We experimentally investigate the generation of internal solitary waves (ISWs or waves) by intrusions (IGCs), and their interaction. We estimate the induced mixing in terms of increase of the initial pycnocline thickness. The release of a uniform fluid of intermediate density into a two-layer stratified ambient fluid leads to the formation of an IGC, which propagates downstream. The intrusion squeezes the stratified fluid it interacts with, generating a train of ISWs of decreasing size and celerity. The intrusion, dissipating, slows down, allowing the waves to gradually separate from it. The uniform sloping boundary placed downstream induce ISWs partial breaking and upstream reflection. We vary the boundary slope and its position, to induce different waves breaking mechanisms for different intrusion dissipation state. Interacting with the reflected ISWs, the IGC deepens following the pycnocline displacement, while the waves increase their celerity, since they propagate trough a narrower vertical cross section.
la Forgia, G., Ottolenghi, L., Adduce, C. (2020). Breaking of internal solitary waves generated by intrusions. In River Flow 2020 - Proceedings of the 10th Conference on Fluvial Hydraulics (pp.945-948). CRC Press/Balkema.
Breaking of internal solitary waves generated by intrusions
la Forgia G.
;Ottolenghi L.;Adduce C.
2020-01-01
Abstract
We experimentally investigate the generation of internal solitary waves (ISWs or waves) by intrusions (IGCs), and their interaction. We estimate the induced mixing in terms of increase of the initial pycnocline thickness. The release of a uniform fluid of intermediate density into a two-layer stratified ambient fluid leads to the formation of an IGC, which propagates downstream. The intrusion squeezes the stratified fluid it interacts with, generating a train of ISWs of decreasing size and celerity. The intrusion, dissipating, slows down, allowing the waves to gradually separate from it. The uniform sloping boundary placed downstream induce ISWs partial breaking and upstream reflection. We vary the boundary slope and its position, to induce different waves breaking mechanisms for different intrusion dissipation state. Interacting with the reflected ISWs, the IGC deepens following the pycnocline displacement, while the waves increase their celerity, since they propagate trough a narrower vertical cross section.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.