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Rheology pp 179-184 | Cite as

Normal Stress Measurements on Viscoelastic Fluids Using Holographic Interferometry to Measure the Free Surface in the Weissenberg Effect

  • M. F. Hibberd
  • H. G. Hornung

Abstract

Results obtained to date for viscometric flows of simple fluids have not provided a very detailed picture of the normal stresses for these fluids. The normal stress ratio N2/N1 is generally agreed to lie in the range -0.1 to -0.4 for moderately concentrated polymer solutions, but some experiments show a larger range. Most difficulty is experienced measuring N2, due mainly to its nature (being the difference in stress between the two directions normal to the flow). The use of the shape of the free surface as a measure of the state of stress in a fluid has been explored on a limited scale over the past 30 years1. Theoretical work by Bohme2,3 has shown that, in restricted circumstances, it is possible to obtain expressions for the shape of the free surface of a second order fluid being sheared between two rotating solid surfaces of revolution. The experiments described here are an attempt to obtain the separate values of ψ1,0 and ψ2,0 from measurements of the Weissenberg effect in spherical symmetry (see eqn. 4), and compare them with the value of (ψ1,0 + 4. ψ2,0) from a cylindrical geometry.

Keywords

Viscoelastic Fluid Holographic Interferometry Fluid Surface Elastic Fluid Bearing Plate 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. 1.
    G.S. Beavers and D.D. Joseph, Experiments on free surface phenomena, J. non-Newtonian Fl. Mech., 5, 323–353 (1979).CrossRefGoogle Scholar
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    G. Böhme, “A theory for secondary flow phenomena in non-Newtonian fluids”, Europ. Space Res. Organ. Report No. TT 157 (1974).Google Scholar
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    G. Böhme, Rotation-symmetrische Sekundarstromungen in nicht-Newtonschen Fluiden, Rheol. Acta, 14 669–698 (1975).MATHCrossRefGoogle Scholar
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    R.J. Collier, C.B. Burckhardt and H.L. Lin, “Optical Holography”, Academic Press, New York (1971).Google Scholar
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    R.P. Chhabra, private communication.Google Scholar
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    M. Keentok, A.G. Georgescu, A.A. Sherwood and R.I. Tanner, J. non-Newtonian Fl. Mech., to appear.Google Scholar
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    M.F. Hibberd, Ph.D. thesis, A.N.U., Canberra, in preparation.Google Scholar

Copyright information

© Springer Science+Business Media New York 1980

Authors and Affiliations

  • M. F. Hibberd
    • 1
  • H. G. Hornung
    • 1
  1. 1.Department of PhysicsAustralian National UniversityCanberraAustralia

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