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Öğe Numerical investigation of the effect of spray cone angle on spraydynamics of a DI diesel engine(Gazi Üniversitesi, 2019) Altun, Şehmus; Fırat, Müjdat; Varol, YasinIn this study, the effect of spray cone angle on spray dynamics of DI diesel engine equipped with common-rail fuel injection system is investigated numerically using a multidimensional Computational Fluid Dynamics (CFD) simulation tool, AVL-FIRE code. The in-cylinder spray dynamics such as spray and vapor penetration, droplet diameter, and Turbulence Kinetic Energy (TKE) as well as droplet distribution are investigated for different spray cone angles changed from 120o to 160o . The simulation results indicate that the selected spray cone angle actually changed all spray dynamics. Spray and vapor penetration and droplet diameter are affected with increasing spray cone angle. In-cylinder air motion was later studied for a number of spray cone angles, which identified a slightly changed in-cylinder Turbulence Kinetic Energy (TKE) around the compression top dead center (TDC). Additionally, it was determined that spray cone angles have considerable affects the fuel spray dynamics. Both liquid and vapor penetration are directly linked to the spray cone angleÖğe A numerical study of no and soot formation in an automotive diesel engine fueled with diesel-biodiesel blends(Uluslararası Yakıtlar, Yanma ve Yangın Dergisi, 2016-12-01) Altun, Şehmus; Fırat, Müjdat; Varol, YasinIn this paper, engine simulation results are presented to give information on the effect of diesel-biodiesel blends on combustion and emission characteristics of a multiple injection automotive diesel engine. Numerical Study was performed in Computational Fluid Dynamics (CFD) simulation software AVL-FIRE coupled to AVL-ESE Diesel. An improved version of the ECFM-3Z combustion model has been applied coupled with advanced Zeldovich and Kinetic models for NO and soot formation, respectively. The simulation results were validated against the experimental results by comparing the in-cylinder pressure and heat release rate for diesel-biodiesel blends at 2000 rpm under 100% load, and a maximum variation of 5% deviation on the peak cylinder pressure and 4% for heat release rate was found. Simulation results revealed that with the increase of biodiesel amount in the fuel, CO and soot emissions were reduced while NO increased at the simulated operating conditions. In addition, in-cylinder NO and Soot mass fractions were found to be high at 20 and 10 CA ATDC, respectively.
