The effect of crossflow on vortex rings

Rajes Sau, Krishnan Mahesh

Research output: Chapter in Book/Report/Conference proceedingConference contribution

5 Scopus citations


DNS is performed to study passive scalar mixing in vortex rings in the presence, and absence of crossflow. For vortex rings without crossflow, the 'formation number' (Gharib et. al 1998) is found to be 3.6. Simulations are performed for a range of stroke ratios encompassing the formation number. In the absence of crossflow, the optimal stroke ratio for mixing and entrainment is shown to be at the formation number; the trailing column is not seen to be as beneficial as the ring itself. However, in the presence of crossflow, the trailing column is shown to contribute significantly to the overall mixing and entrainment. The trailing column enhances the entrainment significantly because of the high pressure gradient created by deformation of the column upon interacting with crossflow. It is shown that the crossflow reduces the stroke ratio beyond which the trailing column forms. This reduction in stroke ratio is due to entrainment of crossflow fluid during formation of the ring, and depends on the velocity ratio.

Original languageEnglish (US)
Title of host publicationCollection of Technical Papers - 45th AIAA Aerospace Sciences Meeting
PublisherAmerican Institute of Aeronautics and Astronautics Inc.
Number of pages14
ISBN (Print)1563478900, 9781563478901
StatePublished - 2007
Event45th AIAA Aerospace Sciences Meeting 2007 - Reno, NV, United States
Duration: Jan 8 2007Jan 11 2007

Publication series

NameCollection of Technical Papers - 45th AIAA Aerospace Sciences Meeting


Other45th AIAA Aerospace Sciences Meeting 2007
Country/TerritoryUnited States
CityReno, NV


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