发表机构
University of Bologna; Stanford University; Univ Rennes, CNRS, Géosciences Rennes, UMR 6118（博洛尼亚大学; 斯坦福大学; 雷恩大学、法国国家科学研究中心、雷恩地球科学实验室）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究以热锋等为诊断指标，采用随机半解析通道模型，揭示非牛顿流体流变对裂缝-基质热输运中水力选择的影响，区分了流变控制与基质控制热输运的参考极限。
AI 中文摘要
地质裂缝具有非均匀的开度场，使流动沿优势路径局部化，导致流体-基质接触时间不均匀。热输运由通道化平流与岩石基质的传导交换耦合而成。对于非牛顿流体，这种耦合具有本构依赖性：剪切稀化使开度-通量映射偏向更大开度，而屈服应力会抑制低于启动阈值的流动。本研究采用热锋推进、纵向扩展和出口突破作为诊断指标，研究裂缝-基质热输运中流变控制的水力选择。随机半解析通道模型将开度类别表示为具有本构确定通量的平行路径，通过半无限基质的通道尺度平流-传导解的通量加权叠加得到热响应，这种分离可独立分析后期标度和响应振幅。流变不仅通过平均速度影响可观测的扩展，还通过高阶通量加权开度矩（决定持续通道间方差的振幅）产生影响。基质扩散决定突破曲线和锋矩的后期标度，而开度变异性和流变控制振幅、交叉行为及通道间扩展。全局敏感性分析显示，剪切稀化控制通量重新加权，屈服应力控制水力可达性和保留流动。归一化为固定通量加权平均速度后，开度变异性和流指数共同重新分配载热通量并改变停留时间谱。该模型定义了一个可解释的参考极限，用于区分流变控制的水力选择与基质控制的热输运。
英文摘要
Geological fractures exhibit heterogeneous aperture fields that localize flow along preferential pathways and produce nonuniform fluid-matrix contact times. Heat transport combines channelized advection with conductive matrix exchange. For non-Newtonian fluids, shear thinning biases the aperture-to-flux mapping toward larger apertures, while yield stress suppresses flow below the mobilization threshold. A stochastic semi-analytical model represents aperture classes as parallel pathways with constitutive fluxes and superposes their channel-scale advection-conduction solutions for a semi-infinite matrix. Matrix diffusion sets the late-time scalings of breakthrough curves and front moments, while aperture variability and rheology control their amplitudes and crossover. Rheology affects spreading through high-order flux-weighted aperture moments that determine persistent inter-channel variance. For monomial flux laws, the reduced late-time amplitudes collapse onto a single similarity variable, so shear thinning acts as amplified effective aperture variability. Global sensitivity analysis attributes flux reweighting to shear thinning and hydraulic accessibility to yield stress. Two-dimensional simulations verify the construction for Newtonian and power-law flow. A connected rough-field comparison at low aperture variability recovers mean advance and outlet survival but overestimates variance, so Ellis and Herschel-Bulkley results remain independent-channel predictions. The model provides an interpretable reference limit separating rheology-controlled hydraulic selection from matrix-controlled transport.
Comments9 pages, 9 figures, 3 tables. Published in Advances in Water Resources
Journal refAdvances in Water Resources 218 (2026) 105507
DOI：10.1016/j.advwatres.2026.105507
