Algorithm to Describe the Spread of a Wall Fire Under a Ceiling.
Algorithm to Describe the Spread of a Wall Fire Under a
Mitler, H. E.
NISTIR 5547; 53 p. November 1994.
Available from: National Technical Information Service
Order number: PB95-182259
algorithms; ceilings; ceiling fires; computer models;
fire growth; fire spread; pyrolysis rate; wall fires
After some discussion of wall fires, the effects that a
ceiling has on a wall fire are analyzed and discussed
qualitatively. There are two kinds of effects: first,
when the upper sill of the ventilating opening lies
below the ceiling (as is usual), a layer of hot gas is
trapped, which heats the walls by convection and
radiation; the heated ceiling also radiates to the
walls. A calculation which uses the wall-fire computer
model SPREAD is carried out to demonstrate how these
effects can be calculated now. Second, when the flame
impinges on the ceiling, it bifurcates and spreads
horizontally, rather than vertically. A simple
algorithm is presented which calculates the spread rate
of these horizontal flame extensions, as well as the
modified pyrolysis rate, due to the modified radiation