In order to investigate the factors contributing to detonation failure, the velocity-composition relationships of the following gaseous mixtures near the limiting concentrations were investigated in a one inch diameter cylindrical tube: System SH = 2H2 + 02 separately diluted with H2, 02, He, A, CO2 and• NH3; System SD = 2D2 + 02 diluted with D2, 02, He and A; and System Sc = C2N2 + 02 diluted with C2N2, 02, He and A. In all cases, detonations were initiated by passing a detonation in a stoichiometric (2:1) hydrogen-oxygen mixture into the test mixture. Velocities were determined by measuring the time taken for the detonation front to pass between successive detection stations, a known distance apart. In additions several hitherto unobserved phenomena were noted: (i) Mixtures diluted with argon showed considerably wider detonation limits than when diluted with helium despite the fact that they should be hydrodynamically similar. In the same way, mixtures containing hydrogen showed wider detonation limits than corresponding mixtures containing deuterium. These mass effects could only be partly explained by existing theories for detonation failure. Other explanations are examined. (ii) Reproducible fluctuations in the detonation velocity-composition relationships were found near the limiting concentrations. These were found to be substantially due to a spin head following the same path down the detonation tube on successive occasions, thereby causing a displacement in the measured time intervals. (iii) In some mixtures containing hydrogen or deuterium, a second, lower velocity regime was found to co-exist with the "normal" detonation velocity regime which alone prevailed throughout the entire composition range. The measured velocities in the lower velocity regime were generally about 30% lower than in the "normal" regime. There were strong indications that this was due to the formation of hydrogen (deuterium) peroxide in the detonation front. Possible explanations for, and implications of, these novel phenomena are discussed.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:622994 |
| Date | January 1967 |
| Creators | Wood, Ian Frederick |
| Publisher | Imperial College London |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/10044/1/17643 |
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