摘要
本文在建立冻土水热耦合迁移的数学模型基础上，采用全隐式有限差分格式并用线性化迭代方法求解。边界条件处理采用半控制容积法，时间步长根据迭代情况自动调节，求解过程中为防止振荡过大采用松驰迭代等措施。通过计算与实验结果对比，取得较好效果，表明采用的数学模型及数值计算方法可靠。用此模型模拟了非实验状态下（历时３０ｄ及表面温度降至－２０°Ｃ）的土壤冻结过程。模拟显示温度分布随冻结历时的加长而变缓，最后趋于线性分布，随上、下表面温差的加大而变陡；水分分布基本形状并不随时间及上、下表面温差而变，只是冻深及上迁水量随历时加长、温差加大而增大。
Based on the mathematical model for solving the problem of coupled moisture and heat transfer during soil freezing, the numerical calculation was carried out in this paper. An implicit finite difference scheme is used to solve the model. An experiment was conducted to verify the model. The calculated results agreed well with the observed ones, which showed that the model was reliable. Using this model, Simulations on other conditions (freezing during 30d, etc.)were conducted.
基金
日本文部省资助
关键词
土壤冻结
数值模拟
土壤水分
水热运动
soil freezing, coupled moisture and heat transfer, numerical simulation, implicit finite difference
