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Users' Guide to BREAK1, The Berkeley Algorithm for Breaking Window Glass in a Compartment Fire.


pdf icon Users' Guide to BREAK1, The Berkeley Algorithm for Breaking Window Glass in a Compartment Fire. (1055 K)
Joshi, A. A.; Pagni, P. J.

NIST GCR 91-596; 27 p. October 1991.

Sponsor:

National Institute of Standards and Technology, Gaithersburg, MD

Available from:

National Technical Information Service
Order number: PB92-112556

Keywords:

computer models; fire models; glass; mathematical models; radiation; thermal stresses; vents; thermal conductivity; thermal diffusivity

Abstract:

This is an instructional manual for the computer program BREAK1, the Berkeley Alogorithm for Breaking Window Glass in a Compartment Fire, version 1.0. The thermal response of window glass exposed to a compartment fire and its time to breakage are calculated. The following glass properties, treated here as constant, are required as input: thermal conductivity, thermal diffusivity, absorption length, breaking stress, Young's modulus, coefficient of linear thermal expansion and emissivity. In addition, the ambient temperature, the hot layer temperature, heat transfer coefficients and emissivities and the direct flame radiation histories are needed as input. The window geometry is also required. The output describes the evolution of the window temperature field, T(x,t), where x is the direction normal to the glass pane, culminating in the window breakage time. This manual contains a summary of the mathematical model, sample thermophysical and mechanical data tables, some worked examples and advice on using the program.