An anonymous reader has sent me some cool pictures today. They show the Prandtl-Glauert condensation cloud phenomenon which accompanies aircrafts when they reach transonic speeds.
Transonic is an aeronautics term referring to a range of velocities just below and above the speed of sound (about 741 miles (1185 kilometers) per hour at sea level).
Four links are the following:
http://ChamorroBible.org/gpw/gpw-20040817.htm
http://ChamorroBible.org/gpw/gpw-20040818.htm
http://ChamorroBible.org/gpw/gpw-20041216.htm
http://ChamorroBible.org/gpw/gpw-20041217.htm
PhysOrg.com staff, thank you for posting the link to Dr. Mark S. Cramer's excellent Prandtl-Glauert condensation cloud tutorial and the four photo gallery links. Dr. Cramer is to be commended for explaining this fascinating phenomenon in language that are understandable to non-aerodynamicists (like me). And a thank you to the photographers and videographers who were in the right place at the right time to capture the phenomenon, plus, "Wow! (pause to regain composure) How did you do it? Can I fly with you next time?"
As I've read the tutorial and examined the photos and videos several questions come to mind. I hope you don't mind if I ask them here.
1. Are there any reliable online texts or research papers that more fully explain why the isoterms (see the section "Characteristic Cloud Shape" in Dr. Cramer's tutorial) have a conical shape?
2. Does the Prandtl-Glauert condensation cloud form once and "stay with" the aircraft or space vehicle? Or is it continuously created, i.e., as the jet/rocket moves through the air the cloud is disappearing and reappearing faster than the eye can detect?
3. In the Northrop Grumman Integrated Systems "B-2" video (link given in the four photo galleries as http://www.is.NorthropGrumman.com/videos/b2_tx.wmv ) why is the condensation cloud yellow? Why does it all of a sudden appear, sit on the flying wing for a few seconds, then
vanish like a light bulb goes off without electricity?
4. In Dr. Cramer's analysis of the "F-14 Condensation Cloud In Action" video (http://www.galleryoffluidmechanics.com/conden/mpegf14.htm, Video of F-14 Transonic Condensation, http://www.galleryoffluidmechanics.com/conden/f14.mpeg ), he observes that a
Here's my question without trying to sound scientific: Are there additional reasons why the Prandtl-Glauert cloud begins to form in front of and above the F-14?
5. If the aircraft remains in the transonic regime could the cloud continue to grow until it's extraordinarily huge?
6. Lastly, has the Prandtl-Glauert condensation cloud phenomenon been the subject of senior papers, theses, or dissertations?
Thanks to all, and to all U.S. citizens (I'm in that group), Happy 4th of July.
As I've read the tutorial and examined the photos and videos several questions come to mind. I hope you don't mind if I ask them here.
1. Are there any reliable online texts or research papers that more fully explain why the isoterms (see the section "Characteristic Cloud Shape" in Dr. Cramer's tutorial) have a conical shape?
2. Does the Prandtl-Glauert condensation cloud form once and "stay with" the aircraft or space vehicle? Or is it continuously created, i.e., as the jet/rocket moves through the air the cloud is disappearing and reappearing faster than the eye can detect?
3. In the Northrop Grumman Integrated Systems "B-2" video (link given in the four photo galleries as http://www.is.NorthropGrumman.com/videos/b2_tx.wmv ) why is the condensation cloud yellow? Why does it all of a sudden appear, sit on the flying wing for a few seconds, then
vanish like a light bulb goes off without electricity?
4. In Dr. Cramer's analysis of the "F-14 Condensation Cloud In Action" video (http://www.galleryoffluidmechanics.com/conden/mpegf14.htm, Video of F-14 Transonic Condensation, http://www.galleryoffluidmechanics.com/conden/f14.mpeg ), he observes that a
QUOTE
"second feature is the fact that the condensation first appears above the aircraft when the cloud reforms (and possibly when it forms). Of course, it is expected that the cloud should first form in the low pressure region which is necessarily above any lifting aircraft. However, the largest pressure perturbations are expected to be very near the aircraft. Hence the lowest pressures and therefore the cloud formation ought to be at the aircraft surface. We can give the usual atmospheric turbulence arguments, but without much conviction. Bob Harrington did point out that there may be flow disturbances generated by the ship which could cause an unanticipated Mach number or pressure distribution. I like this better than the generic turbulence argument."
Here's my question without trying to sound scientific: Are there additional reasons why the Prandtl-Glauert cloud begins to form in front of and above the F-14?
5. If the aircraft remains in the transonic regime could the cloud continue to grow until it's extraordinarily huge?
6. Lastly, has the Prandtl-Glauert condensation cloud phenomenon been the subject of senior papers, theses, or dissertations?
Thanks to all, and to all U.S. citizens (I'm in that group), Happy 4th of July.
Do you suppose there is a Prandlt-Glauert like "condensation cloud" for trans-light vehicles? What would that look like.
I know that Cherenkov radiation is the result of a particle traveling at the speed of light entering a denser medium and slowing to the speed of light in that medium. But what about a trans-light vehicle traveling through the more or less consistent vacuum of space?
I know that Cherenkov radiation is the result of a particle traveling at the speed of light entering a denser medium and slowing to the speed of light in that medium. But what about a trans-light vehicle traveling through the more or less consistent vacuum of space?
Cool Stuff, hey I am in NY and was wondering 2 things 1 - Are you guys going to have a show (like on G4TV or whatever)that I can get on my cable ? 2 - Kevin I was subscribed to, I believe it was "The Broken newsletter" and I don't get it any more, HELP woimer@netzero.net Also why is G4 in my opinion going like Ahhhhhh! ??? OK Peace Out, a fan, Paulie G. N.Y.C.
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I hate to say this but I know for a fact that one of those images is a hoax because the B-2 Stealth bomber is not capable of breaking the sound barrier. The F-22 Raptor is the first American aircraft that is both stealth and supersonic. The other pictures look real but that on of the B-2 Stealth Bomber is a fake.
I hate to say this but I know for a fact that one of those images is a hoax because the B-2 Stealth bomber is not capable of breaking the sound barrier. The F-22 Raptor is the first American aircraft that is both stealth and supersonic. The other pictures look real but that on of the B-2 Stealth Bomber is a fake.
the f-22 is not the first stealth aircraft to be supersonic. have you never heard of the "blackbird"
second point it's not a B-2 it's a B-1! pay attention please.
QUOTE (aaron+Apr 7 2006, 07:13 PM)
the f-22 is not the first stealth aircraft to be supersonic. have you never heard of the "blackbird"
The Blackbird wasn't true stealth. It just flew very high and very fast.
The Blackbird wasn't true stealth. It just flew very high and very fast.
QUOTE (nah+Jul 18 2005, 09:14 PM)
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I hate to say this but I know for a fact that one of those images is a hoax because the B-2 Stealth bomber is not capable of breaking the sound barrier. The F-22 Raptor is the first American aircraft that is both stealth and supersonic. The other pictures look real but that on of the B-2 Stealth Bomber is a fake.
Those pictures are real. If whatever aircraft were supersonic, the shockwave would begin at the nose of the aircraft. When air goes over a wing it speeds up, meaning that some parts of the flow around the craft are supersonic, eventhough the overall velocity is not. This is called transonic.
I hate to say this but I know for a fact that one of those images is a hoax because the B-2 Stealth bomber is not capable of breaking the sound barrier. The F-22 Raptor is the first American aircraft that is both stealth and supersonic. The other pictures look real but that on of the B-2 Stealth Bomber is a fake.
Those pictures are real. If whatever aircraft were supersonic, the shockwave would begin at the nose of the aircraft. When air goes over a wing it speeds up, meaning that some parts of the flow around the craft are supersonic, eventhough the overall velocity is not. This is called transonic.
How slow can a B2 fly? Does it have running lights on the front that flash in rotation?
How quiet is stealth?
How quiet is stealth?
date THURSDAY 14th september 2006i'm bob dylan's greatest bbc radio request writer "THE ANSWER MY FRIEND IS BLOWING IN THE WIND": say...med-gen-nick
i've seen bob dylan and his band live 9 times: i got back to the uk 20th april 2006 the aniversay of aldolf hitlers birthday: i've not got a visa back to see bob dylan in the usa LIVE since: got turned back at phillidelpia pa airport last year: they said i needed a visa to get back:
david christopher miedzianik rainmanhallelujah@hotmail.com
rotherham, south yorkshire, england, uk
20th april 2005 rather i got mixed up david miedzianik
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