Turbulence transportation across permeable interfaces is investigated using direct numerical simulation, and the connection between the turbulent surface flow and the pore flow is explored. The porous media domain is constructed with an in-line arranged circular cylinder array. The effects of Reynolds number and porosity are also investigated by comparing cases with two Reynolds numbers ( $$Re\approx 3000,6000$$ R e ≈ 3000 , 6000 ) and two porosities ( $$\varphi =0.5,0.8$$ φ = 0.5 , 0.8 ). It was found that the change of porosity leads to the variation of flow motions near the interface region, which further affect turbulence transportation below the interface. The turbulent kinetic energy (TKE) budget shows that turbulent diffusion and pressure transportation work as energy sink and source alternatively, which suggests a possible route for turbulence transferring into porous region. Further analysis on the spectral TKE budget reveals the role of modes of different wavelengths. A major finding is that mean convection not only affects the distribution of TKE in spatial space, but also in scale space. The permeability of the wall also have an major impact on the occurrence ratio between blow and suction events as well as their corresponding flow structures, which can be related to the change of the Kármán constant of the mean velocity profile.

中文翻译：

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湍流通道流中穿过渗透界面的湍流传输：界面分辨直接数值模拟

使用直接数值模拟研究了穿过渗透界面的湍流传输，并探索了湍流表面流和孔隙流之间的联系。多孔介质域由串联排列的圆柱阵列构成。雷诺数和孔隙率的影响还通过比较两个雷诺数 ($$Re\approx 3000,6000$$R e ≈ 3000 , 6000 ) 和两个孔隙率 ( $$\varphi =0.5,0.8$$ φ = 0.5 , 0.8 )。发现孔隙度的变化导致界面区域附近流动运动的变化，进一步影响界面下方的湍流输运。湍流动能 (TKE) 收支表明，湍流扩散和压力输送交替作为能量汇和源，这表明湍流转移到多孔区域的可能途径。对光谱 TKE 预算的进一步分析揭示了不同波长模式的作用。一个主要发现是平均对流不仅影响空间空间中的 TKE 分布，而且影响尺度空间中的分布。壁面的渗透率对吹吸事件的发生率及其相应的流动结构也有重要影响，这可能与平均速度剖面的卡门常数的变化有关。