Chapter 10: Spatially Resolved Detonation Pressure Data From Rate Sticks

Quantifying how, and if, the pressure varies across a propagating detonation wave front is a parameter of interest. To investigate this phenomenon three 30 mm diameter rate stick experiments were performed. These used a TATBbased explosive with a density of 1.903 ± 0.003 g cm-3. Rate sticks measure the velocity of detonation (VoD) and detonation wave shape of an explosive in the same experiment, typically using time of arrival diagnostics and a streak camera. In this work instead of using a streak camera to interrogate the shape of the detonation wave as it breaks out from the end of the cylinder, an array of 15 Heterodyne velocimetry (HetV) probes was fielded. Although HetV probes have lower spatiotemporal resolution than a streak camera, this setup meant it was possible to determine the VoD, wave shape and pressure in the same experiment. The pressure was inferred from the velocity measurements made by each of the probes through a Kel-F 800 window. The probe jump-off times were combined with the VoD, measured using electrical time of arrival diagnostics, to determine the wave shape. The data from these rate sticks will be presented and comparisons made to previous datasets.