Velocity — Charge Diameter Relationship

Lafitte (Ref 2), vel of deton generally increases with the diam of cartridge up to a maximum value, above which the vel remains constant. This is true for PA, RDX and for AN/Tetryl mixts contg more than 10% Tetryl, but for some other expls, such as PETN and Tetryl, the curve of deton vel vs cartridge diam increases at first, passes thru a maximum, then decreases and, after passing thtu a minimum, rises again 

Jones (Ref 4) has proven that vel of deton wave in a cylindrical chge is dependent on its 

Jones also detd deton vels for various AN/TNT mixts of ca.1.6 density and found that vel decreased with diam of chge and TNT content. For mixt contg only. 30% TNT, no deton took place at 0.75 in diam of chge (quoted from Ref 5, pp 140-41) 

Summarizing the work done to ca 1950, Taylor (Ref 5, p 142) stated that the results show that the max or hydrodynamic vel of deton is approached as the diam is increased, but as the diam is reduced the vel fails. Eventually the vel becomes so low that die deton wave is not strong enough to maintain its own propagation. There is, therefore, a critical minimum diam for any expl below which a self-sustained deton wave will not propagate. The critical vel and critical diam bear no direct relation to.the hydrodynamics of deton. They are dependent on an ill-defined prop of the expl which is called sensitiveness .  

This prop is not completely detd by the chem nature of the expl but is closely related to its physical state. In some solid expls the critical diam depends on the fineness of the particles, the finest or most finely aerated materials giving the lowest critical diams. 

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Critical Charge Diameter-Detonation Velocity Relationship. See under Detonation Velocity-Charge Diameter Relationship... 

Density - Detonation Velocity - Diameter of Charge Relationships. See under Detonation Velocity - Charge Density Relationship and Detonation Velocity - Charge Diameter Relationship... 

Also under Detonation Velocity-Charge Diameter Relationship, Vol 4, p D641-R and Vol 3, p C560-R and C561-L. For information on critical diameters of a)Iiquid explosives,... 

Detonation velocity-charge diameter relationship 4D641... 

Detonation-Critical and Limiting Charge Densities, Charge Diameters and Detonation Velocity Relationships. See under DETONATION VELOCITY-CHARGE DIAMETER-DENSITY RELATIONSHIPS... 

Fig 3-2, p 47 gives velocity versus density of the above expls, while Fig 3.3 deals with velocity vs diameter for the same expls. Both of these Figs are reproduced here as Figs 1 2 under DETONATION VELOCITY-CHARGE DIAMETER AND DENSITY RELATIONSHIPS. These curves were obtd at large enough.diameters to ensure ideal deton... 

DETONATION VELOCITY-CHARGE DIAMETER AND DENSITY RELATIONSHIPS... 

For determination of critical diameters, the test s described under Detonation Velocity-Charge Diameter and Density Relationships, Experimental Procedures can be used... 

Detonation Velocity, Influence of Charge Diameter on. See Detonation Velocity, Charge Diameter and Density Relationships... 

Limiting (or Critical) Charge Density-Diameter of Explosive Charges. See Detonation Velocity-Charge Diameter and Density Relationship in Encycl 4 (1969), D641-L to D656-L... 

Detonation Velocity - Charge Diameter and Density Relationship (pp D646-L to D654-R) Detonation Velocity and Chemical Composition and Detonation Velocity as a Function of Oxygen Balance and Heat of Formation (pp D656-L to D657-L)... 

Detonation velocity-charge diameter and density relationships 4 D646... 

Taylor (1952), 139-55 (Deton vel-charge diam relationship) 7) M.A. Cook et al, "Velocity-Diameter and Wave Shape Measurements and the Determinations of Reaction Rates in Metal Nitrate-TNT Mixtures , Univ of Utah Inst for Study of Rate Processes,... 

Most of this section on relationships between charge densities, charge diameters and detonation velocities was compiled using the reports and papers listed in CA up to 1961. 

X-ray absorption furnishes an absolute measure of the density of matter. However, in many applications the important observations to be made with X-rays concern the geometrical relationships of shock fronts and contact surfaces it is in this area where X-rays, because they make it possible to sefe inside the detonating expl, provide a uniquely appropriate tool. Until recently the difficulty has been the inability of available sources to penetrate charges more than a few inches in diameter. With the advent of the PHERMEX machine this difficulty has been overcome. Phermex provides a pulsed beam of 27 Me V electrons in 0.1 microsec bursts, which impinge on a tungsten target to generate X-rays that can easily penetrate several cm of HE. Recall that density of the shocked material can be related to particle velocity thru the conservation equations (see Vol 7, HI 79)... 

When the linear portion of the relationship is extrapolated to Md= 0, we find the value of the detonation velocity for an infinite diameter (uniaxial) charge. 

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