Blast Effects on Fires
Abstract
Experiments on extinction of fires by airblast were conducted in the shocktube facility dedicated to blast/fire interaction studies. Three series of tests were conducted to gain practical understanding (quantitative and mechanistic) of blast effect on fires, using: (1) liquid-fuel fires of various sizes; (2) liquid-fuel fires, of various sizes, with flow-obstructing barriers upstream of the fuel source; and (3) wood-crib fire tests. Results affirm the concept of flame displacement as a mechanism of extinguishment for liquid-fuel fires on flat surfaces but suggest its limitation in describing blast/fire interactions when flow-perturbing obstacles are present upstream of the fuel bed. Even small barriers are seen to significantly increase the fire resistance to blowout by blast, by providing flame-retentive flow recirculation in their wake and effectively serving as flame-holders. For charring fuels such as wood cribs, after-shock flame displacement is seen to be augmented by sustained, blast-enhanced char involvement. The crib fire history before blast arrival and the extent of char-combustion enhancement (depending on blast strength) determine whether the crib fire is reestablished by rapid rekindling.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1980
- Accession Number
- ADA104135
Entities
People
- Jana Backovsky
- Robert Mckee
- Stanley B. Martin
Organizations
- SRI International