat Umut; Yilmaz, Ilker TurgutThe enrichment of conventional fuels by hydrogen is quite popular owing to positive environmental aspects compared to the main fuel. In most of the studies, the entropy analysis was not examined in detail. In this research, exergy (second law) analysis of hydrogen-enriched methane, natural gas, propane, LPG, and biogas were analyzed using the numerical model in a premixed burner due to their wide usage in the industry as well as in the household appliances. In the numerical model, the discrete ordinates radiation and Realizable k- epsilon turbulence models were coupled with the premixed combustion model. The rate of increase for hydrogen of each fuel is considered as 10%. The premixed burner exhibited better performance in terms of energy and exergy with the rise of hydrogen enrichment. The most improvement was observed at biogas tests. The results showed that the chemical composition of the base fuel is a significant parameter that affects the exergy and energy capability of the burner due to chain reactions of radicals in the base fuel with hydrogen. It can be concluded that the hydrogen enrichment of biogas in premixed burners is promising in comparison with other tested fuels from both energy and exergy perspective.Publication Metadata only Use of hydrogen-biogas mixture as fuel in common-rail dieselengine with thermal barrier coating(2022-10-07) YILMAZ, İLKER TURGUT; GÜMÜŞ, METİN; ŞANLI A., YILMAZ İ. T. , AKÇAY M., GÜMÜŞ M.Publication Metadata only Investigation of combustion and emission characteristics in a TBC diesel engine fuelled with CH4-CO2-H-2 mixtures(PERGAMON-ELSEVIER SCIENCE LTD, 2021) YILMAZ, İLKER TURGUT; Sanli, Ali; Yilmaz, Ilker Turgut; Gumus, MetinIn this study, an experimental investigation was performed to reveal combustion and emission characteristics of common-rail four-cylinder diesel engine run with CH4, CO2 and H-2 mixtures. The engine pistons were thermally coated with zirconia and Ni-Al bond coat by plasma spray method. With a small amount of the pilot diesel, port fuelled methane (100% CH4), synthetic biogas (80% CH4 + 20% CO2), and hydrogen presented (80% CH4+10% CO2+10% H-2) mixtures were used as main fuel at different loads (50 Nm, 75 Nm, and 100 Nm) at a constant speed of 1750 min(-1). Comparative analysis of the combustion (cylinder pressure, PRR, HRR, CHR, ringing intensity, CA10, CA50, and CA90), BSFC, and emissions (CO2, HC, NOx, smoke, and oxygen) at the various engine loads with and without piston coating was made for all fuel combinations. It was found that coating the engine pistons enhanced the examining combustion characteristics, whereas it slightly changed BSFC and most of the emissions. As compared to the sole diesel fuel, the gaseous fuel operations showed higher in-cylinder pressure, PRR, and ringing intensity values, earlier combustion starting and CAs, and lower diesel injection pressure at the same engine operating conditions. Dramatic increase in the ringing intensity was particularly found by the hydrogen introduced mixture under the tests with coated piston. HC and CO2 emissions increased in operation with the synthetic biogas; however, hydrogen introduction reduced HC emissions by 4.97-30.92%, and CO2 emissions by 5.16-10%. (C) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.Publication Metadata only Evaluation of combustion characteristics in a common rail diesel enginefueled butanol/nheptane/diesel blends(2022-04-09) SAYIN, CENK; VARGÜN, MUSTAFA; YILMAZ, İLKER TURGUT; VARGÜN M., Yapmaz A., YILMAZ İ. T., SAYIN C.Publication Metadata only Effects of hydrogen enrichment on combustion characteristics of a CI engine(PERGAMON-ELSEVIER SCIENCE LTD, 2017) DEMİR, ABDULLAH; Yilmaz, I. T.; Demir, A.; Gumus, M.In this study a comprehensive investigation of combustion (cylinder pressure, rate of pressure rise, ignition delay) and heat release (rate of heat release, cumulative heat release and center of heat release) parameters of a four cylinder, turbocharged, common rail compression ignition engine running with hydrogen addition was carried out. Hydrogen was send into intake manifold by using a mixing chamber. Flow rates of hydrogen were 20 lpm and 40 lpm for achieving constant speed of 1750 rpm at 50 Nm, 75 Nm and 100 Nm engine loads (EL). Results showed that maximum cylinder pressures (CPs), rate of pressure rises (ROPRs) and ignition delays (IDs) raised, rate of heat releases (ROHRs) decreased and combustion durations (CDs) extended with hydrogen addition. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.