STROJARSTVO, cilt.52, sa.5, ss.559-567, 2010 (SCI-Expanded)
In this study, numerical simulations of combustion characteristics using pure methane and 70 % CH(4)-30 % H(2) blends were investigated in a spark ignition engine. The numerical calculations were performed using the finite volume CFD code FLUENT with standard k-epsilon model using the compression ratio and the engine speed are 10 and 2000 rpm respectively. Excess air ratios were selected as 1, 1.2 and 1.4. The spark timings were started at 45, 30 and 15 degree crank angle (CA) before top dead center (BTDC). The results of the combustion process were investigated as a function of crank angle. The maximum cylinder pressures and temperatures were obtained with 70 % CH(4)-30 % H(2) mixture. It is observed that peak pressure values are decreased when the excess air ratio increased.