Research on interior ballistic mechanics of electromagnetic railgun

Low efficiency of energy utilization is one of the most important bottlenecks for the electromagnetic railgun to go into application. While any improvement in emission efficiency presents amplifying effect in saving the overall energy, so it is very necessary to reduce aerodynamic losses generated during the projectile emission. In this paper, the view of interior ballistic aerodynamic losses in the emission of electromagnetic railgun is introduced. Through mathematical analysis and dynamic mesh CFD (computational fluid dynamics) simulations, explore the interior ballistic law and optimize aerodynamic shape of the projectile. The interior ballistic researches show that improving the electromagnetic force and the aerodynamic drag ratio can improve the emission efficiency of electromagnetic railgun, increasing the clearance between projectile and barrel can reduce the aerodynamic losses. For the aerodynamic shape, increasing the slenderness ratio, reducing the cone angle and so on can reduce aerodynamic losses. What´s more, through the researches, we found that the aerodynamic optimizations are more valuable for large high-velocity projectile.