热防护服装热传递数学建模及参数决定反问题

发布时间：2018-04-29 12:40

本文选题：热传递模型 + 安全性　；参考：《浙江理工大学》2017年硕士论文

【摘要】：运用数学或科学的方法研究热防护服装,旨在揭示热防护织物内部的热传递规律,为热防护服装的研发提供科学参考.热防护服装是应用最广泛的特种防护服装,目前关于更多热防护服装的设计集中在热防护性能测定、建立热防护服装内部传热模型、发展测定热防护性能的试验方法和实验装置和热防护服装舒适性评价等.合理地评价热防护服装的热防护性能对减少工作人员皮肤损伤具有重要意义.本文主要是对单层热防护服装热传递模型进行介绍,此外,我们通过对空气层和皮肤层的热传递数学模型及烧伤评价模型等的研究,结合烧伤准则提出了相关反问题.主要内容如下:第一章,介绍了热防护服装的研究背景和意义、国内外的研究现状,并且对本文主要内容和创新点进行了简要描述.第二章,介绍了热防护服装的热传递模型建立过程,研究了热防护织物在高温条件下热传导和热辐射传热机制的作用,引入了用实验法确定的织物Nomex的热传导系数、单位体积热容量系数随温度变化的经验公式,分析了织物与热源之间的热交换边界条件,最终确立了热防护织物的热传递模型,并且给出了数值分析和计算,通过数值结果和已有实验论证的模型作比较,证明了提出模型的合理性.第三章,在前面提出的热防护服装的热传递数学模型的基础上,结合空气层模型和皮肤模型,构成“热防护服装-空气-皮肤”完整的系统.这部分完整的给出了织物和皮肤之间空气层的模型以及表皮、真皮、皮下组织的热传递数学模型,并且对整个系统进行了数值离散,给出了正问题的计算结果.第四章,对于热防护服装而言,设计反问题的目标就是在尽量减少甚至不产生热损伤的情况下,决定系统的相关参数.基于第三章“热防护服装-空气层-环境”系统正问题模型的分析,我们将目标点设在基底层(表皮和真皮的接触面),以保证基底层未达到二级烧伤为目标,我们给出了热防护服设计反问题的一种合理提法,并数值求解了相应的反问题.第五章,介绍了在反演一类抛物型方程初始值的过程中,我们为了求解极小化泛函,结合伴随变分引入一种变形TV正则化的方法.文中对极小目标泛函的存在唯一性和稳定性进行了理论证明和分析,并通过具体算例说明了方法的有效性.第六章,我们对本文的创新点等进行了总结,并提出一些可继续研究的方向。
[Abstract]:The purpose of this paper is to study thermal protective clothing by mathematical or scientific methods in order to reveal the internal heat transfer law of thermal protective fabrics and to provide scientific reference for the research and development of thermal protective clothing. Thermal protective clothing is the most widely used special protective clothing. At present, the design of more thermal protective clothing focuses on the measurement of thermal protection performance and the establishment of internal heat transfer model of thermal protective clothing. To develop test methods and equipment for measuring thermal protective properties and evaluation of thermal protective clothing comfort. It is important to evaluate the thermal protection performance of thermal protective clothing reasonably to reduce the skin injury of staff. In this paper, the heat transfer model of single layer thermal protective clothing is introduced. In addition, through the study of heat transfer mathematical model and burn evaluation model of air layer and skin layer, and combined with the burn criterion, the related inverse problems are put forward. The main contents are as follows: the first chapter introduces the research background and significance of thermal protective clothing, the current research situation at home and abroad, and briefly describes the main content and innovation of this paper. In the second chapter, the process of establishing heat transfer model of thermal protective clothing is introduced. The function of heat conduction and heat radiation heat transfer mechanism of thermal protective fabric under high temperature is studied, and the heat conduction coefficient of fabric Nomex determined by experiment method is introduced. The empirical formula of the change of unit volume heat capacity coefficient with temperature is given. The boundary conditions of heat exchange between fabric and heat source are analyzed. Finally, the heat transfer model of thermal protective fabric is established, and the numerical analysis and calculation are given. The rationality of the proposed model is proved by comparing the numerical results with the existing models. In the third chapter, based on the mathematical model of heat transfer of thermal protective clothing, combined with air layer model and skin model, a complete system of "thermal protective clothing-air-skin" is constructed. In this part, the model of air layer between fabric and skin and the mathematical model of heat transfer between skin, skin and epidermis are given, and the whole system is discretized numerically, and the calculation results of positive problem are given. In the fourth chapter, for thermal protective clothing, the goal of inverse design problem is to determine the relevant parameters of the system under the condition that the thermal damage is minimized or even avoided. Based on the analysis of the model of "Thermal Protective clothing-Air layer-Environment" system in Chapter 3, we set the target point at the base layer (the contact surface of epidermis and dermis) in order to ensure that the base layer does not reach the secondary burn. A reasonable formulation of the inverse problem in the design of thermal protective clothing is given, and the corresponding inverse problem is solved numerically. In chapter 5, we introduce a new method of TV regularization in order to solve the minimization functional in the process of inversion of initial values of a class of parabolic equations. In this paper, the existence, uniqueness and stability of the minimal objective functional are theoretically proved and analyzed, and the effectiveness of the method is illustrated by an example. In the sixth chapter, we summarize the innovation of this paper and put forward some directions for further study.
【学位授予单位】：浙江理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TS941.731.3

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