Using particle tracking to measure flow instabilities in an undergraduate laboratory experiment
- 1 March 2011
- journal article
- Published by American Association of Physics Teachers (AAPT) in American Journal of Physics
- Vol. 79 (3), 267-273
- https://doi.org/10.1119/1.3536647
Abstract
Much of the drama and complexity of fluid flow occurs because its governing equations lack unique solutions. The observed behavior depends on the stability of the multitude of solutions, which can change with the experimental parameters. Instabilities cause sudden global shifts in behavior. We have developed a low-cost experiment to study a classical fluid instability. By using an electromagnetic technique, students drive Kolmogorov flow in a thin fluid layer and measure it quantitatively with a webcam. They extract positions and velocities from movies of the flow using Lagrangian particle tracking and compare their measurements to several theoretical predictions, including the effect of the drive current, the spatial structure of the flow, and the parameters at which instability occurs. The experiment can be tailored to undergraduates at any level or to graduate students by appropriate emphasis on the physical phenomena and the sophisticated mathematics that govern them.Keywords
This publication has 25 references indexed in Scilit:
- Lagrangian Properties of Particles in TurbulenceAnnual Review of Fluid Mechanics, 2009
- Electromagnetically controlled multi-scale flowsJournal of Fluid Mechanics, 2006
- Prediction of a global climate change on JupiterNature, 2004
- Uniform resonant chaotic mixing in fluid flowsNature, 2003
- Fluid instabilities and wakes in a soap-film tunnelAmerican Journal of Physics, 1999
- Bifurcations and pattern formation in a two-dimensional Navier-Stokes fluidPhysical Review E, 1995
- Experiments with Turbulent Soap FilmsPhysical Review Letters, 1995
- Instabilities in two-dimensional spatially periodic flows. Part I: Kolmogorov flowPhysics of Fluids A: Fluid Dynamics, 1992
- Two-dimensional grid turbulence in a thin liquid filmJournal de Physique Lettres, 1984
- Kolmogorov flow and laboratory simulation of itRussian Mathematical Surveys, 1983