Laser Speciation of Product Gases During Ammonia and Hydrogen Combustion Inside a Shock Tube

This study presents experimental shock tube laser absorption spectroscopy data to validate high-pressure and high-temperature chemical kinetic mechanisms for mixtures of H2/air, NH3/air, and H2/CO/NO2/air diluted in argon (95-98%) at high pressures (5, 10, 25 bar) and high temperatures (1000 to 2150 K). The mixtures were at equivalence ratios of 0.5, 1.0, and 1.5 to cover the range of possible conditions experienced throughout practical combustors. Laser absorption spectroscopy data was measured for NH3, H2O, CO, and NO using a novel multi-species setup. Chemical kinetic mechanisms contain the fundamental chemistry used in reactive computational fluid dynamic (CFD) modeling of propulsion systems. Validation of these mechanisms through fundamental combustion chemistry experiments is essential to ensure the accuracy and efficiency of CFD simulations. The current chemical kinetic mechanisms regarding the combustion of H2, NH3, and syngas have not been extensively validated at the high-temperature and high-pressure conditions commonly experienced in combustors. Thus, speciation data was collected on the consumption of NH3 and formation of H2O for the NH3/air mixtures, the formation of H2O for the H2/air mixtures, and the formation of H2O and NO and consumption of CO for the H2/CO/NO2/air mixtures. This study provides data for mechanism validation through the collection of experimental shock tube laser absorption spectroscopy data.