Generalized geometric analysis of right circular cylindrical star perforated and tapered grains

This paper describes criteria and formulas adopted in developing a new computer program capable of evaluating the geometric evolution of a cylindrical star grain during its combustion. This computer program, named STAR, calculates the burning perimeter (or burning area), the wet perimeter, and port area as functions of burnt thickness for a cylindrical internally cone-shaped star grain. The star configuration is defined by seven geometric parameters. These parameters can be changed along the star grain in order to simulate different internal geometric shapes. The program does not utilize a lot of computer time and it is capable of analyzing a large number of star configurations for each run. This is very useful for a geometric optimization process of the star grain. The program output is organized in a file that can be directly used as an input file for the internal ballistic program.