Numerical models can explicitly characterize fluid flow and heat transfer processes in rock fractures including randomly distributed asperities and contacts and have been widely used to understand the behaviors of fluid flow and heat transfer in fractured rocks. The differences between three-dimensional and two-dimensional numerical models for single rock fractures were compared in terms of fluid flow and heat transfer behaviors and properties. Both the artificial fractures created by Brazilian tension method and the hypothetical fractures created by duplicating a fracture surface were considered. The results showed that hypothetical fractures and two-dimensional models cannot capture the channeling flow and the non-uniform thermal fronts in artificial fractures, but two-dimensional models can predict the similar streamlines and thermal fronts as hypothetical fractures. The relationship between heat transfer coefficient and flow rate in a single rock fracture can be described by a logarithmic function, and the heat transfer coefficients of two-dimensional and three-dimensional models can be well correlated by an empirical function of fracture surface areas. The comparison between three-dimensional and quasi-three-dimensional models of artificial fractures is also conducted. Both channeling flow and non-uniform thermal fronts from quasi-three-dimensional models became similar to the results of three-dimensional models with increasing numbers of computational elements.

数值模型可以明确地表征岩石裂缝中的流体流动和传热过程，包括随机分布的凹凸不平和接触，并已广泛用于理解裂缝岩石中的流体流动和传热行为。从流体流动和传热行为和性质方面比较了单个岩石裂缝的三维和二维数值模型之间的差异。既考虑了由巴西张力法产生的人工裂缝，也考虑了通过复制断裂面产生的假想裂缝。结果表明，假设裂缝和二维模型无法捕捉人工裂缝中的窜流和非均匀热锋，但是二维模型可以预测与假设裂缝相似的流线和热锋。单个岩石裂缝中传热系数与流速的关系可以用对数函数来描述，二维和三维模型的传热系数可以通过裂缝表面积的经验函数很好地关联起来。还进行了人工裂缝三维模型与准三维模型的比较。随着计算元素数量的增加，准三维模型的沟道流和非均匀热锋变得与三维模型的结果相似。单个岩石裂缝中传热系数与流速的关系可以用对数函数来描述，二维和三维模型的传热系数可以通过裂缝表面积的经验函数很好地关联起来。还进行了人工裂缝三维模型与准三维模型的比较。随着计算元素数量的增加，准三维模型的沟道流和非均匀热锋变得与三维模型的结果相似。单个岩石裂缝中传热系数与流速的关系可以用对数函数来描述，二维和三维模型的传热系数可以通过裂缝表面积的经验函数很好地关联起来。还进行了人工裂缝三维模型与准三维模型的比较。随着计算元素数量的增加，准三维模型的沟道流和非均匀热锋变得与三维模型的结果相似。还进行了人工裂缝三维模型与准三维模型的比较。随着计算元素数量的增加，准三维模型的沟道流和非均匀热锋变得与三维模型的结果相似。还进行了人工裂缝三维模型与准三维模型的比较。随着计算元素数量的增加，准三维模型的沟道流和非均匀热锋变得与三维模型的结果相似。