Combustible cases

Two processes may be used in the manufacture of combustible cases the original post-impregnation process and the more recently and more widely employed beater additive process. The processes differ primarily in the point at which the required resin is added to the composition. A schematic of the beater additive process is shown in Figure 11. 

We shall retain this assumption even for the high-temperature combustion case, realizing that it is quite severe. However, its neglect will undoubtedly be compensated through ultimate experimental correlations. With assumption 7 we approximate... 

Compositions of some combustible and semi combustible cases were described by Gen W.K. Gormley in Ordn 47, 231—34(1962)... 

One disadvantage of a combustible case is that it does not perform the function of sealing off the rear end of the gun tube, which prevents ieakage of the high-pressure propeiiing gases. 

The work on cast combustible cases was discontinuedfprobably in 1962), because the Combustible Cartridge Case Steering Committee decided to concentrate all efforts on the felted NC type of cases(Ref 20, p4)... 

It has been known for sometime(See Ref la) that NG will migrate from proplnts (double- or triple-base) into the combustible case and be absorbed by the NC, thus gelatinizing it. As this migration affects the physical props of the cartridge case, it should be prevented as much as possible. One of the methods to stop such migration is to coat the inside of cartridges with a barrier material. Axelrod found that a mixture of Methylcellulose (MC Std 15cps) 5.0,... 

Some cartridge cases are made of combustible materials (e.g., paper, plastic) that leave no residue or spent case to be removed from the device, tool, or weapon. In transportation terms, however, true combustible cases are those made of nitrocellulose which, being an explosive, adds force to the overall power of the explosive charge as well as leaving no residue. 

In all these instances, a cartridge may either be consumed in its entirety or for ballistic reasons a metal base used, leading to a partially combustible case. The advantages of a combustible case are obvious. Enormous amounts of strategic metal would be released for other purposes and there is no question of collection and reuse of such metal. Special benefits are derived for the gunner within a tank The hot used metal cases are an encumbrance in the close quarters, and residual toxic gases from burned propellant powder remain in the conventional metal cases. 

Figure 10.10a shows propane conversion contours obtained from 2D CFD calculations for catalytic propane combustion in a non-adiabatic microchannel for the conditions mentioned in the caption [23]. Unlike the homogeneous combustion case, the preheating and combustion zones in catalytic microburners overlap since catalytic reactions can occur on the hot catalyst surface close to the reactor entrance. Figure 10.10b shows a discontinuity in the Nu profile, similar to the homogeneous combustion problem. In this case, it happens at the boundary between the preheat-ing/combustion zone and the post-combustion zone. At this point, the bulk gas temperature (cup-mixing average) and wall temperatures cross over and the direction... 

Figure 5.9 Comparison of isooctane conversion achieved in a microchannel steam reformerwith integrated catalytic burnerfor isooctane combustion (case A), and a microchannel steam reformersupplied withenergyfrom hotcombustion gasesfed into heating channels (case B) [383] S/C ratio was 3.0 in both cases the air excess was 20% in case A and 94% in case B.

The comparison with the similar formula for polymers synthesis [7] shows their principal distinction the higher (in about 4 times) constant coefficient in the combustion case at the expense of process temperature enhancement. Let ns note, that the exponents a and P are interconnected according to the Eq. (2) combnstion front jumps ( Levy s flights ) intensity reinforcement resnlts in a growth and, hence, to fractal time x enhancement and vice versa. 

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