Tuesday, August 13, 2013

Apogee Newsletter article on wind tunnels

The current issue of the Apogee Peak of Flight Newsletter, Issue 345 is entitled "Exploring Rocketry Using Research Wind Tunnels."  This is not a tutorial on using wind tunnels but rather explains how Tim obtained access to the wind tunnels at the Air Force Academy. The take-away is how you might do the same with your local university. In Tim's case, he became a Student Launch Initiative (SLI) team mentor. He points out that it takes a skilled operator to tweak the dials on these things and to set up the test. The tunnels are both highly utilized and are not cheap to operate. Hence, you really must provide some value-added to the aeronautics program to have any hope of getting to use them.

He also reviews the types of tunnels that he saw in a walk-through of their Aeronautics Lab and gives a lay-person's description of how they work.  He saw 8 types including a hypersonic tunnel and a water tunnel. He noted that the test area of the hypersonic tunnel is a mere 1" square and the unit-under-test is exposed to more of a shock wave than a sustained wind.

Of all those tunnels, he was still only given access to one of three low speed 'student tunnels'. It has a top speed of 150 ft/s and they ran their tests at 57 ft/s to reduce the possibility that the model would re-kit and go through the fan blades: "This is a justifiable concern, as the models were made by gradeschool kids." LOL.

I can't remember whether I read this or it is my desire coming out, but I think there will be follow-on articles.