多孔介质有效热导率的一种新模型  

A New Fractal Model for the Effective Thermal Conductivity of Porous Media

作　　者：王世芳[1] 吴涛[2] 

机构地区：[1]湖北第二师范学院物理与机电工程学院,武汉430205 [2]武汉工程大学理学院,武汉430074

出　　处：《工程热物理学报》2016年第12期2626-2630,共5页Journal of Engineering Thermophysics

基　　金：国家自然科学基金资助项目(No.11402081)

摘　　要：多孔介质的有效热导率是各种保温材料、石油开采、土壤科学等工程应用领域的一个重要参数。本文利用分形理论及与热电模拟方法,提出了由一束平行正弦形收缩性弯曲毛细管组成的多孔介质有效热导率的一种新分形模型。结果表明,多孔介质有效热导率是固相热导率、气相热导率、多孔介质孔隙率、横截面积、最大平均孔隙半径、幅度波动因子的函数;多孔介质有效热导率分形模型理论预测值与实验测量数据进行对比,结果显示吻合很好;同时还分析了幅度波动因子及分形维数对多孔介质有效热导率的影响。The effective thermal conductivity of porous media is a key parameter for many engineering applications such as various thermal insulation material,oil exploitation,soil science and so on.Based on the fractal theory and the thermal-electrical analogy method,a new fractal model for the effective thermal conductivity of porous media is presented,in which porous media are assumed to be composed of a bundle of tortuous sinusoidal capillaries with constrictions and expansions.Results show that the effective thermal conductivity expression is a function of the effective thermal conductivity of solid phase and gas phase,porosity,the total cross-sectional area,the maximum average radius and the fluctuation amplitude factor.To test the validity of the present effective thermal conductivity model,the theoretical predictions from our thermal conductivity model are compared with the available experimental data,and a good agreement between them is found.Furthermore,the influences of fluctuation amplitude factor and fractal dimensions on the effective thermal conductivity are also analyzed.

关 键 词：热导率 多孔介质 分形理论 热电模拟 

分 类 号：O357.3[理学—流体力学]