The Gasoline-ethanol_4comp_179sp__knocking__soot-pseudo-gas.cks chemistry set consists of a 179-species gas-phase mechanism. The focus of this chemistry set is on accurate low-temperature ignition to capture knocking in SI engines and ignition in HCCI engines, along with accurate soot modeling, with soot treated as a pseudo-gas.
It represents gasoline-ethanol with the 4-component n-heptane / iso-octane / toluene/ethanol as the fuel surrogate. The mechanism captures the pathways necessary for both low- and high-temperature reactions. Since this mechanism includes low-temperature reaction pathways, it can be used for predicting knocking.
The mechanism has been validated against fundamental data for the following conditions:
Equivalence ratios of 0.4-3. This range is to capture both GDI and port-fuel injection engine local environments.
Octane numbers of ~85-100. The composition used for mechanism reduction had a composition of 39/30/21/10 wt% toluene/iso-octane/n-heptane/ethanol. n-Heptane and iso-octane compositions can be modified to change the octane number within the range listed above.
This mechanism has been reduced from a larger gasoline kinetics mechanism consisting of ~2600 species, which has been thoroughly validated against fundamental experimental data for the operating conditions of interest in engines, under the Model Fuels Consortium [20]. The Ansys Model Fuel Library (MFL) Manual includes the mechanism validation plots. The mechanism was reduced from this comprehensive "full" mechanism using the Reaction Workbench software [31], for the conditions listed above.
For the emissions, the following species predictions are expected to be accurately predicted:
The species names in the chemistry file for the fuel species are: