Experimentation and direct numerical simulation of self-similar convergent detonation wave

CEA, DAM, DIF, 91267 Arpajon, France

^a e-mail: remy.sorin@cea.fr

Abstract

The propagation of self similar convergent detonation wave in TATB-based explosive composition was studied both experimentally and numerically. The device constists in a 50 mm cylinder of TATB surrounded by an HMX tube. The detonation in HMX overdrives the detonation in TATB which adapts to the propagation velocity with a convergent front at centerline. We measured a curvature of κ = −21.2 m⁻¹ for propagation velocity of 8750 m/s, which extends the knowledge of the (D_n,κ) law. A wide ranged EOS/reaction rate model inspired from previous work of Wescott et al. was calibrated to reproduce both the run-to-detonation distance and the newly extended (D_n,κ) law for the 1D sligthly curved detonation theory. 2D Direct Numerical Simulations (DNS) were made on fine resolved mesh grid for the experimental configuration and for various driver velocities. The simulation reproduces the experimental data both qualitatively (overall detonation structure) and quantitatively (κ = −25.4 m⁻¹).