Unsteady self-sustained detonation waves in flake aluminum dust/air mixtures

TL;DR

This study investigates the behavior and structure of self-sustained detonation waves in flake aluminum dust/air mixtures, revealing complex wave interactions, cellular structures, and velocity variations in a large-diameter tube.

Contribution

It provides detailed experimental analysis of detonation wave structures, including spin detonation fronts and triple-point configurations, in aluminum dust/air mixtures.

Findings

Identification of two-head spin detonation fronts

Analysis of cellular structures and triple-point interactions

Measurement of velocity and overpressure variations

Abstract

Self-sustained detonation waves in flake aluminum dust/air mixtures have been studied in a tube of diameter 199 mm and length 32.4 m. A pressure sensor array of 32 sensors mounted around certain circumferences of the tube was used to measure the shape of the detonation front in the circumferential direction and pressure histories of the detonation wave. A two-head spin detonation wave front was observed for the aluminum dust/air mixtures, and the cellular structure resulting from the spinning movement of the triple point was analyzed. The variations in velocity and overpressure of the detonation wave with propagation distance in a cell were studied. The interactions of waves in triple-point configurations were analyzed and the flow-field parameters were calculated. Three types of triple-point configuration exist in the wave front of the detonation wave of an aluminum dust/air mixture. Both strong and weak transverse waves exist in the unstable self-sustained detonation wave.