Vortex structure behind highly heated two cylinders in parallel arrangements
| Autor: | Yuji Yahagi, Eiichirou Kurita |
|---|---|
| Rok vydání: | 2009 |
| Předmět: |
Fluid Flow and Transfer Processes
Physics Mechanical Engineering Reynolds number Mechanics Wake Condensed Matter Physics Kármán vortex street Cylinder (engine) law.invention Vortex Physics::Fluid Dynamics symbols.namesake Classical mechanics Flow velocity Heat flux law Condensed Matter::Superconductivity symbols Strouhal number |
| Zdroj: | Heat Transfer-Asian Research. 38:194-206 |
| ISSN: | 1523-1496 1099-2871 |
| DOI: | 10.1002/htj.20244 |
| Popis: | Vortex structures behind twin, highly heated cylinders in parallel arrangements have been investigated experimentally. The experiments were conducted under the following conditions: cylinder diameter, D=4mm; mean flow velocity, U∞ = 1.0 m/s; Reynolds number, Re=250; cylinder clearance, S/D=0.5 to 1.4; and cylinder heat flux, q=0 to 72.6kW/m2. For S/D>1.2, the Karman vortex street is formed alternately behind each cylinder divided on the slit flow. The slit flow velocity increases with a decrease in S/D and decreases with increasing heat flux. For S/D < 1.2, the wake vortexes become asymmetric having small and large scale vortexes divided by the slit flow. In the small scale vortexes, the symmetric counter-rotating twin vortexes are formed just behind the cylinders. In the large scale vortexes, the generated vortexes have a similar structure to a Karman vortex even though the Strouhal number is approximately half of the ordinary single cylinder vortex. For isothermal conditions, the transition phenomena from symmetric to asymmetric wake structures are observed in the range of 0.9 < S/D |
| Databáze: | OpenAIRE |
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