What is a wind tunnel?
And why are they so important
to flight and NASA?
In a wind tunnel, controlled air is blown over
an aircraft or spacecraft model.
At the Unitary Plan Wind Tunnel at NASA's Ames
Research Center in Silicon Valley,
researchers take readings of the airspeed, sound,
pressure and other vital details about
how air flows around the model.
This research helps everything from redesigning
of wings and tails, to developing control software,
to building accurate computer models.
Let's look at some of the key components that
make up a wind tunnel: 
Turning vanes
Three-stage compressor
11-foot test section 
A three-stage compressor, essentially a series of blades,
provides steady airflow over a fixed model
in the wind tunnel's test section.
 
Turning vanes smooth and direct
the flow of air over the model.
Within the test section, banks of cameras
and sensors record data.
The wind tunnels at NASA in Silicon Valley
will continue to test next generation aircraft
and spacecraft designs,
so the models of today will be the safe and
efficient transportation of tomorrow.
