Detonation characteristics of hydrogen-oxygen mixtures

Abstract

Detonation velocities were measured in mixtures of hydrogen and oxygen containing 25 to 75 mole % hydrogen at initial temperatures from 160° to 580°K. and initial pressures from 1/2 to 2 atm. The measurements were made in a number of tubes of different diameter to permit extrapolation to a tube of infinite diameter. Theoretical detonation characteristics were computed for the same range of conditions. The measured and computed velocities are in good agreement except in rich mixtures and at subatmospheric pressures. Schlieren photographs reveal that the detonation wave front is very thin for a stoichiometric mixture but degenerates to a complicated zone of interacting shock waves and turbulent combustion as the percentage of hydrogen is reduced. The detonation velocity is found to depend only slightly on initial temperature and pressure. The computed pressures behind the detonation and reflected waves are roughly proportional to initial pressure and to the reciprocal of the initial temperature.