A model for numerical simulation of heat and water vapor exchange in multilayer textile packages with three-dimensional spacer fabric ventilation layer

Abstract

The work presents a structural computational model developed for investigation of heat and air—water vapor mass exchange between the multilayer textile packages and the human body. Each fabric layer is represented by a single element, characterized by its air and water vapor permeability, thermal resistance and heat capacity, as well as, water vapor absorption properties. While characteristics of each layer are obtained experimentally, the computational model enables the prediction of the variation in time of temperature and humidity in the gaps between each pair of adjacent layers. The finite element, which represents the forced ventilation layer made of three-dimensional textile material, is created and may be used as a structural element within the overall structural model of the textile package. The element equations are derived on the basis of ideal gas state equation. The results of the measured textile layers characteristics and the numerical data are presented. Though the condensation of water vapor was not considered in this model, the time point of initiation of sweating at given heat and water vapor generation rates could be predicted.

Prediction of air permeability coefficient and water-vapor resistance of 3D textile layer

“…In the first part air permeability coefficient was developed and validation was done basing on experimental data presented in (Zupin et al, 2012), theoretical investigations in (Pezzin, 2015). In the second part the water-vapor resistance coefficient has been found by performing simulation, which imitates the experimental process in accordance with ISO 11092:2014/LST EN 31902:2002 standard and theoretical investigations presented in (Barauskas & Abraitiene, 2011).…”

“…In the second part the water-vapor resistance R et coefficient of 3D textile was developed and validated on the results of the experimental research presented by Barauskas and Abraitiene (2011). The experimental value R et was obtained using The Sweating Guarded Hot Plate.…”

“…The air flow through the fabric is a physically coupled with heat and moisture transfer and other physical processes. The practically applicable models are multi-scale by virtue, as the internal physical processes and overall behavior of the 3D textile layer are considered in different space and time scales (Barauskas & Abraitiene, 2011).…”

Electrical properties of flat textile material as inhomegeneous and anisotropic structure

“…Modern textiles are used for the production of sportswear of high moisture repelling and regulating properties [1,2], in life parameter monitoring systems [3,4], as well as in electrotherapy, e.g. as textile electrodes [5][6][7].…”

Modeling of heterogeneous heat transfer in fabrics

“…Heat and moisture transfer have been also studied using numerical simulations for multilayer textile, 19 porous clothing assemblies. 20 In a mathematical model, 21,22 heat and moisture transfer in textiles are described with several assumptions for the moisture sorption process.…”