Photo link:  How much propane does it take to melt a pool? – Flow Visualization

Attribution: Samuel Hatton

This is my favorite flow visualization image that I found on the web, from our course website (get wet assignment last year).  This piece was created by Samuel Hatton, who used a propane jet on a pool of water.  When the flame hit the water, it rapidly cooled, causing the flame to change colors.  The viewer can see the initial semi-laminar flow coming from the propane tank, then hitting the water, spreading out, and becoming a turbulent flow.  This is the most artistically interesting demonstration of rapid cooling after combustion.

The composition of this photo is also very impressive.  The focus clearly shows the ripples of the flame hitting the water, and the black background (presumably taken at night) helps draw all of the focus to the flame.  The shutter speed helped freeze a very short moment of the flow, allowing a clear view of an instant of the flow.