Modification of the flow structures in a swirling jet

Research output: Chapter in Book/Report/Conference proceedingConference PaperResearchpeer-review

Abstract

The effect of a downstream bluff body on upstream vortex breakdown has been investigated in an open-flow, motivated by the potential for tissue culture in swirling flow bioreactors. A sphere was placed on the central axis of a swirling jet issuing into a tank of stagnant water. The position of the stagnation point of a vortex breakdownwas tracked as a result of varying the azimuthal Reynolds number.While it is known that an increase in azimuthal Reynolds number leads to the upstream movement of the vortex breakdown stagnation point, this investigation focuses on the position of the vortex breakdown as a function of sphere size, axial Reynolds numbers, and sphere position. It was found that the distance from the jet exit to the stagnation point scaled with axial Reynolds number to the half-power, and that distinctive flow topologies of closed and open recirculation zones were found that were analogous to the cone and bubble forms previously found. Varying the size of the sphere was found to affect the flow only for sphere diameters comparable or larger than that of the nozzle - a smaller sphere size was found not to modify the flow significantly from the no-sphere case. Finally, the distance of the sphere from the nozzle affected the stagnation point location in the near-nozzle region. A correlation was also found between the swirl setting for various sphere distances at which the vortex breakdown changed form, with the swirl setting that gave the same stagnation point position with the no-sphere case.

Original languageEnglish
Title of host publicationIUTAM Symposium on Unsteady Separated Flows and their Control - Proceedings of the IUTAM Symposium "Unsteady Separated Flows and their Control"
Pages243-253
Number of pages11
Volume14
DOIs
Publication statusPublished - 2009
EventIUTAM Symposium on Unsteady Separated Flows and their Control 2007 - Corfu Greece, Corfu, Greece
Duration: 18 Jun 200722 Jun 2007

Publication series

NameSolid Mechanics and its Applications
Volume14
ISSN (Print)18753507

Conference

ConferenceIUTAM Symposium on Unsteady Separated Flows and their Control 2007
CountryGreece
CityCorfu
Period18/06/0722/06/07

Keywords

  • Bioreactors
  • Bluff-bodies
  • Incompressible flow
  • Stagnation point
  • Vortex breakdown

Cite this

Atvars, K., Thompson, M., & Hourigan, K. (2009). Modification of the flow structures in a swirling jet. In IUTAM Symposium on Unsteady Separated Flows and their Control - Proceedings of the IUTAM Symposium "Unsteady Separated Flows and their Control" (Vol. 14, pp. 243-253). (Solid Mechanics and its Applications; Vol. 14). https://doi.org/10.1007/978-1-4020-9898-7_21
Atvars, K. ; Thompson, M. ; Hourigan, K. / Modification of the flow structures in a swirling jet. IUTAM Symposium on Unsteady Separated Flows and their Control - Proceedings of the IUTAM Symposium "Unsteady Separated Flows and their Control". Vol. 14 2009. pp. 243-253 (Solid Mechanics and its Applications).
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abstract = "The effect of a downstream bluff body on upstream vortex breakdown has been investigated in an open-flow, motivated by the potential for tissue culture in swirling flow bioreactors. A sphere was placed on the central axis of a swirling jet issuing into a tank of stagnant water. The position of the stagnation point of a vortex breakdownwas tracked as a result of varying the azimuthal Reynolds number.While it is known that an increase in azimuthal Reynolds number leads to the upstream movement of the vortex breakdown stagnation point, this investigation focuses on the position of the vortex breakdown as a function of sphere size, axial Reynolds numbers, and sphere position. It was found that the distance from the jet exit to the stagnation point scaled with axial Reynolds number to the half-power, and that distinctive flow topologies of closed and open recirculation zones were found that were analogous to the cone and bubble forms previously found. Varying the size of the sphere was found to affect the flow only for sphere diameters comparable or larger than that of the nozzle - a smaller sphere size was found not to modify the flow significantly from the no-sphere case. Finally, the distance of the sphere from the nozzle affected the stagnation point location in the near-nozzle region. A correlation was also found between the swirl setting for various sphere distances at which the vortex breakdown changed form, with the swirl setting that gave the same stagnation point position with the no-sphere case.",
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Atvars, K, Thompson, M & Hourigan, K 2009, Modification of the flow structures in a swirling jet. in IUTAM Symposium on Unsteady Separated Flows and their Control - Proceedings of the IUTAM Symposium "Unsteady Separated Flows and their Control". vol. 14, Solid Mechanics and its Applications, vol. 14, pp. 243-253, IUTAM Symposium on Unsteady Separated Flows and their Control 2007, Corfu, Greece, 18/06/07. https://doi.org/10.1007/978-1-4020-9898-7_21

Modification of the flow structures in a swirling jet. / Atvars, K.; Thompson, M.; Hourigan, K.

IUTAM Symposium on Unsteady Separated Flows and their Control - Proceedings of the IUTAM Symposium "Unsteady Separated Flows and their Control". Vol. 14 2009. p. 243-253 (Solid Mechanics and its Applications; Vol. 14).

Research output: Chapter in Book/Report/Conference proceedingConference PaperResearchpeer-review

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AB - The effect of a downstream bluff body on upstream vortex breakdown has been investigated in an open-flow, motivated by the potential for tissue culture in swirling flow bioreactors. A sphere was placed on the central axis of a swirling jet issuing into a tank of stagnant water. The position of the stagnation point of a vortex breakdownwas tracked as a result of varying the azimuthal Reynolds number.While it is known that an increase in azimuthal Reynolds number leads to the upstream movement of the vortex breakdown stagnation point, this investigation focuses on the position of the vortex breakdown as a function of sphere size, axial Reynolds numbers, and sphere position. It was found that the distance from the jet exit to the stagnation point scaled with axial Reynolds number to the half-power, and that distinctive flow topologies of closed and open recirculation zones were found that were analogous to the cone and bubble forms previously found. Varying the size of the sphere was found to affect the flow only for sphere diameters comparable or larger than that of the nozzle - a smaller sphere size was found not to modify the flow significantly from the no-sphere case. Finally, the distance of the sphere from the nozzle affected the stagnation point location in the near-nozzle region. A correlation was also found between the swirl setting for various sphere distances at which the vortex breakdown changed form, with the swirl setting that gave the same stagnation point position with the no-sphere case.

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BT - IUTAM Symposium on Unsteady Separated Flows and their Control - Proceedings of the IUTAM Symposium "Unsteady Separated Flows and their Control"

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Atvars K, Thompson M, Hourigan K. Modification of the flow structures in a swirling jet. In IUTAM Symposium on Unsteady Separated Flows and their Control - Proceedings of the IUTAM Symposium "Unsteady Separated Flows and their Control". Vol. 14. 2009. p. 243-253. (Solid Mechanics and its Applications). https://doi.org/10.1007/978-1-4020-9898-7_21