Internal and transitional ballistic solution for spherical and perforated propellants and verification with experimental results

The solutions of internal ballistics in addition with the transitional ballistic equations are very important for gun design. during the design phase of a gun,some of the main parameters decided on are the selection of the propellant chemical structure and the grain geometry which may be spherical,tubular or multi perforated tubular. in this study,the résal equation,which is one of the basic internal ballistic equations,is solved by means of runge kutta method for spherical and perforated propellants. the propellant chemical structure,propellant geometry,projectile mass properties and barrel geometry are the main inputs for a typical gun design. the pressure distribution and the linear and tangential velocity of the projectile in the barrel are predicted depending on time along the barrel length. the friction force between barrel and projectile,resistance force created by the rifling against the motion of projectile are taken into consideration. thermodynamic and heat transfer parameters required in order to solve heat transfer problems of barrel such as cook-off problem are also obtained. the calculation of erosion at the inner surface of barrel is another problem solved for the life prediction of the barrel. to design a gun,solving internal ballistics is not enough,transitional ballistic of the barrel after the shot ejection has to be also solved. the computer code of “internal ballistic akçay” is generated for the solution of universal gun design problems. experiments are carried out with test barrel of 7.62x51 mm m80 ammunition at mke ballistic test facilities. the theoretical results are compared with the experimental results. the agreements between them are quite satisfactory. © 2017 tibtd printed in turkey.