Mixing by polymers 2

As fluid advances downstream and gets mixed, the contrast decreases but the characteristic size of the structures does not seem to change very much.

Random 3D flow with steeply decaying power spectrum of the velocity fluctuations is an ideal  experimental realization of the Batchelor regime of mixing in a broad range of scales. Random 3D flow with steeply decaying power spectrum of the velocity fluctuations is an ideal  experimental realization of the Batchelor regime of mixing in a broad range of scales. Efficient mixing in an open flow at arbitrarily low Re, at polymer concentration as low as 7ppm is obtained in macro- and micro-fluidic devices.

Reference: A. Groisman and V. Steinberg, Nature 410, 905 (2001)

in a microchannel: T. Burghelea, E. Segre, and V. Steinberg,

Phys. Rev. Lett.  92,  164501 (2004).