Accession Number:

ADA158560

Title:

Multiple Ignition, Combustion and Quenching of Hydrocarbon Fuel Sprays.

Descriptive Note:

Annual rept. Jul 83-Jul 84,

Corporate Author:

CARNEGIE-MELLON UNIV PITTSBURGH PA DEPT OF MECHANICAL ENGINEERING

Report Date:

1984-08-01

Pagination or Media Count:

14.0

Abstract:

A detailed parametric study of the ignition of a monodisperse fuel-air spray in contact with a hot wall was conducted. The theoretical model was one-dimensional unsteady and employed a hybrid Eulerian-Lagrangian numerical scheme. Effects of drop size, chemical kinetics, fuel-air ratios, fuel type and other parameters were examined. The results indicated the statistical character of the spray ignition, the existence of optimum droplet size and optimum fuel-air ratio for the minimum ignition delays. The study was extended to the polydisperse spray. The major conclusion was that the polydisperse results can be correlated with an equivalent monodisperse spray represented by a mean diameter based on the total spray surface area. The study of ignition for sprays flowing over a hot plate as initiated. The formulation and the numerical coding were completed. Currently the code is being employed to predict the ignition delays for the flowing sprays. Preliminary experiments were conducted to investigate the ignition of a single droplet stream along a heated surface. The results show an optimal distance from the surface for the droplet stream. It is speculated that this distance depends on the characteristic evaporation time, diffusion time and convective time inherent to the system. Experiments separating the effects are underway to investigate this interactive process. Author

Subject Categories:

  • Combustion and Ignition
  • Fuels

Distribution Statement:

APPROVED FOR PUBLIC RELEASE