The hydrodynamic stability of flow in a rotating pipe Is investigated experimentally using thermistors. The experimental apparatus consists of a rotating pipe made of lucite, 3-1/4 inch inside diameter, six feet long, equipped with porous plugs at the ends to minimize recirculation. The working fluid is water and a range of axial and tangential Reynolds numbers up to 7,000 and 20,000, respectively, is covered. Thermistors were chosen for this study since their high electrical resistivity yields strong signals which permit the use of inexpensive and convenient electronics. They also have a high temperature coefficient of electrical resistance which minimizes the problem of noise due to brushes and slip rings. The intensity of the signal and the signal to noise ratio are better by an order of magnitude than those attainable with platinum film probes. The probes are rugged, inexpensive and are commercially available. The major problem encountered is their low frequency response. This, however, does not limit their usefulness in determining transition from laminar to turbulent flow regimes, as can be seen from the results of the present investigation, which were verified by visual diagnostic techniques utilizing dye streaks and hydrogen bubbles.

Meeting Name

Symposium on Turbulence Measurements in Liquids (1969: Sep., Rolla, MO)


Chemical and Biochemical Engineering

Document Type

Article - Conference proceedings

Presentation Type

Contributed Paper


Selected Turbulence Measurements Papers

Document Version

Final Version

File Type





© 1972 University of Missouri--Rolla, All rights reserved.