Nonlinear steady states to Langmuir circulation in shallow layers: an asymptotic study
| Autor: | D. T. Hayes, William R. Phillips |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
010504 meteorology & atmospheric sciences
Meteorology Linear system Computational Mechanics Perturbation (astronomy) Astronomy and Astrophysics Rayleigh number Mechanics 01 natural sciences Instability 010305 fluids & plasmas Nonlinear system Waves and shallow water Geophysics Geochemistry and Petrology Mechanics of Materials 0103 physical sciences 14. Life underwater Boundary value problem Physics::Atmospheric and Oceanic Physics Geology 0105 earth and related environmental sciences Langmuir circulation |
| Zdroj: | Geophysical & Astrophysical Fluid Dynamics. 111:65-90 |
| ISSN: | 1029-0419 0309-1929 |
| DOI: | 10.1080/03091929.2016.1263302 |
| Popis: | The nonlinear steady states of perturbation equations describing the instability of wavy shear flows to counter-rotating vortical structures aligned with the flow in shallow water layers is considered. The structures are described by the Craik–Leibovich equations and are known as Langmuir circulation; they arise through an instability that requires the presence of shear U′ and differential drift D′ of the same sign provided a threshold Rayleigh number is exceeded. Of specific interest here is the aspect ratio of the Langmuir circulation and how that ratio is affected by nonlinearities when the layer is shallow, as in coastal waters and estuaries. For context it is known from observation that the aspect ratio (width of two cells to depth) is two to three in deep water, whereas in shallow waters it can range up to ten. Accordingly, while the ratio for deep water is well predicted by linear theory, the ratio for shallow water is not, which explains why nonlinearities are of interest. Present always, ... |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|