A model for multiphase moisture and heat transport below and above the saturation point of deformable and swelling wood fibers – I: Mass transport

A thermodynamically consistent model for heat and mass transfer in deformable wood fibers is developed. The hybrid mixture theory used to the material as a of three phases, consisting solid, liquid gas phase. solid phase consists dry bound water constituents, whereas has air vapor constituents. Emphasis put on flow exchange moisture both below above saturation point fibers. Generalized forms Fick’s, Darcy’s Fourier’s laws are derived, chemical potential driving force flow. Mass due sorption evaporation/condensation processes implemented model, where hysteretic properties within hygroscopic range described using Frandsen’s hysteresis model. Moisture induced swelling/shrinkage included porosity can vary. large strain setting formulated general orthotropy adopted mechanical deformations. To show performance resulting it finite element method framework simulate transport dynamics sample subjected drying from an over-hygroscopic state.