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Newbie Joined: Feb 27, 2005 Posts: 14 Status: Offline

Hey everyone, this may have been posted on here before, but what is the fuzziness underneath the Raptor starting at 1:02 in the linked video? I apologize if this was asked before, but searching for fuzz, fuzzy, fuzziness, blurry, blurriness and censor in the F-22 forum didn't turn up anything.

I have seen that "fuzz" clip on the History Channel and other places, so I was just wondering.

http://www.youtube.com/watch?v=KRaOcwhijes&NR=1

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May have simply been condensation forming from a small shock wave or something at that particular part of the airframe (looked like it was on the RH wingtip to me).

i guess we beat the russians to plasma stealth Thumb

Elite 1K Joined: Jul 20, 2005 Posts: 1035 Status: Offline

Ectoplasm?? I hope your not trying to be serious.......

"The Prandtl-Glauert singularity (sometimes referred to as a "vapor cone"), is the point at which a sudden drop in air pressure occurs, and is generally accepted as the cause of the visible condensation cloud that often surrounds an aircraft travelling at transonic speeds, though there remains some debate. It is an example of a mathematical singularity in aerodynamics.

One view of this phenomenon is that it exhibits the effect of compressibility and the so-called "N-wave". The N-wave is the time variant pressure profile seen by a static observer as a sonic compression wave passes. The overall three-dimensional shock wave is in the form of a cone with its apex at the supersonic aircraft. This wave follows the aircraft. The pressure profile of the wave is composed of a leading compression component (the initial upward stroke of the "N"), followed by a pressure descent forming a rarefaction of the air (the downward diagonal of the "N"), followed by a return to the normal ambient pressure (the final upward stroke of the "N"). The rarefaction may be thought of as the "rebounding" of the compression due to inertial effects. These condensation clouds, also known as "shock-collars" or "shock eggs," are frequently seen during space-shuttle launches around 25 to 33 seconds after launch when the vehicle passes through the area of maximum dynamic air-pressure, or max Q.

Since heat does not leave the affected air mass, this change of pressure is adiabatic, with an associated change of temperature. In humid air, the drop in temperature in the most rarefied portion of the shock wave (close to the aircraft) can bring the air temperature below its dew point, at which moisture condenses to form a visible cloud of microscopic water droplets. Since the pressure effect of the wave is reduced by its expansion (the same pressure effect is spread over a larger radius), the vapor effect also has a limited radius. Such vapor can also be seen in low pressure regions during high–g subsonic maneuvers in humid conditions.

Prandtl-Glauert singularity effects can be readily observed on a humid day by successfully cracking a whip. A visible cloud is produced at the point where the tip of the whip goes transonic."

Elite 1K Joined: Jul 20, 2005 Posts: 1035 Status: Offline

It was more of a question than trying to be condescending...I didn't write them and I guess the paste didn't get everything...I did include the quotes though. I got it from a fluid dynamics website but you can find it all over the net. Roll your eyes all you want ectoplasm!

If it was "Ectoplasm", wouldn't it be green.... it was in Ghostbusters

Smitty

Gotta love wikipedia for that reason.

Here is Checks' post, as I understood it:

Quote:

Ectoplasm?? I hope your not trying to be serious.......

"$*$(#)_(!&+%&#()N(&!@&#(*(_)!(@)*(#)&!()@$&^%!^)(^$&^*()(%^
&&$^(*&%^&$&^(*&()&*_)(*^^&*%&*^&*(&&)(_)(*()&^*&TGHO &YR%#^E& ^&%$^%RY*^&%*&)(^%&%^(%(%&^*(_Y*(&^()&_(U)*(%
%^$$@##!$#@%^&RT&*(YUHKM:? Razz

I()&*&*%*(%*&_)()++))*^^$$#$
@!@!^#$@$#%$^&%&%^$*$^%&(*&%&&% transonic speeds, &*$@*()!!()*&*!^&%#^&%~^%)&^*&()+>?<M:"}{)_)@*()!&*(YHIWQ+
__+)_)+_)_)+_)_)+)_+DJIHWUYUQWO&^#@!))(@&*^)_

One &@(!)_*@#()&!*@^$*&(_!@#*&$!*(!@$*@&_!()*+($*(!&)(*!BN()__!@()&#
*&*!@(_&#*@(_! the $#*@()!_(@*#()@!&*$(@! YDH_(WNM(*!()@*#(_&!*@_$&(&@*$^@*(&_@*#_~_+)*~!^&(*$#@!><"::
S"{$@!><?!@#!%)*)(!&$*(@!@)(&$*(!&*%*&#()!_*)(&$*(@&_@(&*$(*@$*
@_*$**()_&$*!_.............

The rest of it read about the same to me Shrug

Senior member Joined: Jul 01, 2007 Posts: 368

You guys are far too emotionally sensitive.

Active Member Joined: Nov 22, 2004 Posts: 134

SnakeHandler wrote:

You guys are far too emotionally sensitive.

How DARE you say such hurtful words?! Shocked

You take that back right now, you old meanie, or I'm gonna CRY! Crying or Very sad

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Fuzziness under Raptor