Predicting burning time variations in solid rocket motors

Factors tending to cause dispersions in solid rocket motor burning time are discussed and quantified within this paper. A theoretical treatment of burning time variability is followed by detailed discussions of each of the factors affecting the overall dispersion. Effects of variations in propellant weight, burning rate, density, characteristic velocity, and throat area are all considered. Variations in burning surface area due to port ovality, mandrel offset, and mandrel misalignment are also discussed as they affect motor burning time. Considering all of these factors, estimations for burning time variability can be made for specific solid rocket motor designs.