DETONATION PROPERTIES OF DENSE METHANE-OXYGEN-DILUENT GASEOUS-MIXTURES - APPLICATION TO RAM ACCELERATORS

Using a 90mm-bore, 3.15 m long detonation tube, experimental detonatio n characteristics (detonability limits, detonation velocities and peak pressures) of stoichiometric methane-oxygen-diluent mixtures at an in itial pressure up to 3.5 MPa have been experimentally investigated. A parametric study has been carried out as a function of both amount and nature of diluent, namely carbon dioxide, nitrogen and helium. The ex perimental results allowed the adjustment and validation of computatio ns of the Chapman-Jouguet characteristics by means of a thermochemical code. These experimental data associated with validated computations provide a valuable tool, among others, for the choice of the most appr opriate mixture composition in the superdetonative combustion mode for ram accelerator (ramac) experiments. The investigations were organize d to determine the upper detonable areas of dense ternary mixtures: an d to provide detonation velocity data in order to adjust a series of I ntermolecular parameters involved in the thermochemical code.