Apparatus for Automatic Determination of Gel Time

Chemical Principles of Solid Propellants

“…Oxidizer is customarily added in a blend of two or more grinds, to give a maximum loading of solids having a broad, complex distribution of particle sizes with diameters ranging from 1 to 200 microns. A typical consistency curve for a complete propellant formulation (Figure 1,4) shows clearly the non-Newtonian behavior introduced by the presence of 75% of oxidizer. The area enclosed by the ascending and descending curves, extended to some standard rate of shear, is defined as the extent of thixotropic breakdown and forms a useful parameter for correlation.…”

“…Within a longitudinal burning volume, erosion is obviously most severe nearest the nozzle, where the mean gas velocity is highest, and is negligible at the fore end. To a first approximation, the observed burning rate, r', is related to r, the zero-velocity burning rate at the same static pressure, by rj = 1 + hu (10) in which u is the space-mean linear gas velocity and k is a constant characteristic of the propellant. Typically, the term k\U equals several tenths.…”

“…Thermochemistry Criteria of Performance. The best single criterion of the propulsive capability of a rocket is probably the boost velocity, vb: Db = v In (' + S) (1) where v is effective exhaust velocity of product gases; Mp, mass of unburned propellant; and A/,•,''mass of inert parts, including payload. This equation w-as derived for ideal conditions, neglecting the effect of gravity and air drag and assuming a start from rest.…”