Accession Number : ADA318443

Title :   Experimental Demonstration of a 120-mm Ram Accelerator.

Descriptive Note : Final rept. Feb-Oct 92,

Corporate Author : ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD

Personal Author(s) : Kruczynski, D. L. ; Horst, A. W. ; Minor, T. C.

PDF Url : ADA318443

Report Date : NOV 1996

Pagination or Media Count : 36

Abstract : Ram acceleration is an emerging propulsion technology in which a projectile similar in shape to the centerbody of a ramjet aircraft engine is injected at high speed into a tube filled with a combustible gaseous mixture. As the projectile moves into the tube, under supersonic conditions, shocks occur on and around the projectile. If the gases are then ignited, either by the energy in the shock system or an external mechanism, the combustion around or behind the projectile can be self-sustaining. The net effect is to generate a localized high-pressure region around and/or behind the projectile which produces acceleration. Work at the University of Washington, Seattle, has demonstrated velocities in excess of 2.6 km/s in 38-mm caliber, while theory predicts velocities above 7 km/s may be obtainable. The first successful ram acceleration experiment at 120-mm caliber is presented. Performance at this larger caliber was as predicted from scaling considerations. Reported experiments have shown that propellant mixing by partial pressure is a viable alternative to more complex mixing schemes for obtaining homogeneous propellant mixtures in ram accelerators. The usefulness of inert firings to analyze obturator performance and shock/pressure structure in ram accelerators has been further validated. Finally, the scaling potential of ram acceleration has been firmly established with the first successful test at 120-mm caliber.

Descriptors :   *ACCELERATION, *PROJECTILES, AIRCRAFT ENGINES, FIRING TESTS(ORDNANCE), HIGH PRESSURE, REGIONS, GASES, MIXTURES, COMBUSTION, PROPULSION SYSTEMS, RAMJET ENGINES, SHOCK, SCALING FACTOR, PRESSURE, MIXING, EXTERNAL, INERT MATERIALS, SUPERSONIC CHARACTERISTICS, HOMOGENEITY, PARTIAL PRESSURE, OBTURATION(BALLISTICS).

Subject Categories : Ammunition and Explosives
      Guns

Distribution Statement : APPROVED FOR PUBLIC RELEASE