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Development and decay of vortex flows in viscoelastic fluids between concentric cylinders
Renzo Guido1, Felipe Rinderknecht1, Cecilia Cabeza1
1Iguá 4225, Instituto de Física, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay.
Summary
This study investigates vortex dynamics in viscoelastic fluids using experiments and simulations. We characterized vortex development and decay using overshoot and undershoot parameters, revealing fluid property dependencies.
Area of Science:
- Fluid Dynamics
- Rheology
- Polymer Science
Background:
- Vortex dynamics in viscoelastic fluids are crucial in various industrial applications.
- Understanding transient phenomena like vortex development and decay is essential for process optimization.
Purpose of the Study:
- To experimentally and numerically investigate the development and decay of vortices in viscoelastic fluids.
- To characterize transient vortex behavior using overshoot and undershoot parameters.
- To explore the influence of fluid elasticity and shear-thinning on vortex dynamics.
Main Methods:
- Experimental study using polyacrylamide and glycerin solutions between coaxial cylinders.
- Numerical simulations employing Oldroyd-B and White-Metzer rheological models.
- Digital Particle Image Velocimetry (DPIV) for azimuthal velocity measurements.
Main Results:
- Azimuthal velocity exhibits oscillations during transient vortex development and decay.
- Overshoot and undershoot parameters quantify vortex development and decay, respectively.
- Oldroyd-B model shows dependence of overshoot/undershoot on elasticity number.
- White-Metzer model explains increased overshoot due to shear-thinning effects from reduced solvent viscosity.
Conclusions:
- Viscoelastic fluid behavior during transient vortex formation and decay is complex.
- Elasticity and shear-thinning significantly influence vortex dynamics.
- The study provides insights into the rheological control of vortex phenomena.
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