A multi - parameter random generation - growth methods,quartet structure set( QSGS) ,was introduced for replicating the microscopic stucture of the SiO2 porous insulation materials. The inroduction of two - dimensional nine speed multiphase incompressible Lattice - Boltzmann thermal model makes the the calculation of the micoscale heat transfer easy in porous materials with complex boundary. The program implementation process of bothe replicating the structure and the Lattice - Boltzmann heat transfer a-nalysis was developed. Then the complete numericl analysis of two - dimensional heat transfer in porous materials was carried out. The results indicate that a larger pore size could lead to a smaller effective thermal conductivity when the Knudsen number was less than 10 -1and in the same porosity. And as the porosity be smaller, the effective thermal conductivity increasd significantly. To increase the proportion of gas heat transfer is an effective way to enhance the insultion properties of the insulation materials. Differences in skeletion stuctuer were significantly for the effective thermal conductivity of the SiO2 porous insulation materials.%采用四参数随机生成法构造了SiO2多孔绝热材料微观结构,引入二维九速度不可压格子多相Lattice-Boltzmann热模型,该模型能够方便的计算具有复杂边界的多孔材料微尺度传热问题,给出了从结构构造模拟到具体的Lattice-Boltzmann传热分析的程序实现流程,进行了完整的二维多孔绝热材料导热过程的数值分析.结果表明Knudsen数小于10-1时,相同孔隙率下孔径越大,有效导热系数越低.随着孔隙率的减小,有效导热系数明显增加,增加气相导热比重是增强该绝热材料绝热性能的有效途径.骨架结构对SiO2多孔绝热材料有效导热系数的影响显著.
展开▼
