The use of these basic equations and equations derived from them in the design and analysis of propellant actuated

devices is discussed in this section.

design and development have been empirical in nature. Since most devices have been developed to meet a specific

requirement and no two are exactly alike, each new device must be designed and developed with heavy reliance on past

experience. The basic aim of this chapter is to (1) refine the first order approximations of Section II, chapter 4, and show

how they were derived, (2) provide some basic ideas which will allow development of the propellant charge design to

meet any set. requirements, and (3) provide some "rules of thumb" or experience factors to aid in some areas where

problems are commonly encountered.

devices are as follows:

propellant actuated devices. The isochoric flame temperatures of common propellants used in propellant actuated

devices range from 2,000 K to 3,300 K. The values of propellant impetus, which is a measure of the available

propellant energy, are on the order of 3X105 to 4X 105 ft-lb/lb. The densities of common double-base propellants range

from 0.055 to 0.062 lb/in.3. Propellant parameters can be computed from the propellant's chemical composition. The

important parameters are given in table XIII for several typical propellants used in propellant actuated devices.

M2 .......................................................

3319

360

1.224

0.060

4.5

M5 .......................................................

3245

353

1.226

0.060

M6 .......................................................

2570

317

1.254

0.057

2.3

M10......................................................

3000

339

1.234

0 060

3.3

T8, H8 .................................................

2306

310

1.262

0.057

1.8

n.

† These are( approximate values which satisfy the equivalence. C'P-BP

surrounding combustion products. All exposed surfaces should receive heat at the same rate and, therefore, should burn

at the same rate. This conclusion is known as Piobert's Law and was first stated for black powder. It has been verified

for solid propellants in rocket, gun, and propellant actuated device applications by examination and measurement of

partially burned grains.

burning rate, *r*. It is expressed usually in terms of inches per second. Several factors affect the burning rate, including

the pressure at which the burning takes place, initial temperature of the propellant, gas velocity over the burning surface,

and composition of the propellant.

propellants, the following relationship applies, in general, to most propellants:

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