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The new EDC model formulation based on the operator-splitting procedure applied to the mass conservation equations for species participating in reversible chemical reactions which can be interpreted as representing combustion in a partially stirred reactor (PaSR) volume is presented. The model has been implemented in the KIVA-3V code, and examples of the model application to spray and gas combustion are illustrated, first, by the results of the 3-D modeling of the Diesel DI Volvo D12C engine. The combustion mechanism of diesel oil surrogate included of 68 species (including soot aromatic precursors) participating in 280 reversible reactions. Mean features of diesel spray engine combustion under conditions of delayed injection when auto-ignition has much in common with HCCI process are predicted in accordance with experimental data.

To reproduce the Diesel fuel structural effect on soot formation, the diesel oil surrogate chemical model has been developed, validated using constant volume and applied to 3-D engine calculations using the KIVA-3V code. To better predict soot production, the presence of toluene, A1CH3, which is a product of benzene alkylation, in the reaction mechanism of n-heptane oxidation has been assumed. Soot formation as a solid phase has been simulated via a finite-rate transition of the gaseous precursor of soot, A2R5, to graphite. The final mechanism consists of 68 species and 278 reactions. Reasonable agreement of predictions with constant volume experimental data, on ignition delay times, flame appearance, accumulated amount of soot produced and soot cloud evolution has been achieved. Then, the fuel surrogate model has been applied to 3-D simulation (on a sectored mesh) of the Volvo NED5 DI Diesel engine.

It has been found in the experiments [1], that fuel injection timings, ignition delays, and, thus, the mixture composition at the moment of auto-ignition had a considerable impact on soot formation in a constant volume at Diesel-like conditions. At increased ambient temperatures, soot formation started earlier and higher soot mass concentrations were registered during combustion. Increasing air pressures lead to a slight increase of the mass of soot formed. Nearly no difference of the maximum soot mass concentration has been observed, albeit the time period, in which soot was detected at a certain position increases with the ambient pressure increase. As observed in more resent experiments [2], a variation of the injected fuel quantity has been in an evident fashion related with the amount of soot produced with an exception that less soot yield has been confirmed when the injection time was simultaneously reduced.