Numerical Investigation of Extinction Strain Rates in Ammonia-Hydrogen Fuel Blends for Aviation Applications

This study explores how ammonia-hydrogen fuel blends behave in a counterflow diffusion flame, with a focus on extinction strain rate under high-pressure conditions relevant to aviation. Ammonia is a promising green fuel, but it burns slowly and produces high NOx emissions. Mixing it with hydrogen can help improve flame speed and stability. This investigation aims to understand how higher pressures affect flame extinction behavior in a controlled environment. Using Cantera and the Glarborg chemical mechanism, simulations were performed for a 50% NH3 – 50% H2 blend at pressures ranging from 1 to 40 bar. The extinction strain rate, which tells us how much strain the flame can take before going out, was found to increase significantly with pressure. A vertical burner setup is being developed to validate the simulation results through experiments. These results can guide the development of cleaner and more reliable combustion systems for future aviation engines using alternative fuels.