The Ignition and Combustion of Single Boron Particles in Air at Ambient Pressure.

Abstract

Experimental and theoretical studies are reported which provide basic information concerning the ignition and combustion processes of amorphous, crystalline, gamma-irradiated, and LiF coated single boron particles. All studies were conducted at ambient pressure with particles or particle agglomerates between 30 and 50 microns in diameter. Boron particles were suspended in a levitation cell and ignited using a pulsed neodymium-doped laser. The burning processes were recorded in either self-light or shadowgraph. Within experimental error the burning time for amorphous boron and spherodized crystalline boron are the same indicating that the initial particle character has a minor effect on the liquid droplet burning time combustion process. Analytical studies were made concerning the unsteady heating of boron particles subjected to high flux rates. The theory of nonequilibrium thermodynamics is explored and it is demonstrated that engineering calculations based on the equilibrium hypothesis may predict mass flux rates 50 to 100 percent in error. (Author)

Document Details

Document Type
Technical Report
Publication Date
Aug 01, 1971
Accession Number
AD0731241

Entities

People

  • Louise A. Cotugno
  • William H. Mclain

Organizations

  • Denver Research Institute

Tags

Communities of Interest

  • Materials and Manufacturing Processes

DTIC Thesaurus Topics

  • Agglomerates (Rock)
  • Burning Rate
  • Chemical Reaction Properties
  • Chemical Reactions
  • Combustion
  • Diameters
  • Engineering
  • Exothermic Reactions
  • Ignition
  • Neodymium
  • Particles
  • Personality
  • Thermodynamics

Fields of Study

  • Physics

Readers

  • Aerosol Science/Aerosol Physics
  • Combustion science or combustion engineering.

Technology Areas

  • Directed Energy
  • Directed Energy - Pulsed-Laser Deposition