A Study of Detonation Propagation and Diffraction with Compliant Confinement
A previous computational study of diffracting detonations with the ignition-and-growth model demonstrated that contrary to experimental observations, the computed solution did not exhibit dead zones. For a rigidly confined explosive it was found that while diffraction past a sharp corner did lead to a temporary separation of the lead shock from the reaction zone, the detonation re-established itself in due course and no pockets of unreacted material were left behind. The present investigation continues to focus on the potential for detonation failure within the ignition-and-growth (IG) model, but now for a compliant confinement of the explosive. The aim of the present paper is two fold. First, in order to compute solutions of the governing equations for multi-material reactive flow, a numerical method of solution is developed and discussed. The method is a Godunov-type, fractional-step scheme which incorporates an energy correction to suppress numerical oscillations that would occur near the material interface separating the reactive material and the inert confiner for standard conservative schemes. The numerical method uses adaptive mesh refinement (AMR) on overlapping grids, and the accuracy of solutions is well tested using a two-dimensional rate-stick problem for both strong and weak inert confinements. The second aim of the paper is to extend the previous computational study of the IG model by considering two related problems. In the first problem, the corner-turning configuration is re-examined, and it is shown that in the matter of detonation failure, the absence of rigid confinement does not affect the outcome in a material way; sustained dead zones continue to elude the model. In the second problem, detonations propagating down a compliantly confined pencil-shaped configuration are computed for a variety of cone angles of the tapered section. It is found, in accord with experimental observation, that if the cone angle is small enough, the detonation fails prior to reaching the cone tip. For both the corner-turning and the pencil-shaped configurations, mechanisms underlying the behavior of the computed solutions are identified. It is concluded that disagreement between computation and experiment in the corner-turning case lies in the absence, in the model, of a mechanism that allows the explosive to undergo desensitization when subjected to a weak shock.
- Research Organization:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 941386
- Report Number(s):
- UCRL-JRNL-233735; TRN: US200824%%576
- Journal Information:
- Combustion Theory and Modelling, Vol. 12, Issue 4; ISSN 1364-7830
- Country of Publication:
- United States
- Language:
- English
Similar Records
LX-17 Corner-Turning and Reactive Flow Failure
Reactive Flow Modeling of the Interaction of TATB Detonation Waves with Inert Materials