Heat and sweat transport through clothing assemblies with phase changes, condensation/evaporation and absorption

The paper is concerned with the heat and sweat transport in porous textile media with complex phase changes, which is described as a non-isothermal, multi-phase and multicomponent fluid flow and governed by a nonlinear, degenerate and strongly coupled parabolic system. The phase change, condensation/evaporation and fibre absorption, play an important role in the design of functional clothing. In this paper, we present some more precise formulations on condensation/evaporation, fibre absorption and heat capacity to maintain the physical conservation of mass and energy. A typical clothing assembly with a hydrophobic batting material and two different types of cover is investigated numerically. Numerical results show that for the hydrophobic material, the evaporation and condensation zones arise simultaneously in the batting area and that the proposed formulations are more realistic to describe the phase change. Existence and uniqueness of a classical positive solution for the incompressible model are also proved.