Approximate streamsurfaces for flow visualization
| Autor: | Stergios Katsanoulis, Florian Kogelbauer, Roshan Kaundinya, Jesse Ault, George Haller |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2023 |
| Předmět: |
topological fluid dynamics
Mechanical Engineering Applied Mathematics Fluid Dynamics (physics.flu-dyn) FOS: Physical sciences Dynamical Systems (math.DS) Physics - Fluid Dynamics vortex dynamics Nonlinear Sciences - Chaotic Dynamics Condensed Matter Physics Mechanics of Materials turbulence theory FOS: Mathematics Chaotic Dynamics (nlin.CD) Mathematics - Dynamical Systems |
| Zdroj: | Journal of Fluid Mechanics, 954 |
| ISSN: | 0022-1120 1469-7645 |
| Popis: | Instantaneous features of three-dimensional velocity fields are most directly visualized via streamsurfaces. It is generally unclear, however, which streamsurfaces one should pick for this purpose, given that infinitely many such surfaces pass through each point of the flow domain. Exceptions to this rule are vector fields with a non-degenerate first integral whose level surfaces globally define a continuous, one-parameter family of streamsurfaces. While generic vector fields have no first integrals, their vortical regions may admit local first integrals over a discrete set of streamtubes, as Hamiltonian systems are known to do over Cantor sets of invariant tori. Here we introduce a method to construct such first integrals approximately from velocity data, and show that their level sets indeed frame vortical features of the velocity field in examples in which those features are known from Lagrangian analysis. Moreover, we test our method in numerical datasets, including a flow inside a V-junction and a turbulent channel flow. For the latter, we propound an algorithm to pin down the most salient barriers to momentum transport up to a given scale providing a way out of the occlusion conundrum that typically accompanies other vortex visualization methods. Journal of Fluid Mechanics, 954 ISSN:0022-1120 ISSN:1469-7645 |
| Databáze: | OpenAIRE |
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