Global reaction mechanism for the auto-ignition of full boiling range gasoline and kerosene fuels

Abstract

Compact reaction schemes capable of predicting auto-ignition are a prerequisite for the development of strategies to control and optimise homogeneous charge compression ignition (HCCI) engines. In particular for full boiling range fuels exhibiting two stage ignition a tremendous demand exists in the engine development community. The present paper therefore meticulously assesses a previous 7-step reaction scheme developed to predict auto-ignition for four hydrocarbon blends and proposes an important extension of the model constant optimisation procedure, allowing for the model to capture not only ignition delays, but also the evolutions of representative intermediates and heat release rates for a variety of full boiling range fuels. Additionally, an extensive validation of the later evolutions by means of various detailed n-heptane reaction mechanisms from literature has been presented; both for perfectly homogeneous, as well as nonpremixed/stratified HCCI conditions. Finally, the models potential to simulate the autoignition of various full boiling range fuels is demonstrated by means of experimental shock tube data for six strongly differing fuels, containing e.g. up to 46.7% cycloalkanes, 20% napthalenes or complex branched aromatics such as methyl-or ethylnapthalene. The good predictive capability observed for each of the validation cases as well as the successful parameterisation for each of the six fuels, indicate that the model could, in principle, be applied to any hydrocarbon fuel, providing suitable adjustments to the model parameters are carried out. Combined with the optimisation strategy presented, the model therefore constitutes a major step towards the inclusion of real fuel kinetics into full scale HCCI engine simulations.

Simplifying ignition delay prediction for homogeneous charge compression ignition engine design and control

“…The switch functions have the form h = 1=2 (1 À tanh ((T À (T cross + k))=5), where T cross corresponds to T L and T H for the first two and last two Comparison of simulated MD ignition delay times with ignition predictions using the empirical correlation proposed by Vandersickel et al 27,28 switches, respectively; k equals to 250, 25, 225 and 50 for h 1 to h 4 , respectively.…”

“…It is interesting to compare the current approach with that proposed by Vandersickel et al 27,28 in equation (7), focusing on methyl decanoate. The three subcorrelations for methyl decanoate obtained in this work are fused into a generalized correlation using equation (7).…”

“…Comparison of simulated MD ignition delay times with ignition predictions using the empirical correlation proposed by Vandersickel et al 27,28 …”

“…18 Considering the fact that most of the ignition correlations have been obtained only for high-temperature values, Hernandez et al 26 developed correlations of diesel fuel surrogates for each stage of ignition and demonstrated relationship of threshold temperatures between stages with pressure and equivalence ratio. Another generalized correlation approach is a recent empirical ignition correlation approach proposed by Vandersickel et al 27,28 It comprises separate correlations for the low-, high- and intermediate-temperature or negative temperature coefficient (NTC) regions which together can yield ignition delay predictions over the entire temperature range. This approach has recently been used by Gowdagiri and Oehlschlaeger 29 to obtain generalized ignition correlations for alternative jet fuel and diesel.…”

From fundamental study to practical application of kerosene in compression ignition engines: An experimental and modeling review

“…Table 3 shows a compilation of the latest as well as significant kerosene surrogates from the literature, the number of species and reactions in their respective reaction mechanisms, as well as the target properties that each surrogate was made to emulate. 45,51,56,68–70,82,85,154–156,158,161,163–186…”