Stereoscopic visualization of the flows for pitched blade turbines

Tatterson, Gary B.; Yuan, Hsien-Hwa Steven; Brodkey, Robert S.

doi:10.1016/0009-2509(80)85130-x

Cited by 45 publications

(14 citation statements)

References 6 publications

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“…The results in these 45" inclined planes indicate that the flow both immediately in front and behind the blade has magnitudes of around 0.5 yip. This is in agreement with the observation of Tatterson et al (1980) that velocities in front and back of the blade are approximately the same, but their value of 0.25 I<ip was based on visualization observations and is probably an underestimation. In addition, there is no evidence of a second small and weak circulation at the upper tip of the blade, as inferred by Kresta and Wood (1993a) from their tuft flow visualization.…”

Section: Angle-resolved Mean Velocity Measurements and Trailing Vortesupporting

confidence: 91%

“…However, they indicated that the wake region behind the blade was not significant and the flow resembles a boundary layer. Tatterson et al (1980) studied the trailing vortices produced by two turbines with 45" blades, a 6-blade PBT in a 295-mm-diameter vessel, and a four blade PBT in a 914-mm vessel. Differences in the flow structures produced by the two impellers were found, but it could not be established which were due to the vessel scale and which due to the number of blades.…”

Section: Introduction and Brief Literature Surveymentioning

confidence: 99%

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Trailing vortices around a 45° pitched‐blade impeller

et al. 1998

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Section: Angle-resolved Mean Velocity Measurements and Trailing Vortesupporting

confidence: 91%

Section: Introduction and Brief Literature Surveymentioning

confidence: 99%

Trailing vortices around a 45° pitched‐blade impeller

et al. 1998

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“…The flows around the impeller region have been qualitatively and quantitatively visualized and studied through stereoscopic visualization technology by a number of researchers for many decades, (van't Riet and Smith 1975;Tatterson et al 1980;Mollet et al 2004). These studies indicated the presence of recirculation flows, jet flows, vortices in the impeller region, and strong trailing vortex originating from the impeller tips.…”

Section: Cell Damage From Agitation In Stirred Tanksmentioning

confidence: 99%

The potential of hydrodynamic damage to animal cells of industrial relevance: current understanding

Hu¹,

2011

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Suspension animal cell culture is now routinely scaled up to bioreactors on the order of 10,000 L, and greater, to meet commercial demand. However, the concern of the 'shear sensitivity' of animal cells still remains, not only within the bioreactor, but also in the downstream processing. As the productivities continue to increase, titer of ~10 g/L are now reported with cell densities greater than 2 × 10(7) cells/mL. Such high, and potentially higher cell densities will inevitably translate to increased demand in mass transfer and mixing. In addition, achieving productivity gains in both the upstream stage and downstream processes can subject the cells to aggressive environments such as those involving hydrodynamic stresses. The perception of 'shear sensitivity' has historically put an arbitrary upper limit on agitation and aeration in bioreactor operation; however, as cell densities and productivities continue to increase, mass transfer requirements can exceed those imposed by these arbitrary low limits. Therefore, a better understanding of how animal cells, used to produce therapeutic products, respond to hydrodynamic forces in both qualitative and quantitative ways will allow an experimentally based, higher, "upper limit" to be created to guide the design and operation of future commercial, large scale bioreactors. With respect to downstream hydrodynamic conditions, situations have already been achieved in which practical limits with respect to hydrodynamic forces have been experienced. This review mainly focuses on publications from both the academy and industry regarding the effect of hydrodynamic forces on industrially relevant animal cells, and not on the actual scale-up of bioreactors. A summary of implications and remaining challenges will also be presented.

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“…Tatterson et al (1980) found that pitched blade impellers also generated the trailing vortices. Hockey and Nouri (1996) employed a 60 • pitched blade impeller with six blades, and both the mean and rms velocities around the impeller using the angle-resolved LDV technique were measured.…”

Section: Introductionmentioning

confidence: 97%