Turbulence in dilute polymers

This is my main research project at IHW IfU.

Goals

  • The main goal is a comparative study of the small scale properties of a quasi-isotropic turbulence in a Newtonian fluid (water) and in dilute polymer solution (up to 100 wppm)
  • The research is done primarily by using three-dimensional particle tracking velocimetry (3D-PTV) system, allowing to measure the velocity field, the field of velocity derivatives in time and in a Lagrangian manner.
  • The expectation is to identify the influence of polymers on the fields of strain, vorticity, dissipation, enstrophy and their production in turbulent flows.

    • Experimental setup

    The quasi-isotropic and homogeneous flow is produced by 8 counter-rotating disks on two opposite walls of the following apparatus. The scheme on the right shows the direction of rotation of 4 disks on one wall, in so-called “four-mill” configuration.

    The apparatus and the scheme of the quasi-isotropic turbulent flow forcing.

    The flow is seeded with 30 micron polystyrene particles and it is illuminated by 20 Watt CW Ar-Ion laser.

    Observation volume

    The observation volume is of 10 x 10 x 10 mm and it the tracer motion is recorded with 4 CCD cameras:

    Four CCD cameras

    The result of the 3D-PTV is the field of tracer positions, velocities and velocity derivatives fields in Lagrangian manner. The example is shown below, as the banch of particle trajectories in the observation volume.

    Particle trajectories in the observation volume

    References (see also Publications page)

    Liberzon A., Guala M., Lüthi B., Kinzelbach W. and Tsinober A. (2005) Dilute polymers in turbulence, accepted for publication, Phys. Fluids

    Liberzon A., Guala M., Lüthi B., Kinzelbach W. and Tsinober A. (2005) Lagrangian and Eulerean aspects of turbulent flow of dilute polymer solutions, in advanced stage of preparation.Our poster, presented on the G floor of HIL building, ETH Honggerberg.
    Slide1.JPG
    Very nice picture of the poly(ethylene oxide) chain - Link