Lagrangian coherent superstructures in stratified turbulence
Rolf HoldereggerCollaborateurs du projet
2019 - 2023Coopération
Stratified turbulence occurs in nature when water is discharged into lakes or the ocean; it appears above the atmospheric boundary layer, where buoyancy forms plumes of cumulus clouds; and it is central in the design of heat exchangers, where cold fluid entering the top of the exchanger rapidly falls and mixes with warm fluid underneath. Large-scale coherent flow structures, termed superstructures (SSs), play a key role in these flows by controlling the overall rate of mass and momentum transport. However, progress in our understanding of the mechanics of SSs has been hampered by arbitrariness in the detection methods of these coherent flow structures and hence leading to contrasting classifications of the results or even misinterpretations of physical mechanisms. The aim of this project is to develop 3D Lagrangian coherent structure identification methods and apply them to experimental particle tracking and numerical simulation data of shear flows with stratification.