This research focuses on the relationship between the observed length scales of overturns in stably-stratified shear-flow turbulence and the fundamental length scales constructed from dimensional analysis of basic physical quantities. In geophysical flows such as the ocean, overturns are relatively easy to observe while the basic quantities are not. As such, overturns provide a means of inferring basic quantities if the relationship between the observed and fundamental scales are known. In turn, inferred values of the basic quantities, namely the turbulent kinetic energy k, and the dissipation rate of turbulent kinetic energy epsilon, can be used to estimate diapycnal diffusivity (i.e. turbulent mixing). Most commonly, the observed Thorpe length scale, LT, is assumed to scale linearly with the fundamental Ozmidov scale, LO=(epsilon/N 3) 1/2, so that inferred values of epsilon can be obtained and used to estimate mixing from the Osborn formulation for diapycnal diffusivity. A major goal of this research is to re-examine this and other possible scalings using dimensional analysis, direct numerical simulation (DNS), laboratory data, and field observations. (Abstract shortened by UMI.).
展开▼
机译：这项研究的重点是在稳定分层的剪切流湍流中观测到的倾覆长度尺度与通过基本物理量的尺寸分析构造的基本长度尺度之间的关系。在海洋等地球物理流中，相对容易观察到倾覆，而基本量则不易观察到。这样，如果已知观测尺度和基本尺度之间的关系，则倾覆提供推断基本数量的手段。反过来，基本量的推断值，即湍动能k和湍动能ε的耗散率，可以用来估计对向扩散率（即湍流混合）。最常见的是，假设观察到的索普长度尺度LT与基本的Ozmidov尺度LO =（epsilon / N 3）1/2线性成比例，因此可以得出ε的推断值，并用于从中推论混合。 Osborn配方，用于二向扩散。这项研究的主要目标是使用尺寸分析，直接数值模拟（DNS），实验室数据和现场观察来重新检查此缩放比例和其他可能的缩放比例。 （摘要由UMI缩短。）。
展开▼
