Dan Kelley
Dalhousie University, Halifax, Canada
Below are shown a few examples that illustrate the type of fluid flow problems that can be handled with AESTUS.
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Kelvin-Helmholtz instability: To see if AESTUS could handle the development of dynamical instabilities we set the model to reproduce the laboratory experiment of Thorpe (1968) on Kelvin-Helmholtz instabilities. The figure on the left shows the development of instabilities as simulated by AESTUS. A side-by-side comparison with Thorpe's observations shows that the model reproduces remarkably well the first stages of the development of instabilities. Discrepancies between model results and laboratory observations become apparent when the flow developd strong three-dimensionality. |
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Internal wave breaking: This is another test we made to see how AESTUS deals with internal wave propagation and breaking on a slope. For this case we reproduced the laboratory conditions of Michallet and Ivey (1999). The model results are in good agreement with the laboratory observations up to the point where three-dimensionality effects become important, which, for this case, happens after the initial wave breaking. |
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2D convection and turbulence: This is an example to show that AESTUS can deal with highly unstable conditions and can simulate ocean convection. At this point this is more a pretty color figure than a real test since we have not yet compared the numerical results for convection againsts theory or observations. |
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Sill processes: This is the result of an ocean scale application of AESTUS that takes advantage of the "laterally-averaged" capability of the model. The model was set to simulate the stratified tidal flow in Knight Inlet and the numerical results are compared with field observations from Farmer and Armi (1999). The comparison is quite encouraging since the model can reproduce some of the important nonhydrostatic phenomena such as the generation of large-amplitude lee waves as seen on this figure. |