Ram accelerator optimizaiton and use of hydrogen core to increase projectile velocity

摘要

The maximum ram accelerator velocities achieved to date are slightly under 3 km/s. this present paper analyzes projectile design and the use of the hydrogen core technique for ram accelerator operation between 3 and 7 km/s. Projectile structural design is studied; hollow, solid and two-material projectiles made of Mg, Al, Ti, steel, Ta and Re are analyzed to detemrien the maximum accelerations which can be reached. These projectiles are then analyzed for gasdynamic heating and the distances along the launch tube until the projectile surfaces reach the ignition and melting points are determined. The projectile surface is found to reach the ignition and melting temperatures after traversing small fractions of the necessary tube length. The use of a hydrogen core in the ram accelerator tube to reduce the heat flux to the projectile is studied. A new vortex technique is presented. With a projectile with a TA or Re shell in a hydrogen core, on should be albe to make the projectile survive up to alunch velocities of 7 to 10 km/s.