Experiments on the laminar oscillatory flow of wormlike micellar solutions
- 272 Downloads
We report new experimental results of the oscillatory flow of a solution of giant micelles in a narrow vertical tube. We explore small driving amplitudes (laminar flow) and a large range of driving frequencies. High-resolution particle image velocimetry measurements of the flow field in a meridional plane of the tube show that the velocity magnitude at the tube axis peaks at well-defined resonance frequencies, where the phase lag with the forcing changes abruptly. The velocity field is highly inflectional and eventually exhibits some hints of shear banding. The results are compared with theoretical predictions based on the upper-convected Maxwell and Oldroyd-B models of the linear shear rheology of the solution, and observed coincidences and discrepancies are discussed in detail.
KeywordsOscillatory flow Micellar solutions Resonances PIV
We acknowledge M. Quevedo and A. Comerma for their help in assembling the experimental setup and designing the electronics, respectively. We are very grateful also to A. Morozov for fruitful discussions. L.C. is supported by the Ministerio de Educación (Spain) through a FPU AP2008-03903 fellowship. The work has received financial support from ME (Spain), projects nr. FIS2006-03525 and FIS2010-21924-C02-02, and from Generalitat de Catalunya, project nr. 2009-SGR-0014.
- Bird RB, Armstrong RC, Hassager O (1987) Dynamics of polymeric liquids, vol 1, 2nd edn. Wiley, New YorkGoogle Scholar
- Herb CA, Prud’homme RK (1994) Structure and flow of surfactant solutions. Eds ACS Washington (Symp Ser 578)Google Scholar
- Lambossy P (1952) Oscillations forcées d’un liquide incompressible et visqueux dans un tube rigide et horizontal. Calcul de la force de frottement. Helv Phys Acta 25:371–386Google Scholar
- Larson RG (1999) The structure and rheology of complex fluids, 9th edn. Oxford University Press, OxfordGoogle Scholar
- Müller A (1954) Über die Verwendung des Pitot-Rohres zur Geschwindigkeitsmessung. Helv Phys Acta 12:98–111Google Scholar
- Raffel M, Willert C, Werely S, Kompenhans J (2007) Particle image velocimetry, a practical guide. Springer, BerlinGoogle Scholar
- del Río JA, López de Haro M, Whitaker S (2001) Erratum: enhancement in the dynamic response of a viscoelastic fluid flowing in a tube. [Phys Rev E 58,6323 (1998)]. Phys Rev E 64:039901(E)Google Scholar
- Womersley JR (1955) Method for the calculation of velocity, rate of flow and viscous drag in arteries when the pressure gradient is known. J Physiol 127:553–563Google Scholar