Had you thought about a junk trailer house as a large wind tunnel?
I have been doing cleaning and repairs/demo work to a junk trailer house here to make into my shop. Get my lathe into the back room now and I can either put the wall back on or install a door
(Darned truck with the lathe/mill in it won't start now, Lucky it's a boxed truck)
So anyway while working on stuff down there I got to thinking, would a gutted trailer house work for a wind tunnel? Remove inside walls, board up outside wall windows. This one is about 7-8' ceilings and 12' wide 65' long. If squared was wanted an 8' wide tunnel would leave nearly a 4' hallway beside it. Only need to build 1 wall, most of the materials already there when ripping out inside walls.
Just curious about it, I don't currantly have any wind tunnel plans, but if something like that would work farily easy often old trailer houses can be picked up for around $1,000 and moving costs. I could have bought another junk one a while back for $500 but did not want it then and no time to mess with getting it. Now I wish I had gotten it for parts, oh well.
Just thought I'd ask, maybe later you'll want a bigger tunnel like 8'x12'x70' and the thought might help a bit?