Wind Effects on Flame Spread and Ember Spotting Near a Structure

Published

February 6, 2017

Author(s)

Kathryn M. Butler, Erik L. Johnsson, Marco G. Fernandez, Mariusz Zarzecki, Glenn P. Forney, Eric Auth

Abstract

In wildland-urban interface (WUI) fires, combustible materials pose a potential threat to contiguous or nearby structures. Flame spread and firebrand spotting have been studied in a series of field experiments involving fences and mulch beds under a variety of wind conditions and separation distances from a small structure. The rate of flame spread in a mulch bed was observed to slow significantly as the fire approached the structure, with flame contact with the structure occurring only after the gap was jumped by firebrand spotting. Computational fluid dynamics (CFD) modeling was used to gain insight into the flow field. A vortex forming near the base of the structure in the wind field was found to be responsible for changing the flame spread from a concurrent flow situation to opposed flow as it approaches the structure.

Proceedings Title

Proceedings of the 2017 Fire and Materials Conference

Conference Dates

February 6-8, 2017

Conference Location

San Francisco, CA

Conference Title

2017 Fire and Materials Conference

Pub Type

Conferences

Download Paper

Local Download

Keywords

flame spread, WUI fires, ember spotting, firebrands, mulch, flow modeling

Citation

Butler, K. , Johnsson, E. , Fernandez, M. , Zarzecki, M. , Forney, G. and Auth, E. (2017), Wind Effects on Flame Spread and Ember Spotting Near a Structure, Proceedings of the 2017 Fire and Materials Conference, San Francisco, CA, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=922470 (Accessed October 13, 2025)