On the dynamics of wave‐mud interaction: A numerical study
On the dynamics of wave‐mud interaction: A numerical study
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波泥相互作用动力学：数值研究
DOI：
10.1029/2009jc005552
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发表时间：
2010
影响因子：
--
通讯作者：
T. Hsu
中科院分区：
文献类型：
--
作者：
A. Torres;A. Torres;T. Hsu
[1] 先前的许多研究将泥质海底的波浪衰减和底部边界层流体泥浆传输视为两个不同的研究主题。因此，与波-泥相互作用的物理相关的各种过程，例如湍流-沉积物相互作用、流变应力和非线性波-波相互作用，被相当人为地结合起来。这项工作的目的是提出一种新的建模方法，该方法允许使用一组控制方程和闭包来解决非线性波传播和底部边界层泥浆输送问题。通过采用流体-泥浆建模框架，基于雷诺平均纳维-斯托克斯 (RANS) 方程的经过充分验证的深度/相位解析波传播模型被扩展到模拟粘性沉积物输运。该数值模型由一组基于平衡欧拉方法的控制方程组成，精确地描述了细泥沙极限。当沉积物浓度接近零时，数值模型简化为清晰的流体 RANS 方程。因此，该模型能够连续一致地计算非线性波传播、波边界层过程和流体-泥浆输送，而无需规定泥浆层特征。数值模拟揭示了几个重要的物理过程，这些过程对于理解泥质海底的水波动力学至关重要：（i）由于流体泥浆和流变应力的存在而导致波边界层厚度的增加，这导致增强的波边界层和流体泥浆层之间的比例关系；（ii）由于流变效应而导致的直接波幅耗散以及通过非线性能量传递的低频和高频波衰减的明显证据。
[1] Many previous studies consider wave attenuation over muddy seabeds and bottom boundary layer fluid-mud transport as two distinct research topics. Hence, various processes related to the physics of wave-mud interaction, such as turbulence-sediment interactions, rheological stresses, and nonlinear wave-wave interactions are incorporated rather artificially. The aim of this work is to present a new modeling approach which allows for the resolution of nonlinear wave propagation and bottom boundary layer mud transport with a single set of governing equations and closures. By adopting a fluid-mud modeling framework, a well-validated depth/phase-resolving wave propagation model, based on the Reynolds-Averaged Navier-Stokes (RANS) equations, is extended to model cohesive sediment transport. The numerical model consists of a set of governing equations based on the equilibrium Eulerian approach accurate for the fine sediment limit. The numerical model reduces to the clear fluid RANS equations when the sediment concentration approaches zero. Hence, the model is able to calculate continuously and consistently the nonlinear wave propagation, wave boundary layer processes, and fluid-mud transport without the need to prescribe the mud layer characteristics. Numerical simulations reveal several important physical processes that are critical for understanding the water-wave dynamics over muddy seabeds: (i) an enhancement of the wave boundary layer thickness due to the presence of the fluid-mud and rheological stress, which leads to a scaling relation between the enhanced wave boundary-layer and the fluid-mud layer and (ii) a direct wave amplitude dissipation due to rheological effects and clear evidences of low- and high-frequency wave attenuation via nonlinear energy transfer.