Calculating Combined Buoyancy- and Pressure-Driven Flow Through a Shallow, Horizontal, Circular Vent; Application to Problem of Steady Burning in a Ceiling-Vented Enclosure.
Calculating Combined Buoyancy- and Pressure-Driven Flow
Through a Shallow, Horizontal, Circular Vent;
Application to Problem of Steady Burning in a
Cooper, L. Y.
National Institute of Standards and Technology (NIST)
and Society of Fire Protection Engineers (SFPE).
International Conference on Fire Research and
Engineering (ICFRE). Proceedings. September 10-15,
1995, Orlando, FL, SFPE, Boston, MA, Lund, D. P.;
Angell, E. A., Editors, 321-326 pp, 1995 AND European
Symposium on Fire Safety Science, First (1st).
ABSTRACTS. Proceedings. Session II. Fire Dynamics 2.
ETH Institute for Structural Engineering. August 21-23,
1995, Zurich, Switzerland, II-17/99-99 pp, 1995.
fire research; vents; buoyancy; pressure; ceilings;
enclosures; algorithms; equations; energy release rate;
ships; wood; ceiling vents; oxygen concentration
A model was developed previously for calculating
combined buoyancy- and pressure-driven (i.e., forced)
flow through a shallow, circular, horizontal vent where
the vent-connected spaces are filled with fluids of
different density in an unstable configuration (density
of the top fluid is larger than that of the bottom). In
this paper the model equations are summarized and then
applied to the problem of steady burning in a
ceiling-vented enclosure where normal atmospheric
conditions characterize the upper space environment.
Such fire scenarios are seen to involve a
zero-to-relatively-moderate cross-vent pressure
difference and bi-directional exchange flow between the
enclosure and the upper space. A general solution to
the problem is obtained. This relates the rate of
energy release of the fire to the area of the vent and
to the temperature and oxygen concentration of the upper
portion of the enclosure environment. The solution is
seen to be consistent with previously-published data
involving ceiling-vented fire scenarios.