多孔介质有效导热系数的计算方法

高孔隙率多孔介质如泡沫陶瓷在新型多孔介质燃烧器技术中应用日益广泛,其重要传热特性参数--有效导热系数反映了两相流气、固相导热、对流和辐射的综合效应,对其研究尚非常缺乏.本文基于实验测定的温度分布,给出多孔介质有效导热系数的初始估值,用有限体积法求解二维控制方程,采用二维寻优搜索的办法,确定使测定点上测量与计算温度均方根误差为最小的径向与轴向有效导热系数,是一种逆计算方法.对球粒子颗粒床进行的有效性试验证明了方法的可行性.

Calculation of Effective Heat Conductivities in Highly Porous Media

Highly porous media such as ceramic foams find widely application in newly developed porous media burner . The flow and heat transfer in porous media are characterized through two phase problem and the investigation is very limited on effective heat conductivity which summarizes the conduction, dispersion and radiation in porous media. In the paper an inverse calculation program based on temperature measurements was presented to determine the effective heat conductivities. A finite volume method was used to solve 2-Dimensional governing equations by guessing the effective heat conductivities and meanwhile a 2-Dimensional searching program for effective heat conductivities was used. The best combination of radial and axial effective heat conductivity was obtained when a minimal root mean square error between the measured and simulated temperatures was reached. The validation was performed with packed beds.