Grain design, propellant

One common method of designing propellent grains is to use a long annulus. This can burn on both the interior and exterior surfaces, so that as burning proceeds the outer surface decreases, but the inner suface increases in such a way that the total surface and therefore mass burning speed remains constant. Similar properties are also shown by thin flakes or discs of propellant which are suitable for use for small arms ammunition. 

Table 14.1 Design parameters of the propellant grains required to obtain Fg and Fg.

Charge Design Considerations. The selection of a propellant for a particular application is determined by cost, by the interior ballistics requirements, by propellant/weapon interface considerations, and by limitations with respect to muzzle effects. The propellant with the lowest cost formulation and the lowest flame temperature that still will meet the velocity and pressure requirements is generally used. Other important considerations are the effects on ballistic performance of various propellant grain shapes and the problem of matching the gas production rate... 

Q4 MPa s When a negative catalyst such as LiF or SrCOj was added to the AP composite propellant, combustion interruption occurred. As shown in Fig. 7.27, the pressure deflagration limit is lowered by the addition of the negative catalysts. Detailed design work of a dual-grain dual-thrust motor and the associated combustion test results are shown in Ref [5]. 

By 1803,.the British had adopted an identification system consisting of various colored letters and numbers applied to the ends of powder barrels to designate the type of propellant, the size of grain, special ingredients used in its manufacture, and method of processing. 

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