Investigating the effective thermal conductivity of moist fibrous fabric based on Parallel-Series model: A consideration of material's swelling effect

Abstract

The aim of this work reported in the paper is to investigate the influence of moisture content on the effective thermal conductivity (ETC) of non-hygroscopic Polyethylene terephthalate (PET) and hygroscopic Viscose (VC) fabrics using Parallel-Series (P-S) thermal-electrical analogy method and TPS measurement. An equivalent porosity for hygroscopic fabric was first proposed to preserve the validity of the P-S model. The equivalent porosity is characterized by reasonably eliminating the absorbed moisture effects partly, which is embodied in enhancing heat conduction, endothermic reaction and swelling. Calculated values of the effective thermal conductivity of the two kinds of fabrics had been compared with experimental measurements. Results show that the P-S model incorporated with equivalent porosity is found to yield higher prediction accuracy than that of P-S model with parent porosity. The calibrated model can also provide a robust tool for predicting the global effective thermal conductivity of moist hygroscopic fibrous porous media.