Departmental Papers (MEAM)

Document Type

Journal Article

Date of this Version



Suggested Citation:
Hu, Howard H. and Daniel D. Joseph (1989) Stability of a core-annular flow in a rotating pipe. Physics of Fluids. Vol. 1(10).

Copyright 1989 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.

The following article appeared in Physics of Fluids and may be found at

NOTE: At the time of publication, author Howard H. Hu was affiliated with the University of Minnesota. Currently, he is a faculty member in the Department of Mechanical Engineering and Applied Mechanics at the University of Pennsylvania.


The linear stability of core-annular flow in rotating pipes is analyzed. Attention is focused on the effects of rotating the pipe and the difference in density of the two fluids. Both axisymmetric and nonaxisymmetric disturbances are considered. Major effects of the viscosity ratio, interfacial tension, radius ratio, and Reynolds number are included. It is found that for two fluids of equal density the rotation of the pipe stabilizes the axisymmetric (n= 0) modes of disturbances and destabilizes the nonaxisymmetric modes. Except for small script R sign, where the axisymmetric capillary instability is dominant, the first azimuthal mode of disturbance |n| = 1 is the most unstable. When the heavier fluid is outside centripetal acceleration of the fluid in the rotating pipe is stabilizing; there exists a critical rotating speed above which the flow is stabilized against capillary instability for certain range of small script R sign. When the lighter fluid is outside the flow is always unstable.



Date Posted: 18 August 2010

This document has been peer reviewed.