Models of bed-load transport across scales: turbulence signature from grain motion to sediment flux
Models of bed-load transport across scales: turbulence signature from grain motion to sediment flux
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DOI：
10.1007/s00477-022-02333-9
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发表时间：
2022-11
影响因子：
4.2
通讯作者：
C. Escauriaza;Christian González;M. Williams;W. Brevis
中科院分区：
文献类型：
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作者：
C. Escauriaza;Christian González;M. Williams;W. Brevis
泥沙输运控制着河道的演化，在地球表面大范围时空尺度的物理、生态和生物地球化学过程中起着重要作用。然而，从第一性原理发展预测输运模型和理解泥沙通量的尺度相互作用仍然是河流系统研究的巨大挑战。在这里，我们使用直接数值模拟（DNS）模拟最小尺度的输运，以探索床载动力学，并发现湍流和颗粒尺度过程如何影响输运率，表明它们的相互作用产生了一个由跨尺度传播的波动主导的临界状态。这些联系使用随机微分方程表示，并通过路径积分公式和费曼图进行统计描述，从而提供了一个包含非线性和湍流效应的框架，以模拟跨尺度的床载动力学。
Sediment transport controls the evolution of river channels, playing a fundamental role in physical, ecological, and biogeochemical processes across a wide range of spatial and temporal scales on the Earth surface. However, developing predictive transport models from first principles and understanding scale interactions on sediment fluxes remain as formidable research challenges in fluvial systems. Here we simulate the smallest scales of transport using direct numerical simulations (DNS) to explore the dynamics of bed-load and discover how turbulence and grain-scale processes influence transport rates, showing that their interplay gives rise to a critical regime dominated by fluctuations that propagate across scales. These connections are represented using a stochastic differential equation, and a statistical description through a path integral formulation and Feynman diagrams, thus providing a framework that incorporates nonlinear and turbulence effects to model the dynamics of bed-load across scales.