Flame Speeds and Combustion Characteristics of Undiluted and Nitrogen-Diluted Hydrogen-Nitrous Oxide Mixtures

摘要

In the present study, some explosive properties of undiluted and nitrogen diluted H_2-N_2O mixtures were characterized. Laminar flame speeds and the explosion-induced pressure rises were determined experimentally for a range of mixture equivalence ratios (Φ ＝ 0.15-1.0), dilutions (0-55% N_2), and initial pressures (20-80 kPa). The measured flame speeds were used to validate laminar flame speed computations using a detailed chemical kinetic mechanism. The results demonstrate that hydrogen-nitrous oxide mixtures exhibit laminar flame speeds as large as 350 cm/s and pressure rise coefficients (K_g) as large as 35 MPa m/s. Also, flames in lean mixtures are shown to be highly unstable which can lead to flame acceleration and possible deflagration-to-detonation transition.