Progress in the Development of a Combustion Kinetics Database for Liquid Fuels.
Progress in the Development of a Combustion Kinetics
Database for Liquid Fuels.
(236 K)
Tsang, W.
A4 - Real Fuels/Paper A17;
Combustion Institute/Western States, Central States and
Eastern States. Fourth (4th) Joint Meeting of the U.S.
Sections. Hosted by The Eastern States Section of the
Combustion Institute and Drexel University. A4 - Real
Fuels/Paper A17. March 20-23, 2005, Philadelphia, PA,
1-6 pp, 2005.
Keywords:
combustion; liquid fuels; kinetics; databases; heptane;
soot; pyrolysis
Abstract:
We describe our progress in the development of chemical
kinetics databases for liquid fuels. The intention is to
create kinetics databases that can be used to simulate
all aspects of combustion across a wide range of
equivalence ratios. This paper will include some brief
comments on existing databases, a summary of current
work and a discussion of future directions. Liquid fuels
are complex mixtures containing hundreds of compounds.
There are however a limited number of classes. There is
general agreement that surrogate mixtures, with a
limited number of compounds, can reproduce much of the
combustion behavior of real fuels. The largest component
in liquid hydrocarbon fuels are the linear alkanes and
we have concentrated our work on this type of compound.
The discussion will cover work on the development of a
database for the cracking of heptane to form the small
olefins and dienes that can be used as inputs to
PAH/soot models.Primary emphasis has been on the
unimolecular reactions that break the larger organic
radicals to smaller components used in soot models. Rate
constants on the isomerization and breakdown of all
alkyl radicals from C4 to C7 and 1-olefinyl radicals
from C4 to C6 have been determined. Recent work has
dealt with the chemically activated decomposition of
alkyl radicals from H addition to the olefins. These are
competitive with the products from hydrogen abstract and
will favor olefin as opposed to diolefin yields. The
discrepancy between low and high temperature results on
isomerization of alkyl radical has been assigned to
tunneling effects. Work on the elementary reactions for
butylbenzene decomposition was completed. Problems and
extensions of this work to more general situation will
be discussed.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899