Modelling heat and moisture transfer in timber exposed to fire

The paper presents a simplified model for coupled heat and moisture transfer and charring behaviour of timber exposed to fire. A numerical method to calculate temperature, bound water, water vapour and pressure distribution over two dimensional domain in timber specimen exposed to fire was developed. In the model, a modified description of sorption for the temperatures above the boiling point is proposed. In addition, the model also accounts the char formation. Due to the non-linear system of governing equations describing coupled heat and moisture transport, together with the char formation, the solution is obtained numerically with the finite element method. Finally, the result from the numerical analysis are validated against experimental measurements.