Spectral Wave-Current Bottom Boundary Layer Flows
Spectral Wave-Current Bottom Boundary Layer Flows
复制标题
谱波电流底部边界层流
DOI：
10.1061/9780784400890.030
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发表时间：
2010
期刊：
影响因子：
1.6
通讯作者：
O. Madsen
中科院分区：
文献类型：
--
作者：
O. Madsen
基于线性化控制方程、由等效 Nikuradse 砂粒粗糙度 fcjv 指定的底部粗糙度和类似于 Grant 和 Madsen (1979 和 1986) 的时不变涡流粘度，获得了组合波流湍流底部边界层流的解，其波运动由其近底部轨道速度方向谱指定。该解决方案取决于先验未知的剪切速度 u*r，用于缩放波边界层内的涡流粘度。通过要求谱波流模型在简单周期平面波的限制下简化为 Grant-Madsen 模型来实现闭合。为了便于频谱波流模型的应用，它用于定义代表性周期波的特征（近底轨道速度幅度，U（，r，弧度频率，uir和传播方向，4>wr），在组合波流底部边界层流动的背景下，等效于由其方向谱指定的波。推导了模型应用所需的相关公式，并通过概述解决典型规范的波流相互作用的有效计算程序来说明它们的使用简介 在过去的几十年里，人们提出了几种与组合波流相关的湍流底部边界层的理论模型，鉴于这些不同的模型表示湍流的复杂程度存在很大差异，因此它们的最终结果大多为 1 R.M. Parsons Laboratory, Cambridge, MA 02139 USA。
Based on the linearized governing equations, a bottom roughness specified by the equivalent Nikuradse sand grain roughness, fcjv, and a timeinvariant eddy viscosity analogous to that of Grant and Madsen (1979 and 1986) the solution is obtained for combined wave-current turbulent bottom boundary layer flows with the wave motion specified by its near-bottom orbital velocity directional spectrum. The solution depends on an a priori unknown shear velocity, u*r, used to scale the eddy viscosity inside the wave boundary layer. Closure is achieved by requiring the spectral wavecurrent model to reduce to the Grant-Madsen model in the limit of simple periodic plane waves. To facilitate application of the spectral wave-current model it is used to define the characteristics (near-bottom orbital velocity amplitude, U(,r, radian frequency, uir, and direction of propagation, 4>wr) of a representative periodic wave which, in the context of combined wavecurrent bottom boundary layer flows, is equivalent to the wave specified by its directional spectrum. Pertinent formulas needed for application of the model are derived and their use is illustrated by outlining efficient computational procedures for the solution of wave-current interaction for typical specifications of the current. Introduction Over the past couple of decades several theoretical models for turbulent bottom boundary layers associated with combined wave-current flows have been proposed. In view of the vastly different levels of sophistication with which these different models represent turbulence, their end result, most 1 R.M. Parsons Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139 USA