Calculating Flame Spread on Horizontal and Vertical Surfaces.
Calculating Flame Spread on Horizontal and Vertical
Ahmed, G. N.; Dietenberger, M. A.; Jones, W. W.
NISTIR 5392; 56 p. April 1994.
Available from: National Technical Information Service
Order number: PB94-187283
flame spread; computer algorithms; fire models; zone
models; test methods; lateral ignition
The flame spread model described in this paper is a new
algorithm which provdes the capability to calculate a
self-consistent fire based substantually on bench scale
fire data. The flame spread model simulates object fire
growth and burnout of a slab in a room and produces
acceptable predictions of the spread of fire, smoke and
production of both toxic and nontoxic gases. The
purpose of the flame spread model is to allow a fire to
grow realistically, possibly making a hole in the
material surface. This is one mechanism for barrier
penetration. The algorithm is based on empirical data,
gathered from standard test apparatus, including the
Cone Calorimeter and the LIFT (lateral ignition flame
spread test method). By basing the pyrolysis on test
methods, we avoid the practical difficulties associated
with an explicit calculation of radiation blocking and
material charring. The objective of including the flame
spread model is to predict the accelerative growth of a
fire from ignition to a peak value and then the gradual
termination normally seen in a fire. The intent of the
project was to develop an algorithm which could be
utilized in a complete model of a fire in a building.
The three-dimensional aspects of the flame spread model
include: first, panels made of combustible materials
with different thicknesses and at various orientations;
second, flames of two basic types, pool fire and purely
wall fire; third, a radiation heat exchange between
objects, flames, and gases. The pool fire has a flame
spreading polygon on a horizontal panel and the wall
fire is used either for inclined or vertical panels.