Theoretical and Experimental Study on Fully-Developed Compartment Fires.
Theoretical and Experimental Study on Fully-Developed
Compartment Fires.
(12252 K)
Utiskul, Y.
NIST GCR 07-907; 206 p. February 2007.
Sponsor:
National Institute of Standards and Technology,
Gaithersburg, MD
Keywords:
compartment fires; fire growth; burning rate; fuels;
vents; mixing; zone models; formulation; mathematical
models; experiments; wood cribs; heptane; pool fires;
heat of gasification; fire models; ventilation
Abstract:
To predict the effect of fire on the structures, one
needs to understand physics of the fire growth in a
compartment as to how the fuel interacts with the flame
and its surroundings. This study explores these effects
and applies them to the common fuel configurations such
as pool and crib fires. The focus on the study is on the
fully-developed fires where all available fuel becomes
involved to the maximum extent and can potentially yield
the severest damage to the structural elements. A
single-zone compartment fire model is developed along
with a fuel mass loss rate model that accounts for the
thermal enhancement, oxygen-limiting feedback, and the
fuel type and configuration. A criterion for a one-zone,
fully-developed fire is established and validated with
experiments. An empirical correlation for mixing of
oxygen into the lower floor layer essential for the
modeling is also developed. An experimental program for
single-wall-vent compartment using wood crib and heptane
pool as fuels is carried out to validate the
mathematical model and explore a full range of phenomena
associated with fully developed fires: extinction,
oscillation, fire area shrinkage, and response of fuel
to thermal and oxygen effects. The simulation from the
model is able to capture these phenomena and shows good
agreement with the experiments. Some generalities of the
fuel mass loss rate and compartment gas temperature are
presented using the experimental results and the model
simulations. The developed model has a potential to give
burning time and temperature in a fire for any fuel,
scale and ventilation.
