分形理论在耐火纤维材料的导热特性研究中的应用

Fractional Theory Applied in Thermal Conductivity Characteristics Investigation of Refractory Fiber Material

运用分形理论对多孔介质的几何结构进行描述,建立了耐火纤维材料的导热分形模型,并据此模型推导出其有效导热系数计算式;公式表明,耐火纤维材料的导热过程除了与气、固两相的物性和温度有关外,还与其体积分率以及孔隙分形维数有关。通过应用此计算式进行计算,得出了耐火纤维材料的有效导热系数计算值,而且计算结果与实验数据吻合得比较好,表明该导热模型计算式具有较高的表达精度。

Using fractional techniques,the geometric structure of porous media is described and a fractional heat conductivity model is established. Then on the grounds of the model, the expression of effective thermal conductivity of refractory fiber material is given out. The expression shows that heat conduction process of refractory fiber material depends on physical property parameter of gaseous phase and solid phase,temperature and the ratio of fiber of refractory fiber material to the volume of the whole as well as the pore fractional dimensions. By this expression,the value of effective thermal conductivity of refractory fiber material is calculated. It is found that the calculations value is in line with the experimental data. The results indicate that the expression of heat conductivity model has high accuracy.