中文摘要：

为了研究高孔隙率通孔金属泡沫中的热传导特性及预测有效导热系数,发展了一种新的全解析有效导热系数模型.该模型通过建立更真实的十四面体三维结构作为代表单元,解析求解代表单元内稳态傅里叶热传导方程获得通孔泡沫铝的有效导热系数.该模型不合任何拟合或经验参数,有效导热系数与孔隙率之间具有简单的线性关系,且比例系数阐释了热曲折率的大小.高孔隙率下,模型预测与实验测量和文献数据吻合良好.研究结果表明：对于具有大导热系数比的实心杆与流体相（如充满空气的泡沫铝）,流体相的传热可忽略不计,热量沿着曲折金属杆的一维传导占主导地位.在忽略自然对流和辐射传热时,泡沫铝有效导热系数基本不受孔密度及杆截面形状的影响.在所研究的温度范围内,泡沫铝有效导热系数可视为常数.

英文摘要：

To demonstrate a totally analytic model of effective thermal conductivity in high porosity open-cell metallic foams, a 3D tetrakaidecahedron configuration is selected as the representative unit cell for the metal foam. By solving 1D steady-state Fourier＇s equation for the representative volume, a purely analytic model without requiring any fitting or empirical coefficient is obtained. Coinciding well with the present measurements and experimental data from literature, this model suggests a linear dependence of effective thermal conductivity upon porosity, where the proportionality coefficient is the reciprocal of thermal tortuosity. The heat transfer in fluid phase is negligible due to large thermal conductivity ratio between solid ligaments and fluid phase （e. g. , air-saturating A1 foam）, 1D heat conduction along the tortuous ligaments thus dominates. Neglecting natural convection and radiation of thermal energy, the topological parameters, such as pore density （PPI） and ligament cross-sectional shape, exert little influenceon effective thermal conductivity. Furthermore, the effective conductivity remains constant within the experimental temperature range.