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Instability of streamwise vortices in plane channel flows
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Jimenez, J. Coughlin, K. Moser, R. D. |
| Copyright Year | 1994 |
| Description | We present analysis and numerical experiments on the instability of streamwise vortices in 'minimal channel' flows and argue that this instability is a key feature in the observed intermittent cycle of formation, break-up, and re-formation of these structures. The base flow is a three-component, two-dimensional pair of counter-rotating rolls with axes aligned along the direction of the mean shear. While it is not a steady solution to the Navier-Stokes equations, we show numerically that this flow is unstable on a fast time scale to a secondary, three-dimensional Floquet mode. The growth of the secondary instability does not saturate in a new equilibrium, but continues until highly unstable local shear layers form and the entire flow breaks down into turbulence. Our analysis is motivated in part by the strong similarities between the intermittent turbulent cycle in minimal channel flows and one studied, both experimentally and in computations, in Couette-Taylor flow. |
| File Size | 1392180 |
| Page Count | 16 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19950014632 |
| Archival Resource Key | ark:/13960/t8cg4n83n |
| Language | English |
| Publisher Date | 1994-12-01 |
| Access Restriction | Open |
| Subject Keyword | Fluid Mechanics And Heat Transfer Shear Layers Base Flow Turbulence Three Dimensional Flow Vortices Floquet Theorem Couette Flow Channel Flow Counter Rotation Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
