Effect of a collapsing gas bubble on the shock-to-detonation transition in liquid nitromethane
- Nevada National Security Site (NNSS), Santa Barbara, CA (United States)
- Nevada National Security Sites (NNSS), Los Alamos, NM (United States)
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
We studied the shock-induced collapse of butane gas bubbles in the homogeneous explosive nitromethane (NM) to investigate the effects of hot spot formation on the detonation process. A butane bubble was injected into a sample of NM, and a shock wave from a flat plate impactor compressed the bubble, creating a localized hot spot. We measured shock and detonation wave speeds with optical velocimetry, and we used a high-speed camera to image the shock propagation and bubble collapse processes. A multiband optical fiber pyrometer measured the time-resolved thermal radiance, and we used the results and emissivity values extracted from spectral fits to estimate temperatures. We measured the characteristics of the shock-to-detonation transition in NM with and without a bubble. All experiments were performed at shock pressures near 8 GPa, where neat NM can detonate. A single bubble in this system was shown to sensitize NM, leading to a reduced run-to-detonation time. We used hydrodynamic modeling to predict shock wave propagation, the extent of chemical reaction, and subsequent temperature rise from the collapsing bubble. We used a temperature-dependent Arrhenius burn model for simulations, and it yielded much better results than reactive burn models that depend only on pressure and density.
- Research Organization:
- Nevada National Security Sites/Mission Support and Test Services LLC, Las Vegas, NV (United States)
- Sponsoring Organization:
- USDOE National Nuclear Security Administration (NNSA), Office of Defense Programs (DP)
- Grant/Contract Number:
- NA0003624; 89233218CNA000001
- OSTI ID:
- 2480832
- Alternate ID(s):
- OSTI ID: 2500892
- Report Number(s):
- DOE/NV/03624--2080; STIP WF - 49565055
- Journal Information:
- Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 22 Vol. 136; ISSN 0021-8979
- Publisher:
- American Institute of Physics (AIP)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
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