Splitting, merging and spanwise wavenumber selection of Dean vortex pairs

Ligrani, Phillip M.; Longest, J. E.; Kendall, Michael R.; Fields, William A.

doi:10.1007/bf00209360

Cited by 40 publications

(11 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This work attempts to explain this behavior and offers a possible explanation of this uncharacteristic particle behavior at higher flow rates. Overall, this work demonstrates the presence of multiple Dean vortices in low-aspect-ratio, rectangular spiral microchannels, which is consistent with observations at specific Dean numbers in many curved macroscale channels 45 47 . These secondary vortices also offer justification for the entrapment of particles, and uncharacteristic focusing of particles, which are observed at higher De and Re .…”

Section: Resultssupporting

confidence: 88%

“…In curved macrochannels, a wide variety of methods have been used to study the fluid behavior including dye and smoke contrast and perturbation methods3335454650. For example, Dean used perturbation methods to study the behavior of Newtonian fluids in curved pipes35 and Ligrani et al 45.…”

Section: Resultsmentioning

confidence: 99%

“…For example, Dean used perturbation methods to study the behavior of Newtonian fluids in curved pipes35 and Ligrani et al 45. and Sugiyama et al 47.…”

Section: Resultsmentioning

confidence: 99%

“…Hence, the strength of secondary flows is strongly dependent on the dimensions of the channel cross-section and radius of curvature. Note that some other investigations determine the Dean number based on a channel width-length scale, instead of hydraulic diameter 45 46 47 .…”

Section: Resultsmentioning

confidence: 99%

“…These results are comparable with the secondary flow behavior at macro-scale where multiple Dean vortices are observed for high De. In fact, it has been reported that in macrochannels these additional vortices develop beyond a critical Dean number ( De C ) depending on the aspect ratio of the channel 35 45 46 47 48 49 . Although the simulations computationally confirm the presence of multiple vortices in microchannels, we observed that the shift in focusing position of RBCs occurred at much lower De ~37 than indicated by the simulations.…”

Section: Resultsmentioning

confidence: 99%

See 4 more Smart Citations

Dean Flow Dynamics in Low-Aspect Ratio Spiral Microchannels

Nivedita

Ligrani

Papautsky

2017

Sci Rep

233

170

View full text Add to dashboard Cite

A wide range of microfluidic cell-sorting devices has emerged in recent years, based on both passive and active methods of separation. Curvilinear channel geometries are often used in these systems due to presence of secondary flows, which can provide high throughput and sorting efficiency. Most of these devices are designed on the assumption of two counter rotating Dean vortices present in the curved rectangular channels and existing in the state of steady rotation and amplitude. In this work, we investigate these secondary flows in low aspect ratio spiral rectangular microchannels and define their development with respect to the channel aspect ratio and Dean number. This work is the first to experimentally and numerically investigate Dean flows in microchannels for Re > 100, and show presence of secondary Dean vortices beyond a critical Dean number. We further demonstrate the impact of these multiple vortices on particle and cell focusing. Ultimately, this work offers new insights into secondary flow instabilities for low-aspect ratio, spiral microchannels, with improved flow models for design of more precise and efficient microfluidic devices for applications such as cell sorting and micromixing.

show abstract

Section: Resultssupporting

confidence: 88%

Section: Resultsmentioning

confidence: 99%

“…For example, Dean used perturbation methods to study the behavior of Newtonian fluids in curved pipes35 and Ligrani et al 45. and Sugiyama et al 47.…”

Section: Resultsmentioning

confidence: 99%