3D Simulation Considering Detailed Chemical Kinetics for a Homogeneous Charge Compression Ignition Engine Fueled with Methane and Dimethyl Ether

Homogeneous Charge Compression Ignition (HCCI) engines are known as a new generation of internal combustion engines. They deliver efficiencies and powers in the range of diesel engines and have achieved better fuel economy and lower NOx emission. Considering the importance of this combustion method, first the 3-D CFD model, coupled with detailed chemical kinetics, was validated with experimental results in the close part of the cycle. The results show good agreement with approximately 5% error in estimating the peak pressure. The model was investigated in different initial pressures and equivalence ratios. Results show that SOC is delayed by decreasing the inlet pressure and increasing the equivalence ratio. Dimethyl ether (DME) was used as the second fuel to reduce the knocking in case of pure methane. This work was done in the constant equivalence ratio that resulted good performance. Also, hydroxyl radical (OH*) was introduced as the controlling species and the increase of OH* had a good agreement with the heat release rate in both cases of pure and blended methane.