Skeletal and Compact Validated Mechanisms for Iso-dodecane Using a Decoupling Methodology

Abstract

Iso-dodecane is an important component in developing surrogate fuel mixtures for conventional and alternative jet fuels. Despite some progress in recent years, there is still a requirement for a compact mechanism that is well validated in both low and high temperatures when compared to the experimental data. This paper develops a new compact mechanism with the aid of a decoupling methodology for iso-dodecane validated against available experimental data over a wide range of pressures and equivalence ratios. The ignition delay results show excellent agreement over a wide range of temperatures from 600 to 1300 K that covers low and high limits compared to the empirical data at 15, 20, and 40 bar and at lean, stoichiometric, and rich conditions. The maximum discrepancy between the simulations and the experiments by a factor of 1.7 was observed for 750 K at the rich condition at 15 bar. Laminar burning velocity simulations at two different pressures were conducted for iso-dodecane, and the results were compared with the available experimental data for alcohol-to-jet (ATJ) fuel, which is mostly composed of iso-dodecane. It was found that there was very good agreement between the modeling results and the experimental data. The final version of the new mechanism includes 158 species and 986 reactions and has potential in further functional kinetic investigations and to use for complex geometries of combustion systems such as Equivalent Reactor Network analyses.

Development of a surrogate and its comprehensive compact chemical kinetic mechanism for the combustion of Alcohol-To-Jet fuel

“…As it is illustrated in Fig. 3, similar to the experimental profile of iso-dodecane [24], its consumption begins around 950 K, and continues to decay until around 1200 K where it is completely consumed, although there may be some subtle differences to the experiment in that experimentally it starts to decay at slightly lower temperature and not be completely consumed until slightly higher temperature. Subsequently, the consumption of IC12 which is mainly responsible for the consumption of ATJ fuel leads to the production of the hydrocarbon intermediates over that temperature range, which in turn react to produce CO and then CO 2 .…”

“…The production of cyclic ether and the concerted elimination reaction are the important side reaction channels which have a contribution to the consumption of QOOH and RO2 radicals. Similar to the iso-dodecane pathways at low temperature [24], the NTC behaviour of ATJ fuel arises due to a competition between the degenerate chain branching reactions and these side reactions. As can be seen from Fig.…”

“…The validation of the sub-mechanisms have been discussed in our previous works [24,25]. Indeed, the initial raw sub-mechanisms were extracted from a detailed mechanism in the literature [26] and revised by adding some missing reactions of iso-paraffin kinetic models, and by modifying some reaction rates.…”

“…Indeed, the initial raw sub-mechanisms were extracted from a detailed mechanism in the literature [26] and revised by adding some missing reactions of iso-paraffin kinetic models, and by modifying some reaction rates. The details of the revisions can be found in the published works [24,25].…”

Reduced Reaction Mechanisms for Sustainable Aviation Fuel (SAF): Isoparaffinic Alcohol-to-Jet Synthetic Paraffinic Kerosene (AtJ-SPK) and Its Blends with Jet A

“…The difference compared with DRGEP is that it defines the directed graph and measures the species’ importance through considering both the production and consumption fluxes. This method has also been successfully employed for mechanism reduction in many previous studies. , FSSA is more effective in analyzing the species importance in the whole reaction kinetics, but it is very time-consuming. Therefore, it is used in the final stage when the numbers of species and reactions are relatively smaller after the reductions using the DRGEP and DRGPFA methods.…”