CJ point

All have pyramidal molecules (Cj point group for OSX2), and OSFCl is chiral though stereochemically labile. Dimensions are in Table 15.14 the short O-S distance is notable. The unstable compound OSI2 was mentioned on p. 692. 

FIGURE 11. The molecular model (Cj, point group) and torsional form of (003)2802 . The projection formula represents a view along one of the S—C bonds. 

Since the detonation velocity is equal to the speed of sound at the CJ point, Wp is determined by means of Eqs. (3.24) and (3.25). The temperature of detonation at the CJ point is higher than the temperature of deflagration because of the shock wave compression on the detonation wave. 

Though the theoretical detonation velocity and pressure at the CJ point are expressed by very simplified expressions, the computed results obtained by means of Eq. (9.7) are confirmed by measured data for RDX- and TNT-based explosives, as shown in Table 9.110 (Cp-B indicates Composition B , with the two columns relating to different particle sizes). 

Table 9.1 Density, detonation velocity, and pressure at the CJ point.

Table 9.3 shows the measured detonation velocities and densities of various types of energetic explosive materials based on the data in Refs. [9-11]. The detonation velocity at the CJ point is computed by means of Eq. (9.7). The detonation velocity increases with increasing density, as does the heat of explosion. Ammonium ni-trate(AN) is an oxidizer-rich material and its adiabatic flame temperature is low compared with that of other materials. Thus, the detonation velocity is low and hence the detonation pressure at the CJ point is low compared with that of other energetic materials. However, when AN particles are mixed with a fuel component, the detonation velocity increases. On the other hand, when HMX or RDX is mixed with a fuel component, the detonation velocity decreases because HMX and RDX are stoichiometrically balanced materials and the incorporation of fuel components decreases their adiabatic flame temperatures. 

In general, PBX materials are used for the warheads of rockets and guns. Thus, the detonation pressure pj represented by Eq. (9.7) is the most important parameter above all others. Since the detonation velocity Wj, can be measured more easily and more accurately than pj, performance is evaluated by measuring Wp, which is converted into pj by means of Eq. (9.7). Table 9.6 shows Wj, and p data, along with computed detonation pressures at the CJ point, for various HMX-PBX and RDX-PBXmaterials. 

Fig Four Curves and CJ Point Determined by RUBY Computer Program... 

In this case, reaction in the target medium ("receptor or "acceptor ) must participate in the-process of transmission thus the conditions at the interface will be determined by the intersection of the f>2 w2 curve i 1 t ie products of the priming explosive (donor), not with the p, w curve for nonreactive shocks in the acceptor, but with a curve passing thru the receptor CJ point... 

Results of Paterson s work show that the receptor (PETN) is considerably overprimed by the NG based expl, and slightly under-primed by the TNT based expl. The. reflected wave is in each case a rarefaction, very weak with the TNT explosive. The condition for no reflected wave is that the primer C-J point lie on the receptor RH curve. The condition for a stable wave in the receptor is that the receptor CJ point lie on the primer RH curve while the condition for exactly balanced priming is that the two CJ points coincide. The last condition is satisfied at every section in a single expl cartridge Fig 2 shows also, for comparison, the transmitted RH curve for nonreactive waves. The properties of such waves transmitted by the same two primers are summarized by Paterson in the table, but this part is omitted bv Dunkle and by us... 

This is the point in the reaction zone at which the CJ Condition applies. Since the cross section of an actual chge is always of a finite area, the locus of points at which the condition applies is a plane, called the CJ Plane, or other surface, CJ Surface. If the C] condition applies thruout a region of finite thickness, even though small, the more appropriate term is CJ Layer. The determination of the CJ Point for HMX/Inert (95/5) for HMX/TNT/Inert (68/30/2) is reported by J.W.S. Allan B.D, Lambourn in the 4th ONR Sym Deton (1965), p 55... 

In order to show that the stationary regime is associated with the straight line 01, which is tangent to the upper adiabat at point 2 (CJ point), Z K considered the two proximate regimes 3 4 (Fig C), which correspond to one and the same deton velocity D, since they lie on the same straight line 034. The regime 4 describes a somewhat overcompressed deton. wave, since p >p2 ... 

The effective "Chapman-Jouguet (CJ) point" on the cylindrical charge axis always coincides with the beginning of the sharp rarefaction region outlined by the heavy line in Fig 5.2 (Ref 8, p 94). If aQ is less than or equal to the distance from the wave front to this point on the charge axis, detonation will be ideal. But if it is greater than the distance h, detonation will be nonideal In this model nonideal detonation is restricted to effective reaction-zone length of a =3/8(Dt) for L [Pg.364]

Referring to curve (B) of Fig 1, note that the isentrope thru the CJ point always lies between the Hugoniot and the Rayleigh line tangent to the Hygoniot at the CJ point... 

A critical characteristic of energetic materials is the Chapman-Jouguet (CJ) state. This describes the chemical equilibrium of the products at the end of the reaction zone of the detonation wave before the isentropic expansion. In the classical ZePdovich-Neumann-Doring (ZND) detonation model, the detonation wave propagates at constant velocity. This velocity is the same as at the CJ point which characterizes the state of reaction products in which the local speed of sound decreases to the detonation velocity as the product gases expand. 

Table 5. Correlation of the fundamental vibrations v, and Vj of the point group with and Cj point groups [103, 115],...

To decompose this representation, Eq. 3.1 must be applied for each of the four irreducible representations in the Cj, point group ... 

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