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光滑粒子流体动力学(SPH)作为一种拉格朗日型无网格粒子方法,已经成功地应用于多种类型耦合问题的求解。基于SPH方法探索求解二维求解域内含有圆形局部热源的水热耦合问题,其中揭示了程序前处理阶段已有粒子布置方案存在的不足。针对所要求解的具体问题,使用一种新的粒子布置方案以弥补数值计算过程中的精度损失,该粒子布置方案中径向粒子间距严格相等,环向间距大致等于径向粒子间距。通过对水热耦合方程数学特性的分析,表明了SPH算法可以用于此类耦合问题的数值模拟。最后,基于SPH算法自行编制的程序对一种非饱和土介质内含有局部热源的水热耦合问题进行数值模拟,对非饱和土介质中热能传输以及水分迁移的规律进行了分析。
As a Lagrange-type meshless particle method, Smooth Particle Hydrodynamics (SPH) has been successfully applied to solve many kinds of coupling problems. Based on the SPH method, the problem of water-heat coupling with two circular local heat sources in a two-dimensional solution is explored, which reveals the shortcomings of existing particle arrangement schemes in preprocessing stage. Aiming at the specific problem to be solved, a new particle arrangement scheme is used to compensate for the loss of accuracy in the numerical calculation. In this particle arrangement, the radial particle spacing is strictly equal and the circumferential spacing is approximately equal to the radial particle spacing. Through the analysis of the mathematical properties of the hydrothermal coupling equation, it is shown that the SPH algorithm can be used for the numerical simulation of such coupling problems. Finally, based on the program compiled by SPH algorithm, a numerical simulation of the hydrothermal coupling problem in a unsaturated soil with local heat source is carried out. The laws of heat transfer and moisture migration in unsaturated soil are analyzed.