Letter | Published:

Onset of Instabilities and Reduction of Drag in the Flow of Relaxing Liquids through Tubes and Porous Beds

Naturevolume 212pages388390 (1966) | Download Citation



Jones and Williams1,2 showed that the onset of instabilities in the flow of gaseous carbon dioxide through tubes and through porous materials occurred at a value of the Reynolds number Re which was different from the value of Re when instabilities occurred in the flow of gaseous nitrogen, through the same tube or porous material. The difference was attributed to the relaxation of a vibrational mode of the carbon dioxide molecule, the vibrational mode either absorbing or emitting energy to the bulk motion of the gas depending on the conditions of the experiment. As a consequence of the experiments and their interpretation, it was anticipated that very similar effects would occur in the flow of relaxing (that is, visco-elastic) liquids through tubes and porous materials; preliminary experiments confirming these predictions are reported here. (There are also theoretical reasons for expecting the onset of instabilities to be different in a relaxing liquid, compare Thomas and Walters3; considerable drag reduction has also been observed in the turbulent flow of such liquids through tubes4.)

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. 1

    Jones, W. M., and Williams, I. B., Nature, 183, 531 (1959).

  2. 2

    Jones, W. M., and Williams, I. B., Brit. J. App. Phys., 14, 877 (1963).

  3. 3

    Thomas, R. H., and Walters, K. J., Fluid Mech., 18, 33 (1964).

  4. 4

    Savins, J. G., J. Inst. Petrol., 50, 203 (1964).

  5. 5

    Jones, W. M., Brit. J. App. Phys., 7, 370 (1956).

Download references

Author information


  1. Department of Physics, University College of Wales, Penglais, Aberystwyth

    • W. M. JONES
    •  & J. L. MADDOCK


  1. Search for W. M. JONES in:

  2. Search for J. L. MADDOCK in:

About this article

Publication history

Issue Date



Further reading


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.