Die Engineering Wonders; Part 1

It was just this morning while perusing the world wide web that it dawned on me… Where have all the intellectual posts gone?

So in a bid to return the community of Die Emmers once again to the road of the righteous and well informed (with mostly useless facts) I will be sharing the wonders of the modern engineering world when they manifest themselves in unusual ways.

Yes, yes I can hear the moans but just think when your kids (or when you start having kids) ask, What’s that Daddy?!

You can comfortably answer:


That my son is a…. Karman vortex street, one of the best known vortex patterns in fluid mechanics. The vortex street is just a special type of unsteady separation over bluff bodies (or an island as in the image). The vortex street is highly periodic having a frequency which is proportional to U/D, where D is the length of the bluff body measured transverse to the flow and U is the incoming flow speed. This periodicity is responsible for the "singing" of telephone wires. In fact, vortex streets are almost always involved when the wind generates a fairly pure tone as it blows over obstacles.

Ahh now don't we all feel a little more enlightened?