Shock-to-detonation transition of nitromethane: Time-resolved emission spectroscopy measurements

Abstract

The objective of this work is to improve the knowledge of the shock-to-detonation transition of nitromethane. The study is based on a spectral analysis in the range 0.3-0.85 µm, with a 28-nm resolution, during experi-ments of plane shock impacts on explosive targets at 8.6 GPa. The time-resolved radiant spectra show that the detonation front, the reaction products produced during the superdetonation, and the detonation products are semitransparent. The temperature and absorption coefficient profiles are determined from the measured spectra by a mathematical inversion method based on the equation of radiative transfer with Rayleigh scattering regime. Shocked nitromethane reaches at least 2500 K, showing the existence of local chemical reactions after shock entrance. Levels of temperature of superdetonation and steady-state detonation are also determined.

An experimental and kinetic modeling study of a premixed nitromethane flame at low pressure

“…The understanding of the NM flame structure and burning behavior is believed to further enhance the understanding of the hexogen (RDX) [4] and nitro compound flames. For these reasons, NM has been investigated extensively in detonation studies [5][6][7]. In contrast, studies pertaining to the combustion process of NM are scarce [4,8], despite few previous studies on its pyrolysis [9][10][11][12][13] and oxidation [14].…”

Influence of nitromethane concentration on ignition energy and explosion parameters in gaseous nitromethane/air mixtures

“…Up to now, a lot of works have made a contribution to the study of nitromethane as one component of liquid explosives [1][2][3][4] and propellants [5][6][7], and obtained a good knowledge of the characteristics of its combustion and explosion. Some works have also paid attention to the explosion process of gas-liquid two-phase and gas-liquid-solid three-phase within the pipe with a large length diameter ratio [8].…”

Temperature measurements of expansion products from shock compressed materials using high-speed spectroscopy

“…The radiative emissions in turn will be proportional to the temperature and the temperature gradient in the radiating body. Time-resolved spectroscopy has been performed on homogenous transparent liquid explosives while in confinement at high pressures [7,8]. It is quite evident that temperature determination based on thermal radiation emitted by the explosive requires knowledge of the emissivity, and the particle size of the debris products in the debris cloud.…”

“…Previous studies on homogenous explosives [7][8][9], utilized emission spectroscopy to study some of these aspects. However, these studies have been on confined liquid explosives where the explosive phenomenon is observed through a window material and at relatively low shocked pressures (less than 20 GPa).…”