[论文解读] Scale Collapse of Vortices at Porous-Fluid Interfaces

Justin Courter, Vishal Srikanth+2 more|arXiv (Cornell University)|Jan 15, 2026

Heat and Mass Transfer in Porous Media被引用 0

一句话总结

该论文表明在高孔隙率的多孔-流体界面处，宏观尺度涡旋会突然崩塌；而多孔介质内的湍流由孔隙尺度几何决定，与外部强迫无关。

ABSTRACT

The interaction between externally generated turbulence and porous media is central to many engineering and environmental flows, yet the fate of macroscale vortical structures at a porous/fluid interface remains uncharacterized. By numerically simulating the turbulent flow, we investigate the penetration, breakdown, and turbulence kinetic energy (TKE) transport of macroscale vortices impinging on porous matrices with high porosities $ϕ$ = 0.80-0.95. For all porosities considered, macroscale vortices collapse abruptly at the porous interface and do not persist within the matrix, supporting the pore-scale prevalence of turbulence even under strong external forcing. Although vortex impingement injects TKE into the porous medium through turbulent transport at the interface, this supplied TKE is rapidly redistributed and dissipated as the flow reorganizes to satisfy pore-scale geometric constraints. Deeper within the porous layer, turbulence is sustained primarily by local shear production associated with pore-scale velocity gradients, and the internal flow becomes increasingly independent of upstream conditions. Variations in porosity modulate the relative balance between production and dissipation by altering geometric confinement and effective Reynolds number, but the dominant turbulent length scale within the porous matrix remains set by the pore size. These results demonstrate that porous media act as a robust geometric filter that enforces pore-scale-dominated turbulence regardless of the external forcing.

研究动机与目标

• 研究在高孔隙度（φ = 0.80–0.95）时，冲击多孔介质的宏观尺度涡旋结构的命运。
• 描述穿透、破坏及穿孔介质内的湍流动能传输。
• 确定孔隙度如何影响多孔层内的产生、耗散和湍流分布。

提出的方法

• 数值模拟在高孔隙度（φ = 0.80–0.95）的多孔基质中的湍流流动相互作用。
• 追踪宏观尺度涡旋在多孔基质中的崩溃与缺失。
• 分析界面处的湍流传输与多孔介质内的TKE重新分布/耗散。
• 评估孔隙尺度速度梯度如何驱动内部剪切产生并维持湍流。
• 考察孔隙度通过受限与有效雷诺数调制产生与耗散之间的平衡的方式。

实验结果

研究问题

• RQ1 当外部由湍流强迫时，高孔隙度的多孔基质中宏观尺度涡旋是否仍然存在？
• RQ2 在多孔-流体界面及多孔介质内，湍流动能如何传输和重新分配？
• RQ3 孔隙尺度几何和孔隙度在决定多孔层内主导湍流机制方面起何作用？

主要发现

• 在多孔界面处宏观尺度涡旋突然崩塌，并且在所研究的所有孔隙度中都不会在基质内持续存在。
• 涡旋撞击通过界面湍流传输将TKE注入多孔介质，但随着流动重新配置以适应孔隙尺度约束，这些TKE迅速重新分布并耗散。
• 在多孔层内，湍流主要由孔隙尺度速度梯度的局部剪切产生来维持，并且越来越不受上游条件的影响。
• 多孔基质内的主导湍流尺度仍由孔径决定。
• 孔隙度的变化通过改变几何约束和有效雷诺数来调制产生与耗散之间的平衡，但内部湍流仍以孔隙尺度为主导。