Comments on: Why is there a disk shaped misty shroud around a jet when it breaks the sound barrier?

By: freedomisbetter

freedomisbetter — Fri, 10 Jul 2009 15:50:59 +0000

The sound barrier is only one. The physics use Mach number: if a plane goes at twice the sound speed, you can say its speed is Mach 2. Is a plane flight very fast, you can say that there are a thermal barrier (The temperature due to air friction can damage some parts of the plane.) But this thermal barrier is not a specific number. When the jet breaks the sound barrier (Mach 1), the patterns of pressure in the wings and in the nose suddenly changes. The decompression of the air can produce water condensation (the misty disk you saw)
References :

By: jackdaniels165

jackdaniels165 — Fri, 10 Jul 2009 15:28:59 +0000

Just one wall. There aren’t an infiniate number of sound barriers, just the one. I don’t know about your black smoke question though.
References :
Science class

By: DT89ACE

DT89ACE — Fri, 10 Jul 2009 15:23:59 +0000

There is no visible sound wall and that moisture cloud happens just as easily when a plane is sub-sonic - its a result of moisture in the air.

I’ll probably get a thumbs down, by someone saying other wise because that it was they’ve been mislead to believe, but that conical shaped cloud is simply moisture - its condensation forming a cloud around the plane as its pushes through the air. The conditions have to be right, but thats all there is to it - just like contrails. If the condition is right you’ll get them, if not you won’t.

The sound barrier is simply a number. Its the speed at which sound travels - when something goes super-sonic, it is moving faster than sound, therefore it creates a sonic boom. Once the speed of sound is exceeded there is no additional sound that occurs (or any walls) as a result of going Mach 2 or Mach 3, etc.

For the record, this also applies to bullets. On most days, you’ll never see a trail from a super-sonic or any bullet fired from a firearm. A sonic boom follows the bullet downrange as far as it remains super-sonic. When the conditions are right, you can see a trail of a bullet fired - this applies more at long ranges through a scope. With the naked eye its very hard.
References :