Several Inverse Problems Of Textile Material Design Based On Dynamic Heat-moisture Transfer

As the necessaries of life, textile material act on covering body and keeping warm.As living standards raise, people demand more on textile material and productionengineering, which must satisfy human heat-moisture comfort, tactile comfort, visualand sensory comfort. In the tradition of production engineering, the major methods oftextile material design depend on life experience or scientific experiment. In order toguide the textile material design in theory, we provide mathematical formulation ofinverse problems of textile material determination （IPTMD）.This thesis presents the inverse problems of textile material porosity design insingle layer（IPTPD） and multi-layers textile material thickness determination（IPTTD）based on dynamic heat-moisture transfer.Based on "human body-clothing-environment", the direct problem corresponding toIPTMD is that the heat-moisture transfer model is built for studying the phenomenonof heat-moisture transfer with different textile material in different environment. Itdisplays the influence and rule of the textile material’s thickness, porosity,heat-conductive and diffusing coefficient on heat-moisture transfer.After considering the physical phenomenon such as heat diffusing, heat conduction,radiation and condensation, we attribute the dynamical model to complex non-linearcoupled partial differential equations in the IPTPD. To prove the existence-uniquenesssolution, the Banach’s fixed theory is employed, which can display the uniqueness ofchange of the temperature and the vapor water concentration and provide the theoryevidence for studying the inverse problem.In the IPTTD, because the temperature gradient and the vapor water concentrationgradient are not continue in the interface of the two different textile material, thederivative of solution is not continue. We need to choose the solution space fitting theapplied background to prove the existence-uniqueness of solution.To obtain the numerical solution of IPTPD, the finite differential method is adopted.We do numerical simulation in different environment and several textile materialtypes for studying the change of the relative humidity in the micro climate. The result display that the human heat-moisture comfort depend on the environment and textilematerial.Generally speaking, under the condition of the human body heat-moisture comfort,IPTMD mainly study the optimal physical parameters and structural parameters of thethickness, porosity, heat-conductive of textile material in different environment （theenvironment temperature and humidity are different）. This paper presents the mathformulation, numerical algorithm and numerical simulation of the IPTPD and theIPTTD.The method and theory of inverse problem are employed to attribute the IPTPD toobjective function of one variable Jα （ε）. Using L-curve method, the optimalregularized parameter of objective function is determined. The Particle SwarmOptimization （PSO） method is applied to search the solution of the objective function.The solution of the IPTPD is not the traditional classical solution, but the optimalsolution satisfying human body heat-moisture comfort.The IPTTD is attributed to search the minimum problem of objective function oftwo variablesJ α （L1, L2）, whereL1is the thickness of inner porous batting andL2is the thickness of outer porous batting. In the applied background, as thinking aboutthe thickness of clothing, the price of textile material and so on, we add the punishitem α|L₁-L₂-Lmax, whereLm axstands the maximum thickness of material textile.As well as IPTPD, L-curve method is adopted to decide the optimal regularizedparameter. Because two variables are both decided, alternating direction method istaken to obtain the solution.The result of numerical simulation presents that the math method of IPTPD andIPTTD are right and the algorithm is validation. The two inverse problems fit theactual requirement of life and provide the scientific explain for theory design oftextile material.