Combustion kinetic modeling using multispecies time histories in shock-tube oxidation of heptane

摘要

Recently, species time histories have been measured during n-heptane oxidation behind reflected shock waves [D.F. Davidson, Z. Hong, G.L. Pilla, A. Farooq, R.D. Cook, R.K. Hanson, Combust. Flame 157 (2010) 1899-1905]. The highly precise nature of these measurements is expected to impose critical constraints on chemical kinetic models of hydrocarbon combustion. In this paper, we apply the Method of Uncertainty Analysis using Polynomial Chaos Expansions (MUM-PCE) [D.A. Sheen, X. You, H. Wang, T. Lovas, Proc. Combust. Inst. 32 (2009) 535-542] to demonstrate how the multispecies measurement may be utilized beyond simple model validation. The results show that while an as-compiled, prior reaction model of n-alkane combustion can be accurate in its prediction of the detailed species profiles, the kinetic parameter uncertainty in the model remains to be too large to obtain a precise prediction of the data. Constraining the prior model against the species time histories within the measurement uncertainties led to notable improvements in the precision of model predictions against the species data as well as the global combustion properties considered. Lastly, we show that while the capability of the multispecies measurement presents a step-change in our precise knowledge of the chemical processes in hydrocarbon combustion, accurate data of global combustion properties are still necessary to predict fuel combustion.