The smallest of the range is the 250 Wind Tunnel, which is designed to be installed on a laboratory bench. Less than 8’ (1.9m) long, it still offers a working section of more than 18" (450mm) long and 5" (125mm) square, allowing a variety of realistic demonstrations to be performed.
Air is drawn through the entrance cone into the test section by a variable speed fan. A plastic honeycomb flow straightener with an L:D ratio of 10:1, assures a laminar air flow through the test section. The entrance cone has a contraction ratio of 12:1, down to a test section measuring 5" x 5" x 18" long. The air velocity through the test section is variable up to 82 fps (25m/s).
The test section has clear acrylic side walls and top to give a clear observation of the test in progress. The other flow sections are fabricated from 14 gauge steel formed sections.
A series of accessories are available for laboratory demonstrations to provide hands-on, visual learning. A further accessory allows the system to be connected to a user supplied computer, and includes an interface card and Labview software.
A set of airfoils are available as optional accessories, allowing the flow over both upper and lower surfaces to be measured and compared with theory. Also available is a very popular golf ball demonstration, which allows the students to investigate the effect of dimples on the ball. This very practical and highly visual demonstration is an excellent introduction to the effect of aerodynamics in a real world situation.