Numerical Study of Opposed-Flow Flame Spread Over Charring Solids.
Numerical Study of Opposed-Flow Flame Spread Over
Park, W. C.; Atreya, A.; Baum, H. R.
E1 - Fire Research/Paper E03;
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. E1 - Fire
Research/Paper E03. March 20-23, 2005, Philadelphia, PA,
1-6 pp, 2005.
combustion; solids; charring; flame spread; equations;
thermal decomposition; kinetics; temperature; pressure;
Numerical calculations were performed on thermal
decomposition of charring solids undergoing opposed-flow
flame spread and the results are compared with
analytical models developed by Baum and Atreya. The
objective was to understand the effect of finite rate
kinetics on the temperature and pressure inside the
solid. The analytical solution, while exact, assumes
infinite kinetics, i.e. abrupt decomposition at a known
pyrolysis temperature. The numerical results using
finite and infinite rate kinetics showed good agreements
with the analytical model in terms of char depth and
temperature distribution. For the solution of the
pressure equation, numerical results showed good
agreements with analytical gas transport model from
surface to char/virgin solid interface. However, the
numerical result using finite kinetics implies that
pressurized region in real situation is larger than that
of infinite kinetics assumption. Numerical analysis
using infinite kinetics showed pressure
fluctuation due to lack of the information of the
interface shape inside a cell.