Surface tension induced global destabilization of plane jets and wakes
(English)Manuscript (preprint) (Other academic)
The effect of surface tension on global stability of confined co-flow jets andwakes at a moderate Reynolds number is studied. The flow cases under studyare globally stable without surface tension. It is found that surface tensioncan cause the flow to be unstable if the inlet shear is strong enough. For evenstronger surface tension, the flow is re-stabilized. As long as there is no changeof the most unstable mode, increasing surface tension seems to decrease the oscillationfrequency and increase the wavelength of the mode. The critical shear(minimum shear at which an instability is found) is found to occur for antisymmetricdisturbances for the wakes and symmetric disturbances for the jets.However, at stronger shear, the opposite symmetry might be the most unstableone, in particular for wakes at high surface tension. The results show strongeffects of surface tension that should be possible to reproduce experimentallyas well as numerically.
IdentifiersURN: urn:nbn:se:kth:diva-34146OAI: oai:DiVA.org:kth-34146DiVA: diva2:419300