Elastic instability in crossflow of polymer solutions through periodic arrays of cylinders

https://doi.org/10.1016/0377-0257(93)87025-KGet rights and content

Abstract

The kinematics of viscous and viscoelastic liquid flows transverse to periodic arrays of circular cylinders have been studied experimentally at Reynolds numbers ranging from 0.039 to 0.5. Streak photography was used to observe the flow of a dilute polyisobutylene solution in polybutene, through square and hexagonal arrays with a porosity of 70%. Unsteady flow patterns were observed at Deborah numbers above 0.5 for the hexagonal array and at Deborah numbers above 1.5 for the square array. In the case of the square array, the asymmetry of the particle paths was particularly striking. The flow resistance corresponding to each photograph has been recorded; progressively increasing flow resistance is seen to correspond to progressively increasing unsteadiness and asymmetry in the flow patterns.

The velocity profiles along selected streamline segments of another concentrated solution of polyisobutylene in decalin flowing through the same arrays, were recorded with a laser Doppler velocimeter. The Reynolds number was less than 0.01 in all the runs. At Deborah numbers up to one within the square array, the average stretch rate between rows of cylinders, determined experimentally and normalized with the nominal strain rate, increases by up to 50%. At Deborah numbers of 1–2 within the hexagonal array, the average stretch rate measured between stagnation points is the same as the corresponding value for the Stokes field. The flow field becomes unsteady with this fluid also, at Deborah numbers where the fRe product increases for both arrays.

References (21)

  • D.F. James et al.

    J. Non-Newtonian Fluid Mech.

    (1990)
  • S. Pilitsis et al.

    J. Non-Newtonian Fluid Mech.

    (1989)
  • S.R. Burdette et al.

    J. Non-Newtonian Fluid Mech.

    (1989)
  • D.A. Nguyen et al.

    J. Non-Newtonian Fluid Mech.

    (1990)
  • K. Te Nijenhuis

    J. Non-Newtonian Fluid Mech.

    (1990)
  • A.S. Sangani et al.

    Int. J. Multiphase Flow

    (1982)
  • A.G. Dodson et al.

    Rheol. Acta

    (1971)
  • J.A. Deiber et al.

    AIChE J.

    (1981)
  • A. Mageur et al.

    Chem. Eng. Commun.

    (1985)
  • S. Huzarewicz et al.

    J. Rheol.

    (1991)
There are more references available in the full text version of this article.

Cited by (44)

  • Flow-Induced Locomotion of a Flexible Filament in the Wake of a Cylinder in Non-Newtonian Flows

    2022, International Journal of Mechanical Sciences
    Citation Excerpt :

    To the best of our knowledge, the FIV problem has not been extensively studied in non-Newtonian fluid flows, and the development of knowledge in this field is required. Furthermore, some engineering problems like polymer processing of composites and micro-chip heat exchangers require studying the interaction between non-Newtonian fluid and structures [53–56]. In this study, the interaction of a structure with non-Newtonian fluid flow is compared with that of a Newtonian fluid using a non-Newtonian IB-LB-LS method that was attempted for the first time.

  • Complex flows of viscoelastic wormlike micelle solutions

    2020, Journal of Non-Newtonian Fluid Mechanics
  • Elastoviscoplastic flows in porous media

    2018, Journal of Non-Newtonian Fluid Mechanics
  • Viscoelastic flow simulations in random porous media

    2017, Journal of Non-Newtonian Fluid Mechanics
  • Flow resistance of viscoelastic flows in fibrous porous media

    2017, Journal of Non-Newtonian Fluid Mechanics
    Citation Excerpt :

    Experimental measurements of the flow resistance for polymeric flows in aligned arrays of cylinders or undulating flow channels also reported the remarkable increase in the flow resistance for the Weissenberg number beyond a critical value [2–9]. The elastic instability is considered to be responsible at least partly for such a steep increase of flow resistance: i.e., the observations of transition from 2D steady flow to three-dimensional time dependent structure with unsymmetrical flow patterns, secondary flows (vortices) and pressure fluctuations through experiments of purely elastic fluids and these flow structures would transfer the energy from the mean flow to the disturbance flow and dissipate it continuously [10–12]. Newly study by De and co-workers [13] modeled unsteady viscoelastic flows through a continuous array of cylinders.

  • A coupled finite volume immersed boundary method for simulating 3D viscoelastic flows in complex geometries

    2016, Journal of Non-Newtonian Fluid Mechanics
    Citation Excerpt :

    Flow past a single sphere, cylinder or an array of cylinders in a two dimensional environment has also been of interest in recent studies [1,2]. Chmielewski and Jayaraman [3] studied the flow of an elastic liquid through arrays of cylinders with a triangular or rectangular pitch. Their experiments were performed for a porosity of 0.70.

View all citing articles on Scopus
2

Now at Mobil Chemical Co., Edison, NJ, USA.

1

Corresponding author.

View full text