Heat transfer mechanisms and models for a gypsum board exposed to fire

In this paper, the effects of vapour transport and condensation are included to improve the simulations. It is shown that, contrary to other findings in the literature, vapour transport without condensation has virtually no influence on the heat transfer. However, when including condensation, a mechanism similar to a heat pipe is able to reproduce the observed temperature plateau. To explain some contradictory results encountered in the literature, a large effort is devoted to rigorous mathematical formulations and to realistic material parameters. It is shown that some effects attributed to vapour transport in the literature are in fact due to inconsistent mathematical formulations.