Dual detonation régimes in hydrogen/oxygen and deuterium/oxygen mixtures

Abstract

Velocity data have been determined as a detailed function of composition for the systems: S H = 2H 2 + O 2 diluted with H 2 , O 2 or CO 2 and S D = 2D 2 + O 2 diluted with D 2 or O 2 . Detonation limits have been established. Each mixture received standard initiation from a detonation in {2H 2 + O 2 }. Velocities were determined 8 ft. downstream from the initiating impact. Within this distance, either a constant velocity of detonation front was reached, or the mixture under test had failed to propagate detonation. Near the limit concentrations, under certain conditions an alternative constant velocity régime established itself. These detonation velocities were still greater than the velocity of sound in the unreacted mixture but about 30% below those of the ‘normal' régime, which alone extends throughout the entire composition range between the limits. Evidence is discussed that this alternative régime is associated with a different reaction mechanism in the detonation front, with hydrogen (deuterium) peroxide as end-product. Subsequent decomposition of this hydrogen peroxide apparently leads to the formation of a second detonation wave. This follows the first with a higher velocity and eventually overtakes it, thereby setting up the normal velocity régime, for which water is the end-product. Possible factors leading to such dual detonation régimes are discussed.