Radiation and conduction heat transfer coupled with liquid water transfer, moisture sorption, and condensation in porous polymer materials

A new one-dimensional mathematical model to simulate the complex coupled heat and moisture transfer in porous polymer materials is presented. The new model takes into account effects of multiple involved processes such as radiation and conduction heat transfer, liquid capillary action, moisture sorption, and condensation. The technique of volume of fraction (VOF) is used to model the dynamic distribution of moisture in different phases, that is, vapor and liquid. The finite volume method (FVM) is used to develop the numerical computational scheme to solve the model. The temperature change on the fabric surface derived from the computational results of the model is compared with experimental measurements with reasonable agreement between the two. Further numerical simulations were carried out to investigate the complex interactions and coupling effects among the various heat and moisture-transfer processes involved. (C) 2003 Wiley Periodicals, Inc.