Ignition of Fuel Sprays.
Abstract
One-dimensional unsteady calculations to study the spray ignition process were performed first for a monodisperse fuel-air spray in front of a planar heated wall and later for polydisperse single-component fuel sprays. The effect of different droplet heating models was investigated and it is found that at certain equivalence ratios ignition delay time and energies can be smaller in the heterogeneous case than in the limiting gaseous premixed case. Because of the critical dependency of ignition upon the distance of the heat source to the nearest droplet, spray ignition criteria are not precisely defined by fuel type, droplet size distribution and equivalence ratio but a range of ignition delay times and ignition energies is found due to the probabilistic effect of droplet ignition. For polydisperse sprays it was found that ignition can be well correlated with an equivalent monodisperse spray by using a mean diameter based on the total surface area of the spray and not the Sauter-mean-diameter. the experimental part of the program was designed to verify the theoretical spray ignition description and should help in understanding the physics and chemistry of the process. it focused on the importance of transport mechanisms on individual fuel droplet ignition.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1986
- Accession Number
- ADA174898
Entities
People
- H. T. Sommer
- S. K. Aggarwal
- William A. Sirignano
Organizations
- Carnegie Mellon University