Accession Number : ADA331744

Title :   Effect of Propellant Grain Dimensions on Progressivity

Descriptive Note : Final rept. for period ending Aug 96

Corporate Author : ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD

Personal Author(s) : White, Kevin J.

PDF Url : ADA331744

Report Date : OCT 1997

Pagination or Media Count : 52

Abstract : For high loading density propelling charges, propellant grain geometry design is employed to improve ballistic efficiency. Specifically, grains that have 7, 19 and even 37 perforations are used. These grains all have progressive geometries, i.e., surface areas that increase as the propellant burns. This report studies the effect of grain dimensions on progressivities of the 7- and 19-perforation geometries. Calculations show that for maximum progressivity, the ratio of grain diameter to perforation diameter should be as large as practical. It is shown that small values can degrade potential gun performance. Calculations also show that the grain length-to-diameter ratio should be at least between 1 and 2 for maximum progressivity. This effect is very nonlinear, and values less than 1 are shown to reduce progressivity and gun performance significantly. High-progressivity geometries have, however, an undesirable effect on ballistic temperature sensitivity and yield an increased sensitivity to propellant manufacturing variability.

Descriptors :   *GUNS, *PROPELLANT GRAINS, *MUZZLE VELOCITY, TEMPERATURE, MANUFACTURING, SENSITIVITY, BALLISTICS, PROPELLING CHARGES, PERFORATION.

Subject Categories : Ammunition and Explosives
      Guns

Distribution Statement : APPROVED FOR PUBLIC RELEASE