An investigation of internal gravity waves generated by a buoyantly rising fluid in a stratified medium

Publisher Website
Google Scholar
Abstract
Experiments have been carried out to examine the spectrum of internal gravity waves excited in a stratified incompressible fluid during stabilization following the buoyant rise of a miscible fluid. The rise time of the buoyant fluid to its stabilization height in the stratified fluid was observed to be about 0.85 of the Brunt-Väisälä period for the stratified fluid. The motion of specific fluid elements in the wave field was observed using neutrally buoyant marker particles, and the particle trajectories were found to be in close accord with theoretical predictions. Observations on the internal waves generated by the forced oscillation of a spherical body suspended in the stratified medium showed the wave pattern to be well behaved and similar to that described by Mowbray & Rarity. However, the gravity wave field generated by the motion of the buoyant fluid was observed to be inhomogeneous and transient in nature. Wave periods from one to four times the Brunt-Väisälä period were clearly observed and at later times it appeared that the motion tended towards vertical oscillations a t the Brunt- Väisälä frequency.