A systematic variation of the exposure level of a spherical particle in an array of multiple spheres in a high Reynolds number turbulent open-channel flow regime was investigated while using the Large Eddy Simulation method. Our numerical study analysed hydrodynamic conditions of a sediment particle based on three different channel configurations, from full exposure to zero exposure level. Premultiplied spectrum analysis revealed that the effect of very-large-scale motion of coherent structures on the lift force on a fully exposed particle resulted in a bi modal distribution with a weak low wave number and a local maximum of a high wave number. Lower exposure levels were found to exhibit a uni-modal distribution.

中文翻译：

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相干结构超大规模运动与泥沙颗粒的相互作用

在使用大涡模拟方法的同时，研究了在高雷诺数湍流明渠流动状态下，多个球形阵列中球形颗粒的暴露水平的系统变化。我们的数值研究基于从完全暴露到零暴露水平的三种不同通道配置分析了沉积物颗粒的流体动力学条件。预乘谱分析表明，相干结构的超大规模运动对完全暴露的粒子上的升力的影响导致了双模态分布，其低波数弱且高波数局部最大值。发现较低的暴露水平表现出单峰分布。