Wind Tunnel Design Parameters

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Sorry I'm no help...but it sounds an interesting project...what are you planning to use it for?

Classroom demontrations and testing of different airfoil designs. Google reveals a lot of leads, however I am hoping someone with practical experience will volunteer information.

You could use the back of a truck/ute. Mount what you are testing safely, and I mean it. I once tested a roof contraption/system and it nearly ended in disaster. I suppose your class room will have to watch the video. Have even more fun. Ky.

Hi, I have just been through this process, as I lecture in automotive aerodynamics at a college in the UK but they do not have a wind tunnel.

I worked very hard to design and make a tunnel based on a 5500 cubic foot 24 inch diameter ventilation fan. Sorry to mix units but the test section was 700 mm long by 250 mm high by 400mm wide so that a reasonable wing could be installed and still have a reasonable - less than 20 % - blockage ratio.

My theoretical speed was 88 miles per hour, but in reality the wind speed indicator from a light aircraft, shows only around 40 mph due to excess losses and fan stalling. In fact the fan acts in a radial rather than the expected axial flow and really seems to be struggling to get up to revs.

For your interest the intake funnel is 850 mm square withrounder entry radii, and the fan is 600 mm dia. The whole system is made from heavyweight - 2400 gram/metre square - glass composite fabric in polyester resin.

Hope this helps