基于水渗流和热对流传导耦合模型的冻土热量传输

发布时间：2018-10-25 19:08

【摘要】：冻土作为气候系统的一部分,是气候变化的重要指示因子。冻土的冻融过程,对地-气间的能量-水分传输、植被的生长状况和碳循环等具有重要的影响。采用数值模拟方法,分析了冻土冻融过程中伴随的热量传输,直观地呈现了能量和渗水在土壤中的传输过程。通过冻土热传导模型和流体流动模型耦合,采用有限元素法Comsol Multiphysics多物理场耦合软件系统,实现了速度与温度协同响应及对冻土冻融过程影响的模拟。模拟结果直观反映了在理想条件下,冻土冻融过程中温度场与速度场的变化:一方面,在土壤冻融过程中,温度场和速度场是相互作用的,并且其变化对土壤冻融过程起着至关重要的作用;另一方面,比较冻土的冻结过程与融化过程,冻结过程更难于发生且需要更加苛刻的条件。为此,可以间接地认为,永久冻土一旦退化便很难恢复,并且也将进一步加速环境的改变,从而形成恶性循环。
[Abstract]:As a part of climate system, frozen soil is an important indicator of climate change. The freezing and thawing process of frozen soil has an important influence on the energy and water transfer between soil and air, the growth of vegetation and the carbon cycle. The heat transfer in freezing and thawing process of frozen soil was analyzed by numerical simulation method, and the energy and water transfer process in soil was presented intuitively. By coupling the thermal conduction model of frozen soil with the fluid flow model, the Comsol Multiphysics multi-physical field coupling software system with finite element method is used to simulate the synergistic response of velocity and temperature and its influence on freezing and thawing process of frozen soil. The simulation results directly reflect the variation of temperature field and velocity field during freezing and thawing process of frozen soil under ideal conditions: on the one hand, the temperature field and velocity field interact with each other in the course of soil freezing and thawing. And its change plays an important role in the process of soil freezing and thawing. On the other hand, compared with the freezing and thawing process, the freezing process is more difficult to occur and requires more stringent conditions. For this reason, it can be concluded indirectly that permafrost, once degraded, is difficult to recover and will further accelerate environmental change, thus forming a vicious circle.
【作者单位】：西北师范大学地理与环境科学学院;国网甘肃省电力公司;
【基金】：国家自然科学基金项目(41461012)
【分类号】：P642.14

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