在给出非饱和介质热能.水分传输的耦合质量控制方程和基于Fourier热传导定律的热能平衡方程的基础上,对热能传输及水分迁移的基本特征和机理进行了分析。其中,考虑了温度势、吸力势和重力势的耦合作用影响。给出有热源时控制方程的简化形式,并对半无限体自由表面作用平面热源条件下介质内非稳态温度场、体积含水率分布场进行数值积分求解。利用这些解答给出常热源强度和变热源强度两种情况下,温度场随时间的变化特征以及水分迁移的演化过程,并分析了重力项对计算结果的影响。
Coupled governing differential equations for both moisture transfer and heat flow are introduced. The approach adopted is based on the total potential for liquid flow being composed of the temperature potential, the elevation and the capillary potential. Besides, a simplified governing equation with heat source is given. The solutions of a semi-infinite unsaturated porous medium subjected to a plane heat source with variable strength with time on its free surface are studied. The numerical integral methods for calculating the unsteady temperature field, volumetric water content field are studied. The evolutions of temperature and moisture content are given under the conditions of constant and variable heat strengths; and the gravitational influences are also analyzed.