Numerical Simulation Of Heat And Moisture Transfer Through Multi-layer Textile

The heat and moisture transfer of porous media is a common phenomenon in civil engineering,energy storage and energy saving,and functional clothing design.The theory of multi field coupling behavior of the porous medium has a wide range of applications.Its research has gained wide attention and rapid development,has the interest also applied to various fields,such as heat and mass transfer,soil drying,buildings,and fiber insulation materials.Studying the coupling rule of heat and mass transfer in porous media can not only further understand the structure and physical and chemical properties of porous media,but also have wide practical value.Though considerable efforts have been made in the past,due to the complexity of temperature and the influence of phase transformation,the complexity of transient heat and moisture coupling process still has great room for development.Nowadays,people are getting more and more comfortable and functional.The comfort of clothing depends largely on the heat and wet feeling of people after dressing,and the functionality of clothing depends largely on its heat and humidity characteristics.As a traditional industry,clothing and innovation are the hot and direction of the research,and it is also the inevitable choice in the development of clothing.Under the condition of dressing,the fabric is one of the unsaturated porous media.The theory of heat and mass transfer in porous media is applied to the field of clothing.It is still a hot topic for scholars and developers to study the heat and moisture transfer process of environment,clothing and human body micro system.Lightweight down garment is a new down garment variety that has springing up in recent years.Because of its lightweight texture,soft handle,fashionable style and easy storage,it is popular among many consumers.Down jacket is a multi-layer fabric structure consisting of inner and outer fabrics and fillers.The selection and combination of materials will have an important influence on the thermal and moisture comfort of clothing.Based on the thermal and moisture comfort performance of multi-layer porous fabrics,the interaction between light down jacket under low temperature and partial humidity is studied in this paper.In this paper,the heat and moisture transfer process in porous textile medium with complex phase transformation is studied.It is described as a non-isothermal,multiphase and multi-component fluid flow controlled by a nonlinear and strongly coupled parabolic equation.This paper chooses thin jacket type commonly used high density and no bile downptoofs 90% white feather as experimental materials.Firstly,the basic physical parameters of fabric and wadding material for testing.Considering the various physical phenomena of multilayer fabric heat and moisture coupling process,we put forward the basic assumptions,set initial conditions and boundary conditions according to the physical and mental phenomena of multilayer fabric heat and moisture coupling.Then using the finite volume method to discrete equation and intermediate variables.And then use Mat lab software for numerical solution,analytic solutions are compared with the experimental results,verify the rationality of the model.Finally use the equations to simulate the multilayer fabric internal temperature and water vapor concentration distribution when there are some changes in the external environment.