Two-dimensional computations of the propagating detonations in a stoichiometric hydrogen-oxygen diluted with nitrogen or argon mixture (2H2+O2+3.76N2/3.76Ar) were performed using a detailed chemical reaction mechanism. The transverse wave strength was defined as the dimensionless pressure increase across the reflect shock and was determined for the different channel widths at initial pressures 1.000, 0.421, and 0.132 atm. The shock structure of the detonation propagating through a narrow channel evolved just from a single Mach structure to a double Mach structure. Unreacted pockets were cut off by the transverse wave collisions, but they immediately burned. When a detonation propagated through a wide channel, the shock structure evolved continuously from a single Mach structure to a complex Mach structure, except for the hydrogen-oxygen mixture diluted with argon at 0.132 atm. The channel width, WMAX, was the widest one in which a single transverse wave appeared, and showed good agreement with the cell width of the previous experimental cell widths. In the hydrogen-air mixture at initial pressure 1.000 and 0.421 atm, the transverse wave strength increased up to 1.50 with increasing the channel width, and the strong transverse detonation occurred. There was a close relation between the second explosion limit and the occurrence of the strong transverse detonation observed in hydrogen-air mixture at 1.000 and 0.421 atm. Since the frontal shock oscillated, the post-shock condition varied across the second explosion limit. Steep increasing of the induction length might cause the onset of the strong transverse detonation. We suggested that the irregularity of the H2-Air detonation was connected with the occurrence of the strong transverse detonations.
|Number of pages||7|
|Journal||Kayaku Gakkaishi/Journal of the Japan Explosives Society|
|Publication status||Published - 2001 Nov|
ASJC Scopus subject areas
- Geotechnical Engineering and Engineering Geology
- Building and Construction