Accession Number:

AD0808879

Title:

IGNITION AND COMBUSTION OF SINGLE DROPLETS

Descriptive Note:

Special technical rept. no. 8, Apr 1964-Dec 1966

Corporate Author:

STANFORD RESEARCH INST MENLO PARK CA

Report Date:

1966-12-01

Pagination or Media Count:

37.0

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.

Subject Categories:

  • Physical Chemistry
  • Photography
  • Combustion and Ignition

Distribution Statement:

APPROVED FOR PUBLIC RELEASE