Pulsatility role in cylinder flow dynamics at low Reynolds number

Handle URI:
http://hdl.handle.net/10754/562018
Title:
Pulsatility role in cylinder flow dynamics at low Reynolds number
Authors:
Qamar, Adnan; Samtaney, Ravi ( 0000-0002-4702-6473 ) ; Bull, Joseph L.
Abstract:
We present dynamics of pulsatile flow past a stationary cylinder characterized by three non-dimensional parameters: the Reynolds number (Re), non-dimensional amplitude (A) of the pulsatile flow velocity, and Keulegan-Carpenter number (KC = Uo/Dωc). This work is motivated by the development of total artificial lungs (TAL) device, which is envisioned to provide ambulatory support to patients. Results are presented for 0.2 ≤ A ≤ 0.6 and 0.57 ≤ KC ≤ 2 at Re = 5 and 10, which correspond to the operating range of TAL. Two distinct fluid regimes are identified. In both regimes, the size of the separated zone is much greater than the uniform flow case, the onset of separation is function of KC, and the separation vortex collapses rapidly during the last fraction of the pulsatile cycle. The vortex size is independent of KC, but with an exponential dependency on A. In regime I, the separation point remains attached to the cylinder surface. In regime II, the separation point migrates upstream of the cylinder. Two distinct vortex collapse mechanisms are observed. For A < 0.4 and all KC and Re values, collapse occurs on the cylinder surface, whereas for A > 0.4 the separation vortex detaches from the cylinder surface and collapses at a certain distance downstream of the cylinder. The average drag coefficient is found to be independent of A and KC, and depends only on Re. However, for A > 0.4, for a fraction of the pulsatile cycle, the instantaneous drag coefficient is negative indicating a thrust production. © 2012 American Institute of Physics.
KAUST Department:
Mechanical Engineering Program; Physical Sciences and Engineering (PSE) Division; Clean Combustion Research Center; Fluid and Plasma Simulation Group (FPS)
Publisher:
American Institute of Physics
Journal:
Physics of Fluids
Issue Date:
2012
DOI:
10.1063/1.4740504
Type:
Article
ISSN:
10706631
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division; Mechanical Engineering Program; Clean Combustion Research Center

Full metadata record

DC FieldValue Language
dc.contributor.authorQamar, Adnanen
dc.contributor.authorSamtaney, Ravien
dc.contributor.authorBull, Joseph L.en
dc.date.accessioned2015-08-03T09:42:56Zen
dc.date.available2015-08-03T09:42:56Zen
dc.date.issued2012en
dc.identifier.issn10706631en
dc.identifier.doi10.1063/1.4740504en
dc.identifier.urihttp://hdl.handle.net/10754/562018en
dc.description.abstractWe present dynamics of pulsatile flow past a stationary cylinder characterized by three non-dimensional parameters: the Reynolds number (Re), non-dimensional amplitude (A) of the pulsatile flow velocity, and Keulegan-Carpenter number (KC = Uo/Dωc). This work is motivated by the development of total artificial lungs (TAL) device, which is envisioned to provide ambulatory support to patients. Results are presented for 0.2 ≤ A ≤ 0.6 and 0.57 ≤ KC ≤ 2 at Re = 5 and 10, which correspond to the operating range of TAL. Two distinct fluid regimes are identified. In both regimes, the size of the separated zone is much greater than the uniform flow case, the onset of separation is function of KC, and the separation vortex collapses rapidly during the last fraction of the pulsatile cycle. The vortex size is independent of KC, but with an exponential dependency on A. In regime I, the separation point remains attached to the cylinder surface. In regime II, the separation point migrates upstream of the cylinder. Two distinct vortex collapse mechanisms are observed. For A < 0.4 and all KC and Re values, collapse occurs on the cylinder surface, whereas for A > 0.4 the separation vortex detaches from the cylinder surface and collapses at a certain distance downstream of the cylinder. The average drag coefficient is found to be independent of A and KC, and depends only on Re. However, for A > 0.4, for a fraction of the pulsatile cycle, the instantaneous drag coefficient is negative indicating a thrust production. © 2012 American Institute of Physics.en
dc.publisherAmerican Institute of Physicsen
dc.titlePulsatility role in cylinder flow dynamics at low Reynolds numberen
dc.typeArticleen
dc.contributor.departmentMechanical Engineering Programen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.contributor.departmentClean Combustion Research Centeren
dc.contributor.departmentFluid and Plasma Simulation Group (FPS)en
dc.identifier.journalPhysics of Fluidsen
dc.contributor.institutionUniversity of Michigan, Ann Arbor, MI 48109-2110, United Statesen
kaust.authorQamar, Adnanen
kaust.authorSamtaney, Ravien
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