Detonation Propagation Through Ducts in a Pulsed Detonation Engine

Abstract

A study of configurations to allow a consistent and predictable transition of a detonation from one detonation tube to another is presented. Development of a continuously operating pulsed detonation engine (PDE) without a high energy ignition system or a deflagration-todetonation transition (DDT) device will increase engine efficiency, reduce cost, improve performance, and reduce weight. The intent of this study was to minimize energy losses of a detonation wave in order to directly initiate another detonation wave. Detonation tube fill fraction, purge fraction, equivalence ratio, cross-over length and cross-over geometry were varied to determine their effect on direct initiation via a cross-over tube. Velocities at or above the upper Chapman-Jouguet (C-J) velocity point are desired and considered successful detonations. It was found that a cross-over tube with a “U” shaped geometry and a width at least 75% of the initiated tube’s width provided the best conditions for direct initiation.