Thanks I think I see how it would be done. I would think that you could see how the entire airframe would behave if you used an accurate test model of the aircraft.

So you would use the dimensionless numbers (In this case Reynolds) as your constant. And adjust your flow so that you would have the same Reynolds number. Sounds easy enough to do, and at least a very interesting experiment.
Do you think that a channel 5 to 6 times the model is large enough to prevent interaction with the walls to be eliminated? (Square plastic would be easy to build it to at least around 16 inches wide and deep up to 8 feet long.)
You also had mentioned using glycerin ("Now if you really want to have some fun, get some glycerin and do the tests in that. The viscosity is huge and you can really slow the flow down and see what is going on. One cool trick is to take a syringe filled with some colored glycerin and inject it into the flow of glycerin and you can see the streamlines around the airfoil.")does using such a dense material mean that you need a larger trough to move outside of the skin effect coming into play?