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Smoke Movement in Corridors: Adding the Horizontal Momentum Equation to a Zone Model.


pdf icon Smoke Movement in Corridors: Adding the Horizontal Momentum Equation to a Zone Model. (467 K)
Jones, W. W.; Matsushita, T.; Baum, H. R.

U.S./Japan Government Cooperative Program on Natural Resources (UJNR). Fire Research and Safety. 12th Joint Panel Meeting. October 27-November 2, 1992, Tsukuba, Japan, Building Research Inst., Ibaraki, Japan Fire Research Inst., Tokyo, Japan, 42-54 pp, 1992.

Keywords:

fire safety; fire research; corridors; smoke movement; equations; zone models; heat transfer; experiments; computer models

Abstract:

The most common type of models utilized to study building fires are referred to as zone models. The motivation for using such models in preference to a complete implementation of the Navier Stokes equation is the great difficulty in obtaining solutions of the latter in realistic fire scenarios. One uses only a few elements, or zones, per compartment, and thus can apply the technique to many compartments. A more complete description of zone models is given elsewhere. This type of model works well in many cases. However, for long rooms or tall shafts, the basic tenet of the finite element concept as applied to fires is violated. The idea is that within an element, or zone, the gases are uniformly mixed, and there is no bulk velocity of the gas. To simulate smoke movement in large buildings, it is important to predict movement of the smoke front (nose) in the corridor or shaft. Although the ideas which we will discuss are also applicable to tall shafts, there will be differences in both the equations, and their implementation. This paper concentrates on the flow along a horizontal corridor.