Stratified wake Signatures Generated by Propagating Submerged Bodies in the Presence of an Active Internal Wave Field
Abstract
This study characterizes the detectability of a stratified wake in the presence of background internal waves using numerical simulations. To achieve this, we conducted numerical simulations on Department of Defense high-performance computing systems using the Massachusetts Institute of Technology general circulation model, which we adapted for wake simulations. The internal waves were generated by forcing fluid motion over the seafloor with the frequency of semi-diurnal tides, while the topography is simulated based on a data-based stochastic model. By varying the magnitude of the forcing, we were able to perform a series of simulations with distinct initial intensities of the internal wave field in the range that reflects typical conditions in the ocean. The submerged body is characterized as an ellipsoid, whose depth and velocity were varied in order to analyze the strength of the signatures in relation to the background noise. Our analysis reveals limited influence of the wavefield on the wakes persistence. We also estimate the noise for the turbulent and thermal dissipation rates by taking a time average over a tidal cycle prior to the introduction of the submerged body. Using this noise, we show that, for our parameters, the wake from a submerged body would be undetectable after 3060 minutes of passage. Finally, we observed that an interaction exists between the wake and the boundary layer that results in turbulence entrainment between both regions of the domain.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 2020
- Accession Number
- AD1114560
Entities
People
- Jack C. Dougherty
Organizations
- Naval Postgraduate School