Application of CFD Modeling to Room Fire Growth on Walls.
Application of CFD Modeling to Room Fire Growth on
Liang, K. M.; Ma, T.; Quintiere, J. G.; Rouson, D.
NIST GCR 03-849; 86 p. April 2003.
Sponsor:National Institute of Standards and Technology,
Available from:: National Technical Information Service
(NTIS), Technology Administration, U.S. Department of
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computational fluid dynamics; room fires; walls; fire
growth; fire plumes; flame spread; burning rate;
computer programs; compartment fires
An evaluation of the NIST FDS model was conducted with
particular attention for its use in predicting flame
spread on surfaces. Over the course of this
investigation the computational model changed from
combustion depicted by particles to a mixture fraction
based combustion model. The study pertains to version
2.0 released on December 4, 2001. Three aspects were
considered in the study. First, we studied the
evaluation of the code to predict a combusting plume.
Second, the code was applied to a fire plume adjacent to
a vertical wall, and then flame spread on the wall.
Third, a complementary investigation of an improved
algorithm for convective heat transfer at a surface was
developed. The first two studies resulted in M.S.
theses. Damian Rouson of CCNY performed the third study.
The thesis by Ma on the axi-symmetric plume was
previously transmitted and will not be included here.
However, a recently accepted paper, based on the thesis
with updated results is included. The general
conclusions are that the FDS code is very good for
computing the fluid dynamics, entrainment and flame
height. The temperature in the combustion region appears
to be over-estimated at the base of the geometry
considered, and any related heat flux is consequently
over-predicted. The temperature results are grid
dependent. A computation of flame spread on vertical
PMMA gave mixed results. The code was benchmarked
against fire plume correlations after a review of the
literature to obtain the most general results. Most of
the experimental correlations have some deficiencies,
and should be improved. Particular attention needs to be
given to temperature measurements in the flame since
these are generally under-estimated due to radiation
error. The wall heat flux and flame spread comparisons
were made against data we viewed as quality data. The
algorithm developed by Rouson is based on the
theoretical formulation by Howard Baum, and has not been
tested in the FDS code.