Laminar burning velocities of hydrogen-air and methane-air flames from ambient to cryogenic temperatures at different equivalence ratios

This study aims to provide laminar burning velocity measurements of lean, stoichiometric, and rich H₂-air and CH₄-air flames at cryogenic temperatures, as well as to determine the accuracy of the existing high-temperature modeling approach (i.e., empirical and kinetic models) to simulate them. The lowest temperatures reached experimentally are 100–120 K and 150–160 K (depending on the equivalence ratio) for H₂-air and CH₄-air mixtures, respectively. Simulations are conducted with Cantera down to 100 K in all conditions with several kinetic models. This study summarizes both critical aspects of the experimental procedures by comparing the present results with previous data and important numerical considerations by evidencing sensitive simulation parameters and addressing the 200 K temperature limit of Cantera's solver. Quantitative analyses revealed that both empirical power laws and kinetic models extrapolations are accurately predicting, within the experimental uncertainties, the laminar burning velocities of H₂-air and CH₄-air flames in almost all conditions.