Re: Interference pattern & jets

[ingep <ingep@ONLINE.NO>]

What is the physics behind these mach rings ? Any reference ?

Tony Wayne wrote:

> Each band is a speed of sound barrier. The rings you see are called
> "mach rings." The ring farthest away from the exhaust is "mach 1." The
> net closer ring to the exhaust is "mach 2." etc.
>
> ACSII Art...
>                       mach rings
>                             |
>                             |
>                             |
> =======+                   \_/
> *JET***| )  )  )   )   )    )      )
> =======+
>          |  |  |   |   |    |      |
>          |  |  |   |   |    |      |
> Mach #=> 7  6  5   4   3    2      1
>
> -tony
>
> Mike Wilson wrote:
> > <From: mwilson@colosys.net>
> >
> > In watching the military jets take of on the nightly news I notice the
> > exhaust exhibits patterns of bright exhaust, dark lines, bright exhaust,
> > etc.
> >
> > Am I seeing some type of interfernce pattern from light?
> > Am I seeing some type of combustion pattern (I can't imagine what)?
> > Why do I only notice it in military jets?
> > Does it depend on the use of after burners?
> >
> > Best Wishes,
> >
> > Mike Wilson
> > mwilson@colosys.net
> > Math/Science
> > West Grand HS
> > Kremmling, Colorado
>
> --
> ========================================================
> Tony Wayne                  Those that can, do.
> wayne@pen.k12.va.us         Those that understand, teach.