Influence of thickness and porosity on coupled heat and liquid moisture transfer in porous textiles

This paper focuses on a theoretical investigation of the coupling mechanism of heat transfer and liquid moisture diffusion in porous textiles using a mathematical model developed earlier. In the model, an equation describing liquid diffusion behavior is incorporated into an energy conservation equation and mass conservation equations of water vapor and liquid water transfer, which include vapor diffusion, evaporation, and sorption of moisture by fibers. A series of computations with systematic variations of fabric thickness and porosity is made to investigate the interactions between heat transfer and moisture transfer. Meanwhile, experiments are conducted to validate the model for fabrics with different degrees of hygroscopicity and thickness. Predictions of temperature changes during moisture transients are compared with experimental measurements, and good agreement is observed between the two, indicating that the model is satisfactory. Analysis of the computational and experimental results illustrates that the heat transfer process, which is influenced by fabric thickness and porosity, significantly impacts moisture transport processes.