More Schlieren: 10.12.10

Schlieren photography is a visual process that is used to photograph the flow of fluids of varying density

There are several methods commonly used to visualize refractive index or density changes in liquids, gases, liquids and solids.

Generically these include shadowgraphs, schlieren and interferometric techniques. These sytems are used to visualize temperature gradients, shock waves in wind tunnels, nonhomogeneous areas in sheet glass, convection patterns in liquids, etc.

The focusing schlieren method:


http://people.rit.edu/andpph/text-schlieren-focus.html