Detonation of Liquid Explosives

Detonation is a process in which chemical changes occur inside explosives or flammable mixtures, whose process has some similarity with combustion. The feature of detonation is that chemical reactions do not occur within the materials at 

From detonation physics, the charging and application of liquid explosives are not as wide as condensed explosives because liquid explosives are not compressible. Liquid explosives have an elusive outstanding feature, which is that the reactions of detonation absorb energy first, later release heat. The combination of exothermicity and endothermicity complicates the chemical reactions, and results in the parameter distribution characteristics of macrokinetics different from detonation characteristics of general high-energy explosives. 

To study the detonation of liquid explosives and its spreading/transportation, nitromethane, nitroglycerine, diethyleneglycol dinitrate, and methyl nitrite are designed as the objectives of liquid explosives to study the chemical dynamics and the complex unsteady process of shock waves combustion. These phenomena determine the structure of detonation wave fronts and spreading limit of detonation waves. They help to clear the flow dynamics of wave fronts, and refer suggestions for the formula of liquid explosives, study and application of equipment features. They help to improve and perfect the detonation theory. 

To simplify the study, five explosives are designed. Same amount of tetrani-tromethane, nitroglycerine, diethyleneglycol dinitrate, methyl nitrite, and AstroliteG (hydrazine nitrate 59 %, hydrazine perchlorate 24 %, hydrazine 10 %, and methylamine 7 %) are initiated at exactly same conditions. At the same time, the same inert solvents are used to dilute the above five explosives to conduct the contrast experiments. It mainly explains the energy release of wave fronts at different time. First-hand information is obtained by this way. The equipment setup is shown in Fig. 2.5. 

5 metal pipe with liquid explosives 6 illuminated 

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Critical Phenomena in the Detonation of Liquid Explosives. This subject is discussed by A.N. Dremin in the 12th SympCombstn(1968), published in 1969, pp 691-99... 

Heat Pulse. (Also see Detonation, Flash-Across, Heat Pulse and Hypervelocity Phenomena in Vol 4, p D348-49). A concept advanced by M.A. Cook (Refs 1 2) to provide a theoretical mechanism for the shock initiation of explosives. Cook also used the heat pulse concept in his explanation of certain unusual luminosity effects observed primarily in the detonation of liquid explosives. Briefly stated, Cook believes that detonation is initiated when as a result of rising temperature, produced by reaction in the already shocked region of an explosive, a portion of the explosive becomes thermally super-conductive and a heat-pulse flashes thru it and catches up with the shock front. Studies conducted by Kendrew Whitbread (Ref 3) tend to discount the necessity for postulating a heat-pulse in a theoretical explanation of shock initiation or the above unusual luminosity effects. More recent studies of shock initiation have also failed to produce any conclusive evidence of a heat-pulse ... 

According to a, pj, and <5 values from experiments, the calculated mass burning rates of methyl nitrite, diethyleneglycol dinitrate, and nitroglycerine in one standard atmosphere press are 0.25, 0.26, and 0.25 g/cm s, separately. It is concluded that the right side of Eq. 2.19 is approximated as a constant. If the pressure is 1 atm, it is 0.25 g/cm s. When the burning rate is over 0.25 g/cm s, detonation of liquid explosives is possible. 

Because shock waves from liquid explosives have a stronger influence than that of condensed explosives with the same mass and especially in closed or semiclosed space, we started to investigate the characteristics of self-sustaining detonation of liquid explosives, as well as the underlying detonation mechanisms. 

The detonation of liquid explosives is different from that of general condensed explosives. In common, for same mass/weight of explosives, liquid explosives do more work than condensed explosives. The under-pressure detonation of self-sustaining spreading is studied below. 

After the detonation of liquid explosives, the detonation rate is determined by the inclination/dip angle of Rayleigh line, which is tangential to the detonation adiabatic curve with the most heat released. The detonation pressure is determined by... 

Fig. 2.11 Schematics of five parts, which compose the structure of under-pressure detonation of liquid explosives...

Above, the special detonation of liquid explosives is discussed. In the detonation wave range of under-pressure detonation, there is constant flow area— the flat-form of pressure. After the feature is proved, there will be potential applications in explosion industry. 

This book will discuss the detonation of liquid explosives—the first exothermic reaction, and the second exothermic reaction and endothermic detonation, which is one example of eigenvalue detonation. This case has application value because most of solid explosives are composed by one kind of explosives and a mixture, which deactivates adhesives. In the detonation, the deactivation of adhesives is endothermic. The eigenvalue detonation of this kind of explosives is achievable. Figure 2.15 explains the key features of the eigenvalue detonation. 

The piston is introduced to discuss the detonation of liquid explosives [17]. Compared to the key features of condensed explosives, the piston issues/cases of liquid explosives are a little more complex. Based on different piston rates Pp have... 

When the detonation products stop expanding and contract back, the air shock waves separate with the detonation products and propagate independently. For the detonation of liquid explosives, the separation occurs at about the place, which is 10-15ro. Now the pressure of air shock wave fronts is 10-20 kg/cm and the propagation velocity is 1,000-1,400 m/s. The mass velocity after fronts is 800-1,400 m/s. Figure 2.28 gives the pressure distribution of shock waves. 

Parameter Calculation of Shock Waves Produced by Detonation of Liquid Explosives in Free Space [23, 24]... 

Detonation characteristics of liquid explosive mixtures with nitrobenzene were studied. 

The cyanide is a friction- and impact-sensitive explosive, and may initiate detonation of liquid hydrogen cyanide. Other heavy metal cyanides are similar. 

The superheated liquid concept, in any case, may only supply a local trigger to initiate the RPT. Other ways to trigger such events are possible, e.g., detonation of small explosive charges can sometimes be employed. To produce large-scale, coherent RPTs, the trigger may cause collapse of vapor films in adjacent masses of volatile liquid and lead to the escalation of the small triggering event. 

Condensed expls, reaction zone) 8) Baum, Stanyukovich Shekhter(1959), 664-753 (Expln in condensed media) 9) A. Vidart MP 42, 83-144 (I960) (Calcn of characteristics of condensed expls) 10) Andreev Belyaev (I960), 193-210 (Deton of condensed expls) 11) L.G. Bolkhovitinov, DoklAkadN 130, 1044-46(1960) (Low-speed deton of liquid expls) 11a) 3rdONRSymp-Deton(1960), pp 469 98, A.W. Campbell et al, "The Shock Initiation of Detonation in Liquid Explosives 12) R.F. Chaiken, JChemPhys 33, 760(1960) in 3rdONRSymp-Deton(1960), pp 304-08 (Comments on hyper-velocity wave in condensed expls 12a) Zel dovich Kompaneets (I960), Chapter 4 (Detonation in condensed expls) 13)... 

Detonation in Liquid Explosives - The Low-Velocity Regime , Ibid, pp 117-25 19e) S.D. Gardner J. Wackerle, "Interactions of Detonation Waves in Condensed Explosives , Ibid, pp 154-55 19f) W.E. 

Detonation of High Explosives. See under Detonation (and Explosion) of Condensed (Liquid and Solid) Explosives... 

Spherical detonation waves can also be produced by condensed expls (solid ot liquid), especially if the charges are spherical in shape and they are initiated in the center. The above discussion of Baum et al applies to both gaseous and condensed expls. Addnl information on spherical detonation of solid explosives can be obtd from the works of Landau 8c Stanyukovich (Ref 2), Jones Miller (Ref 3), Wecken Sc Muecke (Ref 4a), Lutzky (Ref 26), Rudlin (Ref 26a) and Green James (Ref 27)... 

Modes a), b) c) presumably operate in the usual impact and/or friction initiation of pressed solid explosives, and modes a) b) in the impact and/or friction initiation of liquid explosives. Modes e), f)> g) h) operate in the shock initiation (and possibly the propagation) of detonation in solid explosive compacts or explosive liquids containing inhomogeneities. 

Sensitivity and Hazards ofLP. Some mono-proplnts and some well-mixed biproplnts exhibit detonation characteristics typical of Liquid Explosives (See Sects 4 5 of article on Liquid Explosives in this Vol). However, biproplnts usually do not sustain complete detonation, ie, a rather small portion of the biproplnt undergoes something akin to detonation and the remainder deflagrates (Ref 26). Of course even this partial detonation can be very dangerous and destructive. LP are also subject to another phenomenon which is potentially destructive (at least to the rocket), namely combustion instability (Refs 16 22)... 

Explosion of Liquid Explosives. See cross-refs in Vol 4, pp D424-R D425-L and R.F. Chaiken, AstronauticaActa 17, 575—87 (1972) (On the Mechanism of Low-Velocity Detonation in Liquid Explosives)... 

Explosive Mixtures, Detonability of. A study of detonability of liquid binary and ternary mixts of NMe(Nftro methane), hydrazine and methanol showed that hydrazine strongly sen sitizes NMe and NMe-methanol mixts to de-... 

Usually prilled ammonium nitrate is used as it facilitates detonation of the explosive and the porosity of the granules help to retain the liquid ingredient. 

The role of radical anions in the detonation of nitroaromatic explosives has been examined.215 The potassium salts of such radicals were formed by mono-, di-, and tri-nitrobenzenes and -toluenes in liquid ammonia solution and, on removal of the solvent, render the material highly susceptible to loss of the metal nitrite, which increases with nitro substitution. Cleavage of the C—N02 M+ bond follows the regioconserved or... 

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