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Qualitative flow visualization of flame attachment on slopes

Author(s): Torben Grumstrup, Sara S. McAllister, Mark A. Finney
Year Published: 2017

Heating of unburned fuel by attached flames and plume of a wildfire can produce high spread rates that have resulted in firefighter fatalities worldwide. Qualitative flow fields of the plume of a gas burner embedded in a table tilted to 0°, 10°, 20°, and 30° above horizontal were imaged using the retroreflective shadowgraph technique as a means to understand plume attachment and related behavior. Tilting of the plume in the uphill direction for all non-zero slopes was explained by an imbalance in the flow of air entrained into the plume. Reversal in direction of fluid flow uphill from the flame front was shown to occur when buoyancy forces overwhelmed entrainment flow momentum. Flame and plume attachment was explained as being caused by uphill flow of hot combustion gas driven by a combination of buoyancy and an uphill pressure gradient.

Citation: Grumstrup, Torben P.; McAllister, Sara S.; Finney, Mark A. 2017. Qualitative flow visualization of flame attachment on slopes. Presented at the 10th U. S. National Combustion Meeting Organized by the Eastern States Section of the Combustion Institute; April 23-26, 2017; College Park, MD. Pittsburgh, PA: The Combustion Institute. 6 p.
Topic(s): Fire Behavior, Fire Prediction
Ecosystem(s): None
Document Type: Book or Chapter or Journal Article
NRFSN number: 16566
Record updated: May 16, 2018