Benthic Tubulence and Mixing Induced by Nonlinear Internal Waves
Abstract
The transition to a primary instability in the footprint of nonlinear internal waves of depression was investigated using spectral multidomain-based numerical simulations. The fully nonlinear internal wave fields were supplied through a highly nonlinear extended Korteweg De Vries algorithm generated by Sakai & Redekopp (2007). Results were qualitatively similar to the findings of Diamessis and Redekopp (2006). In the absence of an oncoming current, no transition was observed. Introducing a current and with a sufficiently strong wave amplitude and Reynolds number, the separated bottom boundary layer under the wave and behind its trough experienced a shear instability, accompanied by vortex shedding, powerful bottom shear-stresses and strong near-bed vertical velocities, indicating potential for resuspension. The vortex shedding was intermittent, consisting of bursts of 5-6 eject vortices alternating with calm periods. A subcritical nonlinear transition to turbulence was also identified and is currently under investigation.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 31, 2010
- Accession Number
- ADA520127
Entities
People
- Peter J Diamessis
Organizations
- Cornell University College of Engineering