Youngjin JUN, Seong-Kyun IM
DOI Number: N/A
Conference number: HiSST-2025-138
The reliable operation of scramjet combustors is hindered by two major challenges: achieving ignition within sub-millisecond residence times and mitigating severe thermal loads on combustor walls. Regenerative cooling with hydrocarbon fuels offers a promising solution, as endothermic thermal cracking simultaneously enhances heat-sink capacity and generates reactive intermediates that promote ignition. Among candidate surrogates, n-dodecane is widely used due to its representative paraffin chemistry and well-characterized thermophysical properties. However, existing detailed mechanisms are too complex for computational fluid dynamics, while no dedicated simplified reaction model for n-dodecane has been available. This study develops a two-step global reaction model for n-dodecane-air combustion tailored to scramjet-relevant conditions. The rate parameters are optimized
against ignition delay time and laminar flame speed obtained from a reference detailed mechanism. A coarse-to-fine search combined with a sequential filtering framework identified robust parameter sets, ensuring a reasonable accuracy across a broad range of pressure, temperature, and equivalence ratio. Despite the model shows modest deviations under certain conditions, it offers sufficient accuracy for preliminary simulation studies while preserving computational efficiency.