Baumgartner’s suit broke the sound barrier
Felix Baumgartner was the first to break the sound barrier in a free fall in 2012, when he jumped from a balloon at an altitude of almost 29 km. Now, scientists from the Technical University of Munich, Germany, have calculated how he could obtain such a falling velocity.
Baumgartner’s suit was a customised, tightfitting pressure suit, which was not particularly aerodynamic. Its surface was wrinkled just like an ordinary boiler suit.
It is complicated to predict what happens to the air currents around a falling body, when it approaches the speed of sound. The air behaves differently, and shock waves and turbulence develop, which function as an aerodynamic brake block. But according to the scientists’ calculations, Baumgartner’s wrinkled suit surface surprisingly did not slow him down, on the contrary. Whereas the brake block effect would double, if a smooth body fell in the same way, the effect remained almost unchanged in Baumgartner's case. The astonished scientists had to acknowledge that a surface with many indentations and bumps is useful, if you wish to fly at the speed of sound or faster.
The irregular surface is probably responsible for Baumgartner reaching the speed of sound much earlier than expected. The results are relevant to engineers working on future passenger planes, which will also be travelling at speeds close to that of sound.