Vortex shedding around skyscrapers

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The other day I attended a really interesting doctoral defense (congrats Mustafa!) which used computational fluid dynamics to look at vortex shedding from fluid flow around various-shaped objects with prescribed motions. Check out this animated gif to get an idea what I’m talking about.

Vortex shedding is an interesting phenomenon in skyscraper design because, depending on the building’s aerodynamic characteristics, moderate wind can excite torsional modes or cause other serious problems. Nowadays any landmark skyscraper is evaluated in wind tunnels to attempt to detect this effect ahead of time.

It reminded me that a year or so ago I got interested in building a collection of photos showing vortex shedding around skyscrapers. I found two decent ones (shown above) of the John Hancock Center in Chicago, one of my favorite skyscrapers. These photos were really hard to find because most tourists taking photos from the base of a skyscraper don’t tend to tag their photos with “vortex shedding” on Flickr. The next time I’m in a big city on a windy+cloudy day, I’m going to see if I can recreate a photo like these.