Fire Safety Science Digital Archive

A derivation is given for a simple algorithm which yields the quasisteady burning rate of a vertical panel of non-charring, non-melting material in an enclosure with stratification of temperature and oxygen concentration. The algorithm requires the solution of a transcendental equation. Among the thermophysical data which are needed, are the mean flame temperature and the height-dependent absorption coefficient, n (z). It is found from experiment that n(z) is well described for PMMA by a two parameter expression linear in l/z. Comparison with a transient experiment yields good agreement for the mass-loss race, over much of the range.