نویسندگان
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
The main purpose of this paper is the development of a multi-zone model for the prediction of combustion, performance and emissions characteristics of HCCI engines. The developed model contained four various zones that included the core zone, the boundary layer zone, outer zones, which were between the core and the boundary layer, and the crevice zone. The core zone was the innermost zone and the boundary layer was the nearest zone to the wall. The volume of the crevice zone was constant and equaled to 3% of the volume of TDC, but the volume of other zones changed by the time. There was the conductive heat transfer between neighborhood zones. The mass transfer was considered between zones, too. There was the convective heat transfer between boundary layer gases and combustion chamber walls. Suitable chemical kinetics mechanisms were used for the accurate combustion simulation. To calculate the in-cylinder temperature, the pressure and the composition at intake valve closing, a single-zone model was used for the simulation of the gas exchange process. The model was validated using experimental data of the HCCI combustion of n-heptane and methane fuels. Results showed that the model can predict HCCI combustion, performance and emissions characteristics, accurately. The maximum error of model results for the CO prediction was equal to 1.7% and for the UHC prediction was equal to 12.86%.
کلیدواژهها [English]
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