Supersonic wind tunnels are rather simple (though very expensive) to build. When their air moves well above the speed of sound, it passes through the experimental chamber in a smooth, even stream. "Transonic" tunnels (close to the speed of sound) are much more difficult. At this critical speed, very important in the study of aerodynamics, the tunnel tends to "choke." Shock waves form inside it, making accurate experiments difficult.
To get around this hurdle, the National Advisory Committee for Aeronautics has been developing "gravity propelled" models to be dropped from airplanes high above...
To continue reading:
or
Log-In
