دانشگاه خواجه نصیرالدین طوسی
عنوان مقاله [English]
Reactivity Controlled Compression Ignition engines are today considered as a subdivision of HCCI engines which can control and manage the combustion process and emission production with using two different types of fuels. Combustion process in these types of engines is initiated by varying the amount of different fuels consequently, varying the reactivity of fuel in various speeds and loads. For this reason, the mixing ratio of the fuels is of great importance. Altering the fuel reactivity also affects the production of emissions. In these engines, fuel with lower reactivity is injected into intake manifold and fuel with higher reactivity is injected directly into the combustion chamber. The port injected less reactive fuel is used to achieve higher efficiency and better combustion in higher compression ratios while the fuel with higher reactivity is used to control the chemical reactions rate as well as to decrease the amount of produced nitrogen oxides and soot. In this work, previously developed chemical mechanisms for N-Heptane and Iso-Octane are used to simulate chemical reaction rates. Iso-Octane has been used to represent the fuel with lower reactivity while N-Heptane has been used as the fuel with higher reactivity. In the first step, the effects of Iso-Octane and N-Heptane existence are discussed and then important combustion parameters such as emission, knock and incomplete combustion are investigated in case of changing the both fuels ratios.