IGNITION AND COMBUSTION OF SINGLE DROPLETS

Abstract

By means of photographic techniques, the size histories, ignition lags, and loci of ignition of small (100-300 microns diameter), single, freely falling fuel droplets suddenly exposed to a hot, oxidizing atmosphere in a furnace were determined as a function of initial droplet size, oxidizer temperature, fuel composition, and droplet spacing. The results show that ignition lag depends significantly on the temperature of the atmosphere, on the droplet-droplet spacing, and on the chemical nature of the fuel, but it appears to be only weakly affected by the oxygen concentration in the oxidizer. The ignition lag seems to be independent of the initial droplet size if the droplets are large enough to ignite at all. This characteristic insures that droplets with initial diameters smaller than a characteristic value will not ignite during their life-times. In spite of the complexity of the ignition process, the experimental results correlate satisfactorily with theoretical models that seem to represent a reasonable approximation to the physical situation of a spontaneously igniting fuel droplet.

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Document Details

Document Type
Technical Report
Publication Date
Dec 01, 1966
Accession Number
AD0808879

Entities

People

  • Bernard J. Wood
  • Willis A. Rosser Jr.

Organizations

  • SRI International

Tags

DTIC Thesaurus Topics

  • Alkanes
  • Cameras
  • Chemical Reactions
  • Combustion
  • Combustion Products
  • Energy
  • Films
  • Heat Energy
  • Heat Of Activation
  • Heat Of Combustion
  • Ignition
  • Ignition Lag
  • Photographs
  • Photography
  • Schlieren Photography
  • Steady State
  • Thermodynamic Properties

Readers

  • Atmospheric Remote Sensing.
  • Mathematics or Statistics
  • Rocket Propulsion.

Technology Areas

  • Space
  • Space - Hall-Effect Thruster
  • Space - Orbital Debris