Detonation characteristics of diluted liquid explosives: Mixtures of tetranitromethane with methanol

Studies of the nature and mechanism of the concentration limit of detonation propagation in dilution of liquid explosives by non-explosive liquids are continued. The impact of dilution of tetranitromethane by methanol on the process of detonation was studied in a wide range of diluent concentrations. Experiments on the ignition of mixtures in steel tubes of various diameter were perfomed to obtain Data on the critical (limiting) diameters. The results obtained were compared with those from previous studies of mixtures of nitromethane with methanol and nitrobenzene. Differences caused by the chemical interaction of tetranitromethane as an active oxidizer with methanol as a fuel component are considered.     

Detonation properties of diluted liquid explosives: A mixture of nitromethane with nitrobenzene

A set of data characterizing the detonation process in mixtures of nitromethane with nitrobenzene is determined with the use of an electromagnetic method. The dependence of the pressure of detonation products on nitrobenzene concentration is established. Information on the effect of dilution ratio of nitromethane by nitrobenzene on detonability was obtained in experiments on mixture explosion. The results are compared with the results of previous similar studies of mixtures of nitromethane and methanol.     

Detonation characteristics of explosives

Moscow. Translated from Fizika Goreniya i Vzryva, Vol. 28, No. 3, pp. 69–72, May–June, 1992.     

Detonation sensitivity of liquid nitromethane doped with methyl nitrite

It has been suggested, by other workers, that the isomerization of normal nitromethane (NM CH₃NO₂) to methyl nitrite (CH₃ONO) is an important first step in the chemical kinetics of liquid NM detonation. We examine this idea by studying the effect of direct methyl nitrite addition on NM's detonation sensitivity. Failure diameter is used as the measure of sensitivity. A comparison is made between the effect of methyl nitrite addition and that of a known sensitizer of NM i.e., the NM aci ion (CH₂NO₂⁻). Methyl nitrite is found to be an ineffective sensitizer relative to NM's aci ion.     

Detonation characteristics of emulsion explosives

The detonation properties of a water-emulsion explosive are studied. The shock adiabat is determined for a density of 1.38 g/cm³. The critical diameter and the detonation velocity are found as functions of the initial density of the charge and the shock heating temperature is calculated.D. I. Mendeleev Moscow Institute of Chemical Technology, Moscow, 125190. Translated from Fizika Goreniya i Vzyrva, Vol.30, No. 3, pp. 86–91, May–June, 1994.     

Detonation characteristics of powerful insensitive explosives

Experimental and calculated detonation characteristics of powerful insensitive explosives are given. Features of explosives with a high hydrogen content are discussed. The relationship between the power and sensitivity characteristics of explosives and the structure of their molecules are considered. Prospects for the development of powerful explosives are discussed.     

Detonation characteristics of emulsion explosives sensitized by MgH2

Preliminarily results on the reaction mechanism of detonation of composite emulsion explosives sensitized by MgH₂, which simultaneously plays the role of an energetic material, are presented. Compared to emulsion explosives sensitized by glass microspheres, emulsion explosives sensitized by magnesium hydride have a different reaction mechanism of detonation. The shock wave overpressure, specific impulse, shock wave energy, and bubble energy are all greatly increased with the use of MgH₂, and it is noticeable that the shock wave overpressure and shock wave energy increase by 17% and 24%, respectively. In addition, emulsion explosives sensitized by MgH₂ improve significantly in terms of detonation velocity and brisance. These emulsion explosives also meet safety requirements.     

Detonation of a highly diluted explosive

Detonation of mixtures of PETN with quartz sand with a 10–30% content of the explosive was investigated experimentally. Such systems are characterized by a low pressure and detonation velocity. The mass velocities of the solid filler and gas of the detonation products were measured by the electromagnetic method. With an explosive content of more than 15% the process is carried out by the leading shock wave and on the whole is single-velocity. The effects of a two-phase state are substantial with a low explosive content.Lavrent'ev Institute of Hydrodynamics. Siberian Branch, Russian Academy of Sciences, 630090 Novosibirsk. Translated from Fizika Goreniya i Vzryva, Vol. 30, No. 3, pp. 124–130, May–June, 1994.     

Detonation chemistry: Diffusion control in non-ideal explosives

The performance of an explosive is a function of both the peak energy released near the detonation front, and the remainder of the energy that is released during the Taylor wave. The relative partitioning of energy between the front and the expansion, and the rate of energy release in the latter, may be controlled by either chemical kinetic or diffusion processes. Detonation calorimetry has been the principal experimental technique used to investigate these processes. Both the total energy release, and the quantitative analysis of the detonation products at a point or region on the expansion isentrope have been determined for formulations of ammonium nitrate (AN) and TNT in which both the composition and particle size of the AN have been varied. Isotopic labeling of selected explosives has also been used to give further insight into the reactions taking place in or near the reaction zone. Similar experiments have been performed in an ideal, homogeneous explosive.     

Structure of detonation waves in nitromethane and a nitromethane/methanol mixture

The results of experimental studies of the structure of the reaction zone for steady-state detonation of nitromethane and its mixtures with methanol. For pure nitromethane, the characteristic reaction time and detonation parameters were determined. For a nitromethane/methanol mixture, a dependence of the detonation parameters of the mixtures on methanol concentration is presented. It is shown that in pure nitromethane and with small additions of methanol, the detonation front is stable, or the size of the inhomogeneities of the front is less than 1 m. At a methanol concentration of 10% or higher, instability of the front is observed.     

Detonation regimes and Jouguet parameters of condensed explosives

Moscow. Translated from Fizika Goreniya i Vzryva, Vol. 25, No. 2, pp. 84–103, March–April, 1989.     

Detonation Limits of Air Mixtures with Two-Component Gaseous Fuels

The problem of detonation limits for ternary mixtures of air with a two-component gaseous fuel is considered for a detonation region represented using the Le Chatelier rule. Examples are given of incorrect treatment of conditions for detonation suppression in hydrogen–air mixtures by the addition of hydrocarbons ignoring the overall composition of the mixture. It is suggested that the range of explosion hazard of lean hydrogen–air mixtures is extended by the addition of small amounts of hydrocarbon gases. Key words: detonation, detonation limits, multicomponent fuel mixtures, suppression and promotion of detonation.