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Showing 1 to 6 of 6 for “"stratified shear flows"”.
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Dynamics of Periodic Stratified Shear Flows
In questa tesi studiamo le instabilità in fluidi stratificati laminari dove la stratificazione in densità ha un effetto stabilizzante. Nonostante l idea comune che la forza d Archimede abbia un effetto stabilizzante, in alcune circostanze tale stratificazione ha mostrato di poter indurre …
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Instability and Energy Growth in Stratified Shear Flows
The dynamics of stratified shear flows are extremely complex due to the interplay between shear and buoyancy effects. In addition, the breakdown from a laminar state into a turbulent one is a process that is far from completely understood, despite aspects of turbulence being studied for over a …
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Waves and turbulence in sustained stratified shear flows
The speed and efficiency of stratified turbulent mixing in homogenising temperatures, chemical composition and flow speeds makes it one of farthest reaching fluid mechanical phenomenon for life on earth. It is an aesthetically beautiful phenomenon, rich in complex physical behaviours and extremely …
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Linear and nonlinear dynamics in stratified shear flows
Stably stratified shear flows, in which a less dense layer of fluid lies above and moves counter to a more dense layer below, are ubiquitous in geophysical fluid dynamics. These are often found to be unstable if the non-dimensional Richardson number Ri, quantifying the strength of stratification to …
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Prediction of turbulent mixing at the interface of density stratified, shear flows using CFD
Numerical simulations were performed involving stratified, shear flows that have been investigated experimentally. One set of simulations dealt with a homogeneous shear flow involving miscible fluids. The other set of simulations dealt with a developing shear layer involving immiscible fluids. The …
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Generalised nonlinear stability of stratified shear flows: adjoint-based optimisation, Koopman modes, and reduced models
… problems in the nonlinear stability of density stratified plane Couette flow. I begin by describing the history of transient growth phenomena, and in particular the recent application of adjoint based optimisation to find nonlinear optimal perturbations and associated minimal seeds for …