Many of you have ben asking how the vapor cone pictured in the sound barrier post forms. This vapor cone is known as the Prandtl–Glauert Singularity or P.G. Singularity. It is sometimes also referred to as a shock collar or shock egg.
This effect can be seen anytime air is forced to rapidly expand and contract, such as during supersonic flight, and even during bomb explosions.
Apollo 11
Operation Crossroads
F-18
The cause of the PGS is complicated & still being studied, but in general what occurs is that rapid air pressure changes in the wake of the aircraft traveling at or above the speed of sound cause a temperature drop. If the tempertaure drops below the dew point, water vapor in the area condenses into water droplets. So the cone-shaped shock wave is, in simple terms, a cloud that forms in the region of the shock wave, much like the cloud-in-a-jar that you saw in 7th grade.
Source: Wikipedia.org
1 comment:
I knew that when the speed of sound was broken, the P.G. Singularity happened when a jet flew that fast, but I didn't know that it occurred with rockets and bomb explosions. That's very cool.
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