DETONATION CHARACTERISTICS OF LOW DENSITY GRANULAR MATERIALS

Abstract

Consideration is given to the shock initiation and propagation of detonation in granular or heterogeneous solids. Reactions in initiating shocks were studied by measuring pressure and specific volume in the shocked state (2 to 100 kbar) for the physically similar granular reactive and nonreactive aggregates ammonium perchlorate (a low-power, insensitive explosive) and potassium chloride (an inert comparison material). Longitudinal sound velocities in compacts of the same material, over a range of bulk densities and grain sizes, were also measured. Loci of shocked states for NH4ClO4 and KCl aggregates show a dramatic qualitative difference, leading us to the conclusion that reaction occurs at the shock front. This conclusion opens the possibilities that nonreactive shocks in granular explosives and propellants do not exist, that the amount of initial reaction is related to the shock pressure, and that mechanisms of buildup to steady detonation must take into account reaction from time of shock entry. Finally, a dependence of transition behavior on grain size was demonstrated; the faster transition from shock to detonation occurs for smaller grain size, i.e., larger grain surface per unit volume.

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Document Details

Document Type
Technical Report
Publication Date
Jan 15, 1967
Accession Number
AD0647269

Entities

People

  • B. O. Reese
  • L. B. Seely
  • Marjorie W. Evans

Organizations

  • SRI International

Tags

Communities of Interest

  • Weapons Technologies

DTIC Thesaurus Topics

  • Abstracts
  • Ammonium Perchlorate
  • Chemical Reactions
  • Contracts
  • Explosives
  • Gas Guns
  • Grain Size
  • Granular Materials
  • Insensitive Explosives
  • Low Density
  • Materials Laboratories
  • Munitions
  • Ordnance Laboratories
  • Particle Size
  • Potassium Chloride
  • Propellants
  • Specific Volume

Fields of Study

  • Physics

Readers

  • Combustion Dynamics and Shock Wave Physics.
  • Combustion science or combustion engineering.
  • Materials Science and Engineering.