Stress Testing Airfoil Models

[waealu]

I am currently preparing for a few wind tunnel tests on a NACA 2412 airfoil. The lab technician told me that before I can use the tunnel, I need to provide solid proof that the models will be able to hold up in the wind tunnel (up to speeds of 110 mph (30 psf)).

In the technician's own words, "we need to know, without doubt, the models will not break in our tunnel. Model failure could destroy the facility. Typically we expect to see detailed engineering analysis or realistic proof loading (with a factor of safety) prior to testing."

Does anyone know how I might be able to go about stress testing my models? They are airfoils made of solid plastic (chord length of 6" and span of 24"). So far, the only thing I can come up with is to stick them out of my airplane (when I am going >110 mph) and see if they can withstand the force. However, this doesn't seem like a very professional or accurate way to go about testing these airfoils.

Thank you.

 

[Cyrus]

You should evaluate the stresses numerically using something like solid works with the material properties defined from the manufacturer.

 

[FredGarvin]

It's a dubious statement that a model breaking will ruin a facility. That being said, damage can be done that is expensive to fix. Before any wind tunnel testing I have done, structural analysis of the test article was always presented and reviewed.

Like Cyrus said, numerical and theoretical analysis is the way to go.