- Author
- Cooper, L. Y.
- Title
- Note on Calculating Flows Through Vertical Vents in Zone Fire Models Under Conditions of Arbitrary Cross-Vent Pressure Difference.
- Coporate
- National Institute of Standards and Technology, Gaithersburg, MD
- Journal
- Combustion Science and Technology, Vol. 64, No. 1-3, 1989,
- Keywords
- fire models | building fires | compartment fires | computer models | computer programs | algorithms | pressure differential | pressure effects | pressure vessels | zone models
- Abstract
- In typical compartment fire scenarios, ratios of cross-vent absolute pressures are close to 1. When such is the case, algorithms are available to predict the resulting cross-vent room-to-room flows. There are, however, important situations where this pressure condition does not prevail. For example, in fire scenarios involving relatively small penetrations in otherwise hermetically-sealed compartments of fire origin, cross-penetration pressure differences can be of the order of an atmosphere and pressure ratios, outside-to-inside, can be several tenths less than one. It is important for a versatile compartment fire model to have a capability of predicting vent flows for the entire range of possible cross-vent pressure conditions. This paper presents a unified analytic description of flows through uniform-width vertical vents connecting pairs of two-layer room fire environments under conditions of arbitrary cross-vent pressure difference. The algorithm presented is not significantly more complicated than previously-available algorithms which are restricted to low-pressure-difference cases.