Clothing Air Layer Heat And Moisture Transfer Mechanism

Based on the general review and analysis of the research on the heat and moisture comfort through clothing , we find that there hasn't been a comparatively complete theoretical model and a comparatively systematic simulating method . So , centralizing the garment air, a new mechanism model of heat and moisture transfer is proposed in this thesis.In this model , we regard the garment air layer(including the micro-climate)as the research object. According to the concept of characteristic unite of volume , we applied the continuum media approach and the basic laws about heat , mass and momentum transfer. At the same time , much phenomenon are taken into account, such as the phase transformation , the absortion of moisture , the desorption , the convertion of air and the penetration , and so on . Then a new physical and mathematical model is established , in which the laws about the change of temperature field, wet concentration field , gas phase field and velocity field in the garment air layer, is well reflected . Accordingly , another mathematical model , which is about the conservation equation of quality , the motion equation , the conservation equation of energy and the overall pressure distribution , is also abtained and we also made an analysis about the main parameters in this model.During the process of parameter analysis, we take three main steps . First, using the complete implicit difference method , one method of finite difference , we make an analysis of variance as to the mathematical model of heat and moisture transfer through clothing , the boundary trasfer equation , the boundary equation of velocity distribution , wet distribution and temperature distribution , including their inner and outer boundary condition are transformed into node equations . Then, through numerical calculating, we get the value of the wet concentration, the velocity and the temperature at the node point of the grid unite . Finally , we use Matlab to design a programe and through it make the numerical calculation.In addition, by virtue of the computer programe , this new model can also be used to simulate the heat and moisture transfer process in micro-climate under varied boundary condition of humen body , clothing and environment. And through it, we analyzed the temperature field , the wet concentration field and the overall pressure field . The rules about how the air affects the heat and wet comfort of garment is abtained . Besides the easily accessible experiment dates , we can also acquire the instant distribution oftemperature field , the vapour pressure field inside the garment air . And the instant flux of heat and mass can also be got.