Modeling of heat and moisture transport by periodic ventilation of thin cotton fibrous media

In walking conditions, the air spacing between the fabric layer of a porous clothing system and the human skin changes with the walking frequency. This change will cause air penetration in and out of the clothing system depending on the fabric air permeability. The air passing through the fabric can considerably reduce the heat and moisture transfer resistance of the clothing system and its suitability for a given thermal environment. In this work, the coupled convection heat and moisture exchange within the clothing system subject to sinusoidal air layer thickness variation about a fixed mean is experimentally investigated and theoretically modeled to predict the periodic fabric regain, the fabric temperature and the transient conditions of the air layer located between the fabric and the skin.