Extracting energetically dominant flow features in a complicated fish wake using singular-value decomposition
| Autor: | Shang-Chieh Ting, Jing-Tang Yang |
|---|---|
| Rok vydání: | 2009 |
| Předmět: |
Fluid Flow and Transfer Processes
Physics Mechanical Engineering Computational Mechanics Wake Vorticity Condensed Matter Physics Vortex Physics::Fluid Dynamics symbols.namesake Classical mechanics Flow (mathematics) Flow velocity Particle image velocimetry Mechanics of Materials Singular value decomposition Froude number symbols Biological system |
| Zdroj: | Physics of Fluids. 21:041901 |
| ISSN: | 1089-7666 1070-6631 |
| DOI: | 10.1063/1.3122802 |
| Popis: | We developed a method to extract the energetically dominant flow features in a complicated fish wake according to an energetic point of view, and applied singular-value decomposition (SVD) to two-dimensional instantaneous fluid velocity, vorticity and λ2 (vortex-detector) data. We demonstrate the effectiveness and merits of the use of SVD through an example regarding the wake of a fish executing a fast-start turn. The energy imparted into the water by a swimming fish is captured and portrayed through SVD. The analysis and interpretation of complicated data for the fish wake are greatly improved, and thus help to characterize more accurately a complicated fish wake. The velocity vectors and Galilean invariants (i.e., vorticity and λ2) resulting from SVD extraction are significantly helpful in recognizing the energetically dominant large-scale flow features. To obtain successful SVD extractions, we propose useful criteria based on the Froude propulsion efficiency, which is biologically and physically relate... |
| Databáze: | OpenAIRE |
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