Three Dimensional Radiative Ignition and Flame Spread Over Thin Cellulose Fuels.
Three Dimensional Radiative Ignition and Flame Spread
Over Thin Cellulose Fuels.
(309 K)
Olson, S. L.; Kashiwagi, T.
NISTIR 6242; October 1998.
National Institute of Standards and Technology. Annual
Conference on Fire Research: Book of Abstracts.
November 2-5, 1998, Gaithersburg, MD, Beall, K. A.,
Editor(s), 67-68 pp, 1998.
Available from:
National Technical Information Service
Order number: PB99-102519
Keywords:
fire research; fire science; fire suppression;
cellulosic fuels; ignition; flame spread; space shuttle;
lamps
Abstract:
Radiative ignition and transition to flame spread over
thin cellulose fuel samples was studied aboard the
USMP-3 STS-75 Space Shuttle mission in February and
March of 1996, using the RITSI hardware. A focused beam
from a tungsten/halogen lamp was used to ignite the
center of the fuel sample while fan-drawn air flow was
varied from 0 to 6.5 cm/s. Non-piloted radiative
ignition of the paper in air was found to occur more
easily in cicrogravity than in normal gravity. Ignition
of the sample was achieved under all conditions studied,
with transition to flame spread occurring for all but
the quienscent flow condition. After ignition, the
flame spread only upstream, in a fan-shaped pattern.
The fan angle increased with increasing external flow
from zero angle (tunneling flame spread) at the limiting
0.5 cm/s external air flow, to 90 degrees (semicircular
flame spread) for external flows at and above 5 cm/s.
The downstream flame is inhibited due to the 'oxygen
shadow' of the upstream flame, despite the convective
heating from the upstream flame. Only after the
upstream flame spread was complete could downstream
flame spread occur.
