Hydraulic Ram Shock Wave and Cavitation Effects on Aircraft Fuel Cell Survivability.

摘要

Hydraulic ram is the dynamic loading of fuel tanks when impacted by bullets or other projectiles. During impact and penetration of the fuel cell,intense pressure waves are generated by the projectile. A ballistic range was built and experimental testing was conducted to study hyearulic ram phenomena. A 0.22caliber rifle was used to accelerate projectiles at velocities in the range of 0.38km/sec into a transparent,water filled tank. Shape and intensity of the shock wave pressure pulse induced as a result of projectile impact were determined using a dual shadowgraph system. Peak pressures were found to be as high as 4,500 x kg/sq cm. The rate of energy transfer to the fluid by the projectile was determined experimentally and compared with analytical predictions. A characteristic time was defined establishing the separation point between the shock and cabity phases of hydraulic ram. (Author)