Formation of Cavities and Microjets in Liquids and Their Role in Initiation and Growth of Explosion

Abstract

It is shown that micro Munroe jets can be formed at the surface of a gas bubble which has been trapped in the liquid explosive between two impacting surfaces and is being rapidly compressed. As the compression continues these jets are projected at high speed into the gas. Similar jets can be produced between two drops of explosive which are coalescing during impact. These jets may facilitate the initiation of burning both by increasing the impact velocity of the liquid and by dispersing the liquid within a pocket of compressed and heated gas. The reaction grows first as an accelerating burning. The pressure developed in this burning zone has, in the early stages, the effect of closing up and removing any cavities which may exist in the explosive directly ahead of the flame front, so that the reaction advances into a homogeneous zone of liquid that is free from discontinuities. It is not until the comparatively slow burning breaks through the homogeneous high pressure zone, and reaches a zone of liquid containing numerous cavities and bubbles, that the burning is able to transform quickly into a much faster and more violent explosion. The discontinuities are then able to sustain the rapid propagation of explosion. The bubbles of gas or cavities that are formed by the precursor waves create an environment which is conducive to the rapid transition from burning to explosion.

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Document Details

Document Type
Technical Report
Publication Date
Sep 13, 1967
Accession Number
AD0658958

Entities

People

  • F. P. Bowden
  • M. P. Mconie

Organizations

  • University of Cambridge

Tags

Communities of Interest

  • Advanced Electronics
  • Counter IED
  • Weapons Technologies

DTIC Thesaurus Topics

  • Air Force
  • Cameras
  • Compression
  • Detonations
  • Discontinuities
  • Dispersing
  • Elastic Waves
  • Explosions
  • Explosives
  • Films
  • High Pressure
  • Liquid Explosives
  • Materials
  • Photographs
  • Photography
  • Shock Waves
  • Thin Films

Fields of Study

  • Physics

Readers

  • Combustion and Flow Dynamics.
  • Rocket Propulsion.
  • Systems Analysis and Design