LABORATORY EXPERIMENTS ON TURBULENT TRANSITION IN THE BOTTOM BOUNDARY LAYER UNDER IRREGULAR WAVES

Wave Boundary Layer Processes Over an Irregular Bottom

A series of field observations are being carried out to address the objectives outlined above. Measurements of the wave and current field over a broad region of a coral reef are used to determine energy dissipation in an integral sense. Near-bed observations at smaller scales using acoustic profilers deployed on the Rough Boundary Profiler (RBP) then characterize the spatial structure of the bo...

Internal gravity waves generated by a turbulent bottom Ekman layer

Internal gravity waves excited by the turbulent motions in a bottom Ekman layer are examined using large-eddy simulation. The outer flow is steady and uniformly stratified while the density gradient is set to zero at the flat lower wall. After initializing with a linear density profile, a mixed layer forms near the wall separated from the ambient stratification by a pycnocline. Two types of int...

Turbulent Boundary-Layer Separation

This article summarizes our present understanding of the physical behavior of two-dimensional turbulent separated flows, which occur due to adverse pressure gradients around streamlined and bluff bodies. The physical behavior of turbulence is flow dependent, so detailed experimental infor­ mation is needed for understanding such flows and modeling their physics for calculation methods. An earli...

Negative turbulent production during flow reversal in a stratified oscillating boundary layer on a sloping bottom

Turbulent boundary layer equations

We study a boundary layer problem for the Navier-Stokes-alpha model obtaining a generalization of the Prandtl equations conjectured to represent the averaged flow in a turbulent boundary layer. We solve the equations for the semi-infinite plate, both theoretically and numerically. The latter solutions agree with some experimental data in the turbulent boundary layer.