This page gives supplementary information regarding my technique, described in a manuscript accepted for publication in Chemical Engineering Education, for illustrating natural convection in a classroom with an overhead projector.
Here are four DivX movies showing projected schlieren images of free convection above a tea candle:
DivX is a “codec,” a means of compressing and decompressing AVI video files. To view the movies you will need to install the codec on your computer. The codec itself is free for personal use (the DivX group charges money or uses adware for special media players with features you don’t necessarily need). Once you install the standard codec on a Windows PC, you can play DivX movies using any general-purpose media player. There are free DivX players for Macintosh and Linux platforms. DivX is functionally equivalent to MPEG4.
The graphics files below allow you to print the required stripe filters onto transparencies using a laser printer. They were created with Adobe Illustrator and may be modified using the same.
This material, including movies and images, is copyright 2004 by Dean Wheeler. Without specific prior approval, you may use this material only in accordance with the “fair use” provision of U.S. copyright law. If the intended use is nonprofit and educational, it is probably covered under this provision.