n -Hexane Flame Propagation at Elevated Temperatures and Pressures in a Shock Tube

Owing to its flammability and high vapor pressure for a long-chain hydrocarbon, n-hexane is a valuable component in surrogate mixtures for commodity fuels and proxy fuel for fire safety testing in aircraft certification. Despite n-hexane’s utility, experimental measurements of key combustion properties at high temperatures and pressures relevant to engine environments are lacking. In this work, we experimentally characterized n-hexane flame propagation using the Imaging Shock Tube (IST) facility at Stanford University. Laminar flame speeds of n-hexane mixtures with lean, stoichiometric, and rich equivalence ratios (�� = 0.6, 1.0, and 1.5) were measured in the 600–1000 K temperature range at pressures between 1–5 atm. For the first time in this temperature and pressure regime, experimental data was directly compared against flame speed predictions from simulations using the NUIGMech 1.1 and Lawrence Livermore National Laboratory chemical kinetics models. This research provides novel data at previously inaccessible conditions for developing and improving chemical kinetics models for n-hexane and larger alkane oxidation. By extension, this work also supports advances in computational reacting flow modeling for propulsion system design.