Multizones Modeling of the Combustion Characteristics of Oxygenated Fuels in CI Engines 2006-01-0051

There exist a temperature difference inside the burned gas region of the internal combustion engines due to the recompression effect inside the burned gas region. Zero-dimensional multizone model developed at Oxford Engine Research Group is implemented to investigate the generation of the temperature difference inside the burned gas region and qualitatively model the combustion characteristics within compression ignition (CI) engines. Oxygenated fuels: methanol and dimethyl ether (DME), are studied and compared with diesel. Optimum number of zones is identified for the simulation. Results for the variation in the burned gas temperature and NOx formation within the different zones of the ten-zones model and compared with the single zone. Single zone model is found to give under-prediction in burned gas temperature as well as NOx for all the three fuels. Diesel has the highest burned gas temperature and DME has burned gas temperature similar to the diesel but methanol has lower burned gas temperature. The ten-zones model shows the generation of the temperature difference within the burned gas region. Diesel is found to have the highest NOx formation than DME and methanol. Effect of heat transfer and exhaust gas recirculation (EGR) on the combustion characteristics are simulated.