Mathematical Model Of Heat Transfer Within Multilayer Thermal Protective Clothing And Corresponding Optimal Parameter Determination

The mathematical study in thermal protective clothing aims to describe the thermo-dynamic laws within the thermal protective apparel-air layer-skin system by using mathe-matical models.It provides a reference for the functional design of the thermal protective apparel.At present,the research on thermal protective clothing mainly focuses on the new testing methods of thermal protective clothing,the prediction model of thermal protective performance of clothing,and the application of new materials in thermal protective clothing,etc.In this paper,the heat transfer process is fully explained by a multi-layer thermal pro-tective clothing-air layer-skin system.Based on the burn criteria,the prediction of burn time and the preliminary study of system parameters are given.At the same time,considering the heat transfer model of skin layer and burn evaluation model,a reasonable formulation of inverse problem is given.This paper is organized as follows:In chapter 1,we introduce the research background and significance of the thermal protective clothing,and briefly describe the research contents of this paper.In chapter 2,the heat transfer model in thermal clothing-air layer-skin system is estab-lished.The energy equations for the three layers of the clothing,the air gap,and the skin along with their boundary conditions are also given.Therefore heat transfer can be described by a nonlinear parabolic equation with variable coefficients.Furthermore,finite difference method is applied to prove the convergence rate of numerical scheme of the parabolic e-quation.Finally,the numerical results are compared with the existing model to verify the credibility of the model.In chapter 3,based on the system and combined with Henriques skin burns criteria,the maximum safety time to reach first,second and third degree burns are obtained by-experiment,which provide useful safety guidance for people who work in hot environment.At last,we analyze the influence of air gap and textile thickness on the performance of thermal protective clothing.In chapter 4,a reasonable definition of the inverse problem of thermal protective clothing is put forward:the optimal of thickness,porosity and thermal conductivity are determined under the premise of ensuring safety.Considering the law of skin burn,the inverse problem is come down to an optimization problem which is solved by genetic algorithm.The chapter 5,we summarize the content and highlights of this paper.The potential problems are also given.