Near-wake structure of a single gas bubble in a two-dimensional liquid-solid fluidized bed: Vortex shedding and wake size variation
1988; Elsevier BV; Volume: 43; Issue: 5 Linguagem: Inglês
10.1016/0009-2509(88)85077-2
ISSN1873-4405
AutoresKatsumi Tsuchiya, Liang‐Shih Fan,
Tópico(s)Particle Dynamics in Fluid Flows
ResumoThe fluid mechanic behavior of a single gas bubble and its wake in a two-dimensional liquid-solid fluidized bed was examined visually via a video camera moving at the same s peed as the bubble. The bubble wake was observed to consist of two regions: primary wake (near wake) and secondary wake. Wake formation-shedding mechanisms were illustrated for both symmetric and asymmetric shedding modes. The shedding frequency, expressed in terms of the Strouhal number, was shown to be a function of the bubble Reynolds number but independent of particle properties. The boundaries between the primary and secondary wakes were qualitatively identified for several wake structures. The primary-wake size periodically varies in the form of a saw-tooth wave function, while the liquid wake exhibits no appreciable cyclic variation in size.
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