Abstract In this study, multiphase Eulerian–Lagrangian large-eddy simulation (LES) is used to analyze the interaction between local flow structures, convective heat transfer and particle depositions (fouling) for a turbulent channel flow with a dimpled surface. Thus, eddy-resolving LES is applied for calculation of the turbulent working fluid (carrier flow), combined with an efficient Lagrangian particle tracking (LPT) algorithm, suitable to predict the trajectories of the suspended foulant particles precisely in time and space. In order to decrease the computational effort and to enhance the applicability of the proposed approach, deposited particles are deactivated and converted into a second continuous phase (fouling layer), which is modeled as a porous medium and accounts for the hydraulic losses as well as for the additional thermal resistance due to the fouling deposits. Prior to the fouling simulations, the envisaged method is validated for a turbulent particle-laden channel flow at Re τ = 150 , based on DNS results available in the literature, which shows the capability of the Eulerian–Lagriangian LES of capturing the flow physics within turbulent particle-laden, wall-bounded flows. Based on this observations, fouling simulations were carried out for a turbulent particle-laden channel flow over a staggered arrangement of sharp-edged spherical dimples, whereby two different dimple depth-to-diameter ratios are considered ( d / D = 0.26 and 0.35). The thermo-hydraulic performance is analyzed for the clean and contaminated dimpled surfaces.

中文翻译：

---

结构化传热表面颗粒污垢的多相欧拉-拉格朗日 LES

摘要 在这项研究中，多相欧拉-拉格朗日大涡模拟 (LES) 用于分析具有凹坑表面的湍流通道流的局部流动结构、对流热传递和颗粒沉积（污垢）之间的相互作用。因此，涡解析LES被应用于湍流工作流体（载流）的计算，结合高效的拉格朗日粒子跟踪（LPT）算法，适用于在时间和空间上精确预测悬浮污垢粒子的轨迹。为了减少计算工作量并提高所提出方法的适用性，沉积的颗粒被钝化并转化为第二个连续相（污垢层），它被建模为多孔介质，并考虑了水力损失以及由于污垢沉积而产生的额外热阻。在结垢模拟之前，基于文献中可用的 DNS 结果，对 Re τ = 150 处的充满颗粒的湍流通道流验证了设想的方法，该结果显示了欧拉-拉格朗日 LES 捕获内部流动物理的能力充满颗粒的湍流，有壁边界的流动。基于这一观察结果，对交错排列的尖锐边缘球形凹坑上的充满颗粒的湍流通道流进行了污垢模拟，其中考虑了两种不同的凹坑深度直径比（d / D = 0.26 和 0.35） . 分析了清洁和污染的凹坑表面的热液压性能。