Role of atomic hydrogen diffusion in hydrogen flame inhibition

A laminar flame propagating in a rich homogeneous hydrogen-air mixture with addition of propylene is numerically simulated. Small amounts of propylene are shown to reduce the concentrations of HO2 and OH in the low-temperature zone of the flame front, which effectively reduces the laminar burning velocity. In the flame front, propylene is consumed completely with formation of CO, CO2, CH4, C2H2, H2, and H2O, whereas hydrogen undergoes little oxidation compared to propylene.