Flame propagation in liquid fuel droplet arrays with forced convection
✍ Scribed by L.A. Lovachev
- Publisher
- Elsevier Science
- Year
- 1962
- Tongue
- English
- Weight
- 366 KB
- Volume
- 6
- Category
- Article
- ISSN
- 0010-2180
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✦ Synopsis
Letters to the Editors on points of scientific interest related to combustion and flames are invited. The Editors do not hold themselves responsible for opinions expressed in correspondence. Anonymous contributions cannot be accepted. Flame Propagation in Liquid Fuel Droplet Arrays with Forced Convection FLAME propagation rates in one-dimensional arrays of liquid fuel droplets burning in air without forced convection were studied previously by R. REICHENBACH, D. SQUIRES and S. S. PENNER (Eighth International Symposium on Combustion. Williams and Wilkins: Baltimore, 1962). These authors found that the propagation time was a function of the 'immersion depth' only, which was defined as the minimum depth to which an unburnt droplet is immersed in the hot-gas region of the adjacent burning droplet during the steady-state burning period. In the present work, the effect of air flow parallel to the droplet arrays on the flame propagation time has been determined experimentally.
The experimental apparatus is the same as that used by Reichenbach et al. except for facilities allowing controlled variations of forced air flow. The droplet arrays consisting of suspended n-octane droplets on quartz fibres were located on the axis of a lucite rectangular (7in. × 11 in.) duct. One end of the duct was closed except for a connection to the air supply source, and an asbestos board with a number of small holes as well as several 12-mesh screens were used in a 12 in. length of the 24 in. duct in order to calm the air stream. The entrance velocity of the air flow was varied from 0 to 13 in./sec. The rate of flame propagation was observed in both directions, i.e. upstream and downstream from the ignition source over intervals containing from 10 to 20 droplets. The flame propagation time between droplets was obtained by taking schlieren motion pictures or, more simply, by means of a stopwatch. As the scatter of the experimental data was fairly large because of the statistical nature of the phenomena, at least twenty measurements were 127