This image reveals the intricate wake structure left behind two cylinders rotating in a fluid.
Image Credit: Sanjay Kumar and Benito Gonzalez, Department of Engineering, The University of Texas at Brownsville
For the image above, physicists rotated two cylinders at the same rate in a fluid, revealing a symmetrical wake pattern. The slightest differences between the two cylinders' rotational speed, however, quickly eliminate the symmetrical patterns.
The scientists behind this research hope it will lead to new insights for fluid control in mixers. To visualize and track this flow, the physicists generated tiny hydrogen bubbles and placed them in the stream. Because the bubbles are so small, their buoyancy effects can be ignored.