Detonation critical diameter for

Critical diameter for detonation propagation from a narrow channel to... 

The critical diameter for detonating pure, liquid HN3 at ambient temperature is 0.08 mm based on experiments in capillary tubes. A further decrease of the diameter first leads to deflagration and then prevents decomposition [76]. 

Knystautas, R., J. H. Lee, and C. M. Guirao. 1982. The critical tube diameter for detonation failure in hydrocarbon-air mixtures. Combustion and Flame. 48 63-83. 

In the preceding sections we have emphasized the importance of knowing the heats of formation of explosive materials in order to estimate AH, detonation product compositions, fire explosion hazards of potentially dangerous materials, and critical diameters for thermal explosions. This is by no means a complete list of the uses of heats of formation. Thus the AHf° of a compound is indeed one of its most useful properties. However, how does one proceed if the AHf° for a material of interest has not been determined experimentally The obvious answer to this is by estimating AHf° on the basis of theoretical or semi-empirical methods. Many such methods exist. The following article contributed by Dr. Robert Shaw of SRI presents a method that is particularly applicable to estimating the heats of formation of explosive compounds... 

The uses of thermochemical data in estimating heats of detonation, detonation product compns, fire and expin hazards and critical diameters for expls were reviewed earlier (Vol 7, H38-L ff). For instances where heats of formation of organic expls are lacking, their estimation from group activities was described in Vol 7, H47-L ff A method for linking thermochemical data to the prediction of hazards was presented in Vol 7, HI 5-L to H23-L. The reader is directed to this article for a discussion of the complexity of the subject. For a further exposition of the problem, see Safety in the Energetic Materials Field in this Vol... 

Small scale, unconfined detonation rate sticks were tested at 3.00 0.03 mm and 6.35 0.03 mm pellet diameters. The ETN pellets were pressed to an initial average density of 1.74 0.01 gem 3 (98% TMD), and pellet expansion was not measured thereafter. These measurements gave a detonation velocity of 7.90 0.13 and 8.03 0.04 mmps 1 at 3.00 and 6.35 mm respectively, which are within uncertainty of the adjusted detonation velocities observed in the cylinder tests, given in Table 1. These velocity measurements demonstrate a critical diameter for ETN of <3 mm, which is consistent with the PETN critical diameter of<1 mm [9]. 

Another example of geometrical limitation is a spherical detonation initiation in an open space by a detonation wave diffracting out of a tube or a rectangular cross section duct into the space. In [1,2] it was found that the induction zone length A in the ZND model is proportional to the transverse detonation cell size (width) a. The experiments revealed that the critical tube diameter for initiation is at least 13 transverse waves [30]. As this takes place, the critical diameter of detonation initiation can be found from ... 

Critical Diameter. The crit diam for deton propagation in iron tubes is 25mm, in brass 7mm (Ref 31)... 

Analytical A proc is described for the quant titrimetric analysis of TeNMe in nitric acid (Ref 35)s and a spectrophotometric method is described in Ref 41 for the detn of small amts of TeNMe in air and w Critical Diameter. The crit diam for deton propagation of TeNMe thickened with poly-(methyl acrylate) and loaded with up to 75% inert solids was detd and found to decrease with increasing solids loading. It was postulated that the solids acted as reaction foci ahead of the deton front (Ref 45)... 

Critical Diameter (which will propagate a detonation). The min diam for dry AP, wet with acet, and wet with et ale, was found to be under 2 inches when confined, and under 4 inches when unconfined (Ref 24)... 

Critical diameter, dc, is the diameter below which steady detonation is impossible. For PA,... 

Pressure, Detonation. Detonating condensed expls develop very-high pressures. For most military expls and many of the commercial expls the pressures attained within the expl column do not depend on confinement, provided the column diameter is appreciably larger than the critical diameter of the expl. This confinement-independent pressure associated with a steady detonation is called the Chapman-Jouguet pressure or PCJ... 

Critical detonation diameters for mixtures have been determined. 

A series of mixtures of nitric acid with one or more of mono- and di-nitrobenzenes, di- and tri-nitrotoluenes have been shown to possess high-explosive properties [1]. Critical detonation diameters for mixtures of nitric acid with dinitrotoluene and TNT have been determined [2],... 

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