On the Use of a Firebrand Generator to Investigate the Ignition of Structures in Wildland-Urban Interface (WUI) Fires.
On the Use of a Firebrand Generator to Investigate the
Ignition of Structures in Wildland-Urban Interface (WUI)
Fires.
(5372 K)
Manzello, S. L.; Shields, J. R.; Yang, J. C.; Hayashi,
Y.; Nii, D.
Volume 2;
Interflam 2007. (Interflam '07). International
Interflam Conference, 11th Proceedings. Volume 2.
September 3-5, 2007, London, England, 861-872 pp, 2007.
Keywords:
fire brands; ignition; structures; wildland/urban
interface; experiments; size distribution; mulch;
forestry; flow fields; vents
Abstract:
An experimental apparatus has been constructed to
generate a controlled and repeatable size and mass
distribution of glowing firebrands. The present study
reports on a series of experiments conducted in order to
characterize the performance of this firebrand
generator. Firebrand generator characterization and
subsequent structural ignition experiments were
performed at the Fire Research Wind Tunnel Facility
(FRWTF) at the Building Research Institute (BRI) in
Tsukuba, Japan. The firebrand generator was fed with
mulch generated from Korean Pine trees. To produce
repeatable initial conditions for each experiment, the
Korean Pine mulch was sorted using a series of filters
prior to being loaded into the firebrand generator. The
size and mass distribution of firebrands produced from
the generator was tuned to be representative of
firebrands produced from burning trees. After the size
and mass distribution of firebrands was characterized,
the device was then used to direct firebrand fluxes
towards a structure installed inside the FRWTF. A gable
vent was installed on the front face of the structure
and three different steel screens were installed behind
the gable vent to ascertain the ability of the screen to
block firebrands from penetrating into the structure.
The mechanism of firebrand penetration through screens
was observed for the first time. The firebrands were not
quenched by the presence of the screen and would
continue to burn il they were able to fit through the
screen opening. Results of the study are presented and
discussed.
