Calculating Flows Through Vertical Vents in Zone Fire Models Under Conditions of Arbitrary Cross-Vent Pressure Difference.

Published

May 1, 1988

Author(s)

Leonard Y. Cooper

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. It is important for a versatile compartment fire model have a capability of predicting vent flows for the entire range of possible cross-vent pressure conditions. This paper develops a unified analytic description for flows through vertical vents between pairs of two-layer room fire environments under conditions of arbitrary cross-vent pressure difference. The analysis, which takes advantage of generally useful modeling approximations, leads to a concise result which is not significantly more complicated than the result for simple, low-pressure-difference cases.

Citation

NBSIR 88-3732; 16

Pub Type

Others

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Keywords

fire models, building fires, compartment fires, computer models, computer programs, algorithms, pressure differential, pressure effects, pressure vessels, zone models

Citation

Cooper, L. (1988), Calculating Flows Through Vertical Vents in Zone Fire Models Under Conditions of Arbitrary Cross-Vent Pressure Difference., NBSIR 88-3732; 16, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=916843 (Accessed April 25, 2024)