Quite a number of years ago I was involved with putting a contract in place with the US Army to have them come up and test a full-size model of what was then going to be their latest and greatest version of this same sort of weapon. It was simply called BAT (for Brilliant Anti-Tank) - I believe. It became known as the BAT Test.
Anyhow we had (and still do have) the only commercially-available vertical wind tunnel (in the "friendly" world) capable of doing the work - and some would say crazy enough.
The test involved suspending the test article in the centre of the airflow initially in its pre-deployed configuration. We time synched 8 high speed (film) cameras (and two first generation high speed video cameras) to spin up a fraction of a second before the BAT then deployed (via small explosive charges).
The data collected was the video footage - to see where the dunage flew (ie. whether it would get tangled with the deployed struts and fins that were to start the BAT rotating / slowing down and going into "seeker" mode.) (In real life there was a sensor in its head and it would guide the BAT to a position right over a target, fire a high explosive charge and drive a DU "bullet" into the target.)
A bunch of people (me included, once) stood around the airstream with big fishing nets and when the airflow was shut off seconds after the deployment we would "fish" as much falling dunage out of the air before it fell to the settling chamber below (which is a pain to get into to clean out.)
Most of the dunage was pinned to a capture net above the test section (and just in front of the fan blades) when the wind was on, and dropped as the flow slowed down. But smaller articles (like nuts and bolts) could pass through and hit the fans blades.
And that folks is why those wind tunnel blades (and those in many tunnels) are made from laminated wood. Easy to remove any impaled stuff and make repairs - unlike metal blades.
I can tell you this only because way back when we had the Army's permission to say what I said above. Otherwise Mum's the word - especially about all that other neat stuff that we do for a ton of clients!
