Detonation Cell Width Measurements for H₂–N₂O–N₂–O₂–CH₄ –NH₃ Mixtures

Abstract

Detonations of mixtures containing hydrogen and nitrous oxide were investigated in the GALCIT detonation tube (280 mm diameter, 7.3 m long). The facility and previous related studies are described in Akbar et al. (1997). We measured the detonation cell width, velocity and pressure for a range of equivalence ratios in three mixtures: 1) hydrogen-nitrous oxide; 2) hydrogen-nitrous oxide with 30% nitrogen dilution; 3) hydrogen-nitrous oxide with 30% nitrogen dilution further diluted 50% by air. In addition, we investigated the influence of adding 3% methane or 3% ammonia on the detonation behavior to hydrogen-nitrous oxide mixtures. Tests were conducted at initial pressures and temperatures of 70.9 kPa and 295 K, respectively. One-dimensional, steady, (ZND model) reaction zone calculations were performed with the modified Miller and Bowman hydrogen-nitrous oxide-methane-ammonia-oxygen-nitrogen mechanism (Akbar et al. 1997). These calculations were used to correlate and extrapolate the measured cell widths and also to determine the effect of initial conditions on the cell width.