A comprehensive experimental and modeling study of n-propylcyclohexane oxidation

Abstract

n-Propylcyclohexane (nPCH) is an important surrogate component for jet fuel, gasoline, and diesel. To comprehensively understand its combustion properties and chemical kinetics, ignition delay time (IDT) measurements of nPCH/air mixtures were performed in a high-pressure shock tube (HPST) at fuel-rich conditions (φ = 2.0), pressures of 10‒40 bar and temperatures of 738‒1400 K. Also, low-temperature IDT measurements were carried out in a rapid compression machine (RCM) at a pressure of 10 bar, temperatures of 615‒750 K, and equivalence ratios of 0.5‒2.0. In addition, laminar flame speeds were measured at an initial temperature of 403 K, at pressures of 1.01 bar and 3.04 bar, and equivalence ratios ranging from 0.7 to 1.4. A detailed chemical kinetic mechanism has been developed in the current work to describe the oxidation of nPCH, including 10 high-temperature reaction classes and 24 low-to-intermediate temperature reaction classes. Important reactions were identified by sensitivity and flux analyses at different temperatures, pressures, and equivalence ratios. These reaction classes play a very important role in determining the fuel reactivity and the distribution of products. This model shows good agreement with the experiment measurements carried out in this work and the ones in the literature, including IDTs, species data from jet-stirred reactor and flow reactor experiments, and laminar flame speeds.