Jan 31 2013 I know almost nothing about fluid dynamics but my
article about wingtip vortices two weeks ago piqued my interest
in the subject. Last weekend I learned about this amazing
phenomenon, the von Kármán vortex street, animated above by
Cesareo de La Rosa Siqueira. Von Kármán vortex streets occur
when a fluid flows past a stationary object and generates a long
line of vortices that swirl in opposite directions. The
phenomenon was named for Theodore von Kármán, the man who
described it, and is probably called a street because it looks
like one. We usually don’t see von Kármán vortex streets in the
wind, but it’s important that engineers plan for them. If a tall
structure is uniformly straight the vortices can make it fall
down. Click here to read about a famous mistake. On a small
scale, von Kármán vortex streets make telephone wires sing in
the wind. On a large scale they’re visible from outer space when
clouds blow past a tall island. Here’s a picture taken from the
space shuttle that shows cloud cove