| Autor: |
Xin Huang, Estruch-Samper, David |
| Předmět: |
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| Zdroj: |
Journal of Fluid Mechanics; 12/10/2018, Vol. 856, p797-821, 25p |
| Abstrakt: |
High-speed turbulent boundary-layer separation can lead to severe wall-pressure fluctuations, often extending over a swept shock region. Having noted the shear layer's influence within axisymmetric step flows, tests go on to experimentally assess the unsteadiness of a canonical swept separation, caused by a slanted 90°-step discontinuity (with varying azimuthal height) over an axisymmetric turbulent boundary layer. Results document an increase in shock pulsation frequency along the swept separation region (Δ ⩽ 30° sweep angles) - whereby the recirculation enables downstream feedback via the reverse flow - as the local streamwise separation length is reduced. A link between the spanwise variation in the separation shock's low-frequency instability and the downstream mass ejection rate, as large shear-layer eddies leave the bubble, is sustained. The local entrainment-recharge dynamics of swept separation are thereby duly evaluated. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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