Non-axisymmetric instability of core-annular flow

Howard H. Hu*, Neelesh Patankar

*Corresponding author for this work

Research output: Contribution to journalConference articlepeer-review


Stability of core-annular flow of water and oil in a vertical circular pipe is studied with respect to non-axisymmetric disturbances. Results show that when the oil core is thin, the flow is most unstable to the asymmetric sinuous mode of disturbance, and the core moves in a form of corkscrew waves as observed in experiments. The asymmetric mode of disturbance is the most dangerous mode for quite a wide range of material and flow parameters. This asymmetric mode persists in vertical pipes with upward and downward flows and in horizontal pipes. The analysis also applies to the instability of a freely rising axisymmetric cigarette smoke or thermal plume. The study predicts a unique wave length for the asymmetric meandering waves.

Original languageEnglish (US)
Pages (from-to)33-39
Number of pages7
JournalAmerican Society of Mechanical Engineers, Applied Mechanics Division, AMD
StatePublished - Dec 1 1994
EventProceedings of the 1994 International Mechanical Engineering Congress and Exposition - Chicago, IL, USA
Duration: Nov 6 1994Nov 11 1994

ASJC Scopus subject areas

  • Mechanical Engineering

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