The RANS modelling of turbulence across fluid-porous interface regions within ribbed channels has been investigated by applying double (both volume and Reynolds) averaging to the Navier–Stokes equations. In this study, turbulence is represented by using the Launder and Sharma (Lett Heat Mass Transf 1:131–137, 1974) low-Reynolds-number $$k-\varepsilon $$ k - ε turbulence model, modified via proposals by either Nakayama and Kuwahara (J Fluids Eng 130:101205, 2008) or Pedras and de Lemos (Int Commun Heat Mass Transf 27:211–220, 2000), for extra source terms in turbulent transport equations to account for the porous structure. One important region of the flow, for modelling purposes, is the interface region between the porous medium and clear fluid regions. Here, corrections have been proposed to the above porous drag/source terms in the k and $$\varepsilon $$ ε transport equations that are designed to account for the effective increase in porosity across a thin near-interface region of the porous medium, and which bring about significant improvements in predictive accuracy. These terms are based on proposals put forward by Kuwata and Suga (Int J Heat Fluid Flow 43:35–51, 2013), for second-moment closures. Two types of porous channel flows have been considered. The first case is a fully developed turbulent porous channel flow, where the results are compared with DNS predictions obtained by Breugem et al. (J Fluid Mech 562:35–72, 2006) and experimental data produced by Suga et al. (Int J Heat Fluid Flow 31:974–984, 2010). The second case is a turbulent solid/porous rib channel flow to examine the behaviour of flow through and around the solid/porous rib, which is validated against experimental work carried out by Suga et al. (Flow Turbul Combust 91:19–40, 2013). Cases are simulated covering a range of porous properties, such as permeability and porosity. Through the comparisons with the available data, it is demonstrated that the extended model proposed here shows generally satisfactory accuracy, except for some predictive weaknesses in regions of either impingement or adverse pressure gradients, associated with the underlying eddy-viscosity turbulence model formulation.

中文翻译：

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多孔流体界面区域周围湍流的改进涡粘性建模

通过对 Navier-Stokes 方程应用双（体积和雷诺）平均来研究肋状通道内流体-多孔界面区域的湍流 RANS 建模。在这项研究中，湍流是通过使用 Launder 和 Sharma（Lett Heat Mass Transf 1:131–137, 1974）低雷诺数 $$k-\varepsilon $$k - ε 湍流模型来表示的，通过提案修改Nakayama 和 Kuwahara (J Fluids Eng 130:101205, 2008) 或 Pedras 和 de Lemos (Int Commun Heat Mass Transf 27:211–220, 2000)，在湍流传输方程中使用额外的源项来解释多孔结构。出于建模目的，流动的一个重要区域是多孔介质和透明流体区域之间的界面区域。这里，已经提出了对 k 和 $$\varepsilon $$ ε 输运方程中的上述多孔阻力/源项的修正，这些方程旨在解释多孔介质的薄近界面区域的孔隙率的有效增加，并且显着提高预测准确性。这些术语基于 Kuwata 和 Suga (Int J Heat Fluid Flow 43:35–51, 2013) 提出的关于第二时刻闭合的建议。已经考虑了两种类型的多孔通道流动。第一种情况是完全发展的湍流多孔通道流，将结果与 Breugem 等人获得的 DNS 预测进行比较。(J Fluid Mech 562:35–72, 2006) 和 Suga 等人提供的实验数据。(Int J Heat Fluid Flow 31:974–984, 2010)。第二种情况是湍流固体/多孔肋条通道流动，以检查通过固体/多孔肋条及其周围的流动行为，这与 Suga 等人进行的实验工作进行了验证。（流动湍流燃烧 91：19-40，2013 年）。案例模拟涵盖了一系列多孔特性，例如渗透率和孔隙率。通过与可用数据的比较，证明这里提出的扩展模型显示出总体上令人满意的准确性，除了与潜在涡粘性湍流模型公式相关的冲击或不利压力梯度区域中的一些预测弱点。案例模拟涵盖了一系列多孔特性，例如渗透率和孔隙率。通过与可用数据的比较，证明这里提出的扩展模型显示出总体上令人满意的准确性，除了与潜在涡粘性湍流模型公式相关的冲击或不利压力梯度区域中的一些预测弱点。案例模拟涵盖了一系列多孔特性，例如渗透率和孔隙率。通过与可用数据的比较，证明这里提出的扩展模型显示出总体上令人满意的准确性，除了与潜在涡粘性湍流模型公式相关的冲击或不利压力梯度区域中的一些预测弱点。