Microwave velocity measurements of marginal detonation waves

Abstract

A prerequisite to a study of a detonation wave structure is the establishment of an equilibrium frontal configuration, which is repeatable at equi-spaced distances along the detonation tube, together with a constant average wave velocity. A microwave interferometer is described which is capable of giving a continuous monitor of the velocity of a marginal planar detonation wave propagating in a narrow rectangular channel of transverse dimensions 3×¼ inch and 6 metres long. One important conclusion of this work is that some marginally propagating waves may appear to acquire a sensibly constant velocity, near the C-J value, over a distance of 1-2 m before a rapid decay in velocity occurs. This observation emphasizes the need for continuous velocity measurement in all waves near the limit.