Hello, I'm working on a project in which I need to design and build a home-made wind tunnel, and then publish instructions on building and using such a wind tunnel. My design is intended for middle school and high school student research, so it is simple yet as aerodynamically sound as I can make it. When finished, it will be an open-circuit, closed-test section tunnel of about 6-7 feet in length. I'm using common hardware store materials to build it. I've run into a couple snags--first of all, I need a good fan for the drive system. In Pope's Low Speed Wind Tunnel Testing, it is specified that about 34 fps is ideal. I cannot find any such fan at my local Lowes or Home Depot. Anybody got any ideas about the type of fan, and/or where to get it? Also, I'm having trouble with data collection. Balances are too expensive or too difficult to build for students, so I'm looking into force probes, button load cells, and strain gauges. Anybody got any advice for me? Thanks in advance! I appreciate your help!