Flow visualization with TMV

The wakes of swimming fish are revealed through the flow visualization technique developed herein.

TMV visualization of the flow around an idling fish. Note the signature of intake into its mouth.

A flow visualization technique using dilute solutions of tobacco mosaic virus (TMV) is described. Rod-shaped TMV-particles align with shear, an effect that produces a luminous interference pattern when the TMV solution is viewed between crossed polarizers. Attractive features of this technique are that it is both transparent to the naked eye and benign to fish. We use it here to visualize the evolution and decay of the flows that they produce. We also report that dilute solutions of Kalliroscope are moderately birefringent and so may similarly be used for qualitative in situ flow visualizations.

Images presented here:  Hu, Goreau & Bush, Gallery of Fluid Motion (2005) .

See paper here: Hu, Goreau and Bush (2008)