Visualization of transitional pipe flow using the photochromic tracer method
| Autor: | Paul Zalzal, Matadial Ojha, R. S. C. Cobbold, C. R. Ethier, K. W. Johnston |
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| Rok vydání: | 1994 |
| Předmět: |
Fluid Flow and Transfer Processes
Flow visualization Physics Leading edge business.industry Turbulence Mechanical Engineering Computational Mechanics Laminar flow Mechanics Condensed Matter Physics Vortex Pipe flow Physics::Fluid Dynamics symbols.namesake Optics Mechanics of Materials symbols Trailing edge business Doppler effect |
| Zdroj: | Physics of Fluids. 6:2003-2010 |
| ISSN: | 1089-7666 1070-6631 |
| DOI: | 10.1063/1.868207 |
| Popis: | Two noninvasive measurement techniques are described for investigating transitional flow in a rigid straight tube. Photochromic trace recordings, representing fluid displacement profiles, were made within the core and at the leading and trailing edges of turbulent slugs generated by a disturbance at the tube inlet. Consistent photochromic trace recordings were made possible through the discovery that Doppler ultrasound can be used to detect the passage of turbulent slugs, thereby allowing precise timing of the photochromic traces. Upstream and downstream Doppler probes enabled the leading and trailing edge velocities of slugs to be measured and also enabled the laminar/turbulent transition regions to be investigated in detail. Trailing edge interface velocities were in excellent agreement with existing data, while leading edge velocities agreed less well. Turbulence generation at the trailing edge appeared to be associated with a localized vortical structure which originated in the near wall region and th... |
| Databáze: | OpenAIRE |
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