Abstract
A three-dimensional flow transition behind a heated cylinder is analyzed at low Reynolds numbers: Re=O(100). Both visualizations and numerical simulations show that the transition manifests itself in the form of mushroom-type structures in the far wake and Lambda-shaped structures in the near wake. The legs of the Lambda-shaped structures coincide with streamwise vorticity regions. An intermediate stage is observed between the Lambda-shaped structures and the escaping mushroom-type structures. This intermediate step is characterized by a lift-up process, which takes place in the center region between the legs and head of the Lambda-shaped structures. As a result, hot fluid is being pulled out of the upper vortex core. Due to this lift-up process, mushroom-type structures are generated in the form of escaping vortex rings in the far wake.
| Original language | English |
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| Pages (from-to) | 014106-1/12 |
| Journal | Physics of Fluids |
| Volume | 18 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 2006 |