High-pressure shock tube experiments and modeling of n-dodecane/air ignition

We have measured ignition delay times of n-dodecane/air mixtures over a range of conditions including pressures of 18-31 atm, temperatures of 943-1177 K, and equivalence ratios (phi) of 0.5-1.0, utilizing the heated, high pressure shock tube (HPST) at Stanford University. The shock tube and mixing assembly were heated to 120 and 170 C, respectively, to prevent condensation of n-dodecane fuel (because of its low vapor pressure). Ignition delay times behind reflected shocks were measured using side-wall pressure and OH* emission diagnostics. Shock tube ignition time measurements can provide excellent validation targets for refinement of jet fuel kinetic modeling, and n-dodecane is widely used as the principal representative for n-alkanes in jet fuel surrogates. To the best of our knowledge, we report the first gas-phase shock tube ignition time data for n-dodecane. We also provide comparisons with the ignition delay time predictions of two detailed JP-8 mechanisms that include n-dodecane as an important JP-8 surrogate component.