- #71
FredGarvin
Science Advisor
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That looks really cool Wolram. I would love to fly in any of those. I think the Buccanneer would be my first choice. I love that era of aircraft.
FredGarvin said:I believe September is the end...sigh.
http://usmilitary.about.com/od/navyweapons/a/f14lastflight.htm
http://www.military.com/features/0,15240,94327,00.html
http://www.military.com/NewsContent/0,13319,90808,00.html
3trQN said:
a source said:The clouds formed by the Prandtl-Glauert singularity are due to the near-sonic amplification of the pressure and temperature perturbations which naturally occur whenever air passes over any bump or object. Thus, an aircraft can fly at one-half or twice the speed of sound and generate no clouds. However, if the same aircraft flies at 0.95 or 1.05 times the speed of sound, the amplification implicit in (Pg2) may be enough to cause condensation in the low-pressure, low-temperature portions of the flow.
So, in terms of dispelling this myth, is it safe to say that this is NOT necessarily a pic of plane breaking the sound barrier?FredGarvin said:Yeah. We've talked about that one before. Clausius pointed that out a while back. The aircraft doesn't need to be supersonic ...
FredGarvin said:it does have to have established trans sonic speeds..."
So, in terms of dispelling this myth, is it safe to say that this is NOT necessarily a pic of plane breaking the sound barrier?
This leads me to believe that I'm just splitting hairs - that, give or take .05 Mach, this IS, for all intents and purposes, a pic of a plane breaking the sound barrier.
Finally, it should be clear that Prandtl-Glauert condensation has nothing to do with "breaking the sound barrier" and is not a Star Trek-like "burst" through Mach one. An aircraft can generate a Prandtl-Glauert condensation cloud without ever exceeding the speed of sound.
Somewhere there is a video of that - an F-14, I think, flying past a carrier at just under Mach 1, and as it flies through regions of slightly higher or lower humidity (remember, over the ocean, the air is always near saturation), the cloud comes and goes.cyrusabdollahi said:Yes, it is in the transonic region, that's all. Meaning the airplane is between mach 0.95-1.01 (ish) roughly. (It may or may not be breaking the sound barrier with the cloud formation)
While I can't vouch for the speed, I can say that I've never seen a .22 rimfire bullet that looked like that. The closest that I've run across were Hornets or Yellowjackets, both of which are definitely supersonic. And I've seen very similar pictures where the bullet is clearly identifiable as a spire-point boattail hunting round. :tongue:berkeman said:Looks like a .22 at around 500fps.