Abstract
The combustion and ignition characteristics of three fuels with different reactivities have been investigated by a reduced chemical kinetic model. In the present work, the chemical kinetics of conventional single fuel and binary fuel, relevant to gas-turbine engines, are extended and attempted to explore in the tri-fuel (TF) context, with the help of TF blends of LPG + CH4+H2 at the pressure and temperature range of 1-20 atm and 900-2000 K, respectively. The blending of hydrogen with hydrocarbon fuels improves flame propagation, reduces emissions, and increases the combustion performance of the engine. A detailed study is conducted to explore the characteristics of TF mixture over a wide range of operating conditions by considering eight different test mixtures (M1-M8). The test mixtures (M2 to M4) contain higher hydrogen content and thus hydrogen kinetics will tend to dominate, while test mixtures (M6 to M8) contain a higher concentration of hydrocarbons, thus the methyl radical chemistry plays a prominent role in the oxidation process. Such contrasting trends were further explored by extensive chemical kinetic modeling with the help of the reduced USC Mech_50 species model from our previous work [1] to analyze the ignition delay time, laminar flame speed, flame temperature, and heat release rate characteristics. In addition, the reaction pathway analysis through sensitivity analysis of OH and CO radical, and flow rate sensitivity analysis has also been conducted to highlight the essential chemical reactions which play a crucial role in auto