Parametric Studies on Star Port Propellant Grain For Ballistic Evaluation

Abstract

Star port propellant grains have been extensively studied for their operating as well as geometrical parameters. It is observed that reduced tail-off and better neutrality cannot be achieved simultaneously in a configuration. Parametric study is conducted to know the effect of various parameters of star-shaped propellant grains for ballistic evaluation motor. For reduced tail-off, higher characteristic velocity, lower outer diameter of the star, and lower value of angular fraction is preferred. Star angle, burning rate, and throat diameter have negligible effects on the tail-off factor. For better neutrality, higher value of angular  fraction, higher star outer diameter, and star angle near to neutrality, is needed. An alternate configuration is suggested using this parametric study to ascertain least tail-off and enhanced neutrality.