You know that picture of the F-14 with the condensation plume? (P.S. -- Hornit?)
dot @pcisysdotnet PatWeaver
symbols.
WHat am I missing?
Mark J. Cintala <Skyba...@mindspring.com> wrote in message
news:3839f0cb...@nntp.mindspring.com...
> Well, one of my friends at work got a copy of an MPEG, somehow, and he
> sent it to me. I just posted it on the alt.binaries.pictures.aviation
> NG.
>
> It's about a 1.3 MB download, but trust me -- it's worth it. Check
> out the apparent stability burp the Tomcat has as the condensation
> plume forms (in the slow-motion part).
>
> Just amazin'.
>
> Craters
>
> P.S. -- Hornit, did you ever get to do this in the '18??
Mark J. Cintala
Pete Marone
> sent it to me. I just posted it on the alt.binaries.pictures.aviation
> NG.
Interesting....this same MPG was being sent around Qualcomm today, too.
What a small world :)
Pete Marone
Mark J. Cintala
dot net> wrote:
>I go there and download the post and all I get is a bunch of gobbledegook
>symbols.
>WHat am I missing?
I guess it depends on the newsreader that you're using. With Agent,
for example, there's a "Launch binary attachment" command. I can't
really comment on other newsreaders, not having used them, but there's
probably a similar command in whatever one you use.
Anybody else?
Craters
Rez Manzoori
Thanks for posting it!
--
Rez Manzoori
(www.manzoori.demon.co.uk) - ICQ# 17763861
---------------------------
C:/DOS
C:/DOS/RUN
RUN/DOS/RUN
---------------------------
Mark J. Cintala <Skyba...@mindspring.com> wrote in message
news:3839f0cb...@nntp.mindspring.com...
> Well, one of my friends at work got a copy of an MPEG, somehow, and he
> sent it to me. I just posted it on the alt.binaries.pictures.aviation
> NG.
>
Raptor
> Does anybody out there have a website and wanna post it? If you can't
> get it from the alt.binaries.pictures.aviation NG, lemme know and I'll
> email it to you. (It's a 1.7MB file, so *please* don't ask me to
> email it, everybody!!!!)
I can. With the holiday coming up, I don't mind dogging my 56K modem
with an mpeg. When I see "getting new messages" take 5 minutes, I'll
know you sent it my way, and I'll put it up on my server.
--
Lynn Wallace http://www.xmission.com/~lawall
STEVE JOBS: We're better than you are. We've got better stuff.
BILL GATES: You don't get it, Steve. That doesn't matter!
"Pirates of Silicon Valley"
Photo Restoration done here:
http://www.xmission.com/~lawall/PhotoIndex.html
Mark J. Cintala
<R...@NOSPAM.Manzoori.Demon.Co.UK> wrote:
>Fantastic Movie Clip Mark!
>
>Thanks for posting it!
>
>--
>Rez Manzoori
>(www.manzoori.demon.co.uk) - ICQ# 17763861
>---------------------------
Hey, Rez --
No problemo, Sir! Very glad you liked it.
Shucks. That's the first binary I ever posted, and it worked.
What a thrill that was, lemme tell ya. Whooooeeeee. I'll bet it
couldn't come close to what the pilot of that sucker might have felt
when he had that little pitch excursion, though. Heh, heh.
Craters
Ricski
I got all excited about this clip... but I can't get it! My news server does
not carry the group and good old deja news is trying to tell me there has
only ever been one message posted to alt.binaries.pictures.aviation....
Is there an internet site that I could download it from? Any help would be
greatly appreciated,
Richard.
Darren Chriest
but any chance of a repost? Or can you tell us where you got it
from?
Mark J. Cintala
Oh, bloody 'ell. I guess I can try to repost it if that's not a
major affront to binary NG etiquette. Any of you guys know if that's
okay?
When I look at that NG, all four parts are there.
I wish I *could* give you another site, but I don't know if there is
or not -- I got it from a friend via email. I don't have a website,
so I can't post it myself.
Does anybody out there have a website and wanna post it? If you can't
get it from the alt.binaries.pictures.aviation NG, lemme know and I'll
email it to you. (It's a 1.7MB file, so *please* don't ask me to
email it, everybody!!!!)
Craters
Darren Chriest
> Oh, bloody 'ell. I guess I can try to repost it if that's not a
> major affront to binary NG etiquette. Any of you guys know if that's
> okay?
In a binary group binaries are encouraged. Reposts are normal, not all servers get all the
parts of a multi-part post. If your repost doesn't
propagate well I won't ask for another repost.
> When I look at that NG, all four parts are there.
Actually I use two different newsservers and both only list parts
2/4 and 4/4.
> I wish I *could* give you another site, but I don't know if there is
> or not -- I got it from a friend via email. I don't have a website,
> so I can't post it myself.
If you like you can send it to me in email to dchr...@home.com,
I got a big pipe. Of course more people will have more access to
it if you repost to the newsgroup.
> Does anybody out there have a website and wanna post it? If you can't
> get it from the alt.binaries.pictures.aviation NG, lemme know and I'll
> email it to you. (It's a 1.7MB file, so *please* don't ask me to
> email it, everybody!!!!)
Thanks Craters, i just gotta see this thing.
Darren Chriest
> I can. With the holiday coming up, I don't mind dogging my 56K modem
> with an mpeg. When I see "getting new messages" take 5 minutes, I'll
> know you sent it my way, and I'll put it up on my server.
Oh goody goody! :^)
Let us know when you got it up, ok Raptor?
Mark J. Cintala
Okay, Darren -- I'm reposting it there now. Hope it works for you
this time. If not, I'll send the sucker to you tomorrow, okay?
Thanks --
Craters
Darren Chriest
200 K/sec downloading the weather avi. It didn't work for some
reason but I sure got it fast! :^)
Looking foreward to the F-14 footage.
Mark J. Cintala
Just finished reposting it. My newsreader, at least, says that all
four parts are there. Good luck, and lemme know.
Craters
Darren Chriest
Darren Chriest
just be a distorted mess when the 14 passes (and probably was).
Darren Chriest
That would be just as good. Thanks though. I'll look for it.
Darren Chriest
Off to take a look at it now!! OhboyOhboyOhboyOhboyOhboy
Alex Pavloff
Cintala) wrote:
>Darren --
>
>Just finished reposting it. My newsreader, at least, says that all
>four parts are there. Good luck, and lemme know.
Got it now.......
Questions....... why are there two plumes at distinct intervals?
You've got one at one second into the pic, and another starting at 3
seconds.
Hrm.
Aerodynamacistabobber I ain't.
--
Alex Pavloff - xp...@earthlink.net
/loony/bin - where crazed programmers are sent
domain to reply!
>
Oh, please, please someone post it on their WWW/FTP site! My newsserver
doesn't carry this newsgroup!
Regards,
--
---------------------------------------------------------------------------
Victor Denisov Laboratory of Open Information Technologies
mailto:vden...@ur.enilder Computer Science Department
<Reverse domain to respond> Moscow State University
Don't waste your computer's idle cycles - join http://www.distributed.net!
Team HackZone - THE BEST Russian team in RC5-64 effort!
Raptor
I guess xmission deserves the credit. That avi is old, and I'm not
about to go about re-constructing it, assuming I could. Too bad though,
I have yet to see someone duplicate the process. Sorry about that.
See http://www.xmission.com/~lawall/fs14ss.mpg
It's worth the download.
Raptor
>
> Here's my take on it:
>
I saw a similar phenomena while peering inside the cowling of an MD-88 I
was riding from Dallas last summer. The air inside the intake flickered
rapidly into opacity on takeoff. The rapidity surprised me until I
recalled how quickly my breath condenses/evaporates on a cold day.
Mark J. Cintala
Victor --
Raptor has it, and he's going to try posting it on his website. I
don't know how long that might take him, but you might want to check
there occasionally. He's at
http://www.xmission.com/~lawall
Good luck -- I think he'll have it there in a little while.
Craters
Mark J. Cintala
Heh. Yeah, I can just *imagine* what it must have sounded like.
"Ooookay. THERE he is."
"Yeah, here he com---"
WHAMMMMMMMBOOOOMKERPOWWWWWWWWWW (fading ripping sound)
"My head! My head!!!"
"HEY, CHIEF -- YOUR EARS ARE BLEEDING! CAN YOU HEAR ME???"
(Klaxon noise) "Damage-control stations! Damage-control stations!
This is not a drill! This is not a drill!"
"Hey -- my %#@*! camera's busted!!!
Etc., etc. Heh, heh.
Craters
Mark J. Cintala
Alex --
I'm more into shocks in solids, but I'll hazard a guess. Ignorance of
anything never kept me from forcing my opinion on anybody.
Here's my take on it:
The condensation actually happens *behind* the shock front, because
that's where the decompression occurs. The shock compresses and heats
the air, but the decompression expands and cools it. When the latter
happens, sufficiently high humidity will enable the water to nucleate
as droplets, which is what we see. Since I doubt that the jet was
decelerating and accelerating so quickly over such a short distance
(i.e., to generate separate shock fronts), I would imagine that the
humidity was spotty enough to give the first burst of condensation
with a gap before the second one. (Actually, I guess there's even a
small, short burst right at the beginning of the slow-motion part.)
The shock front was still there, but enough humidity wasn't. In fact,
in my naive way of thinking, that phenomenon could happen even without
a shock discontinuity forming. Compression and decompression
obviously should happen even without a true shock wave forming, and if
the magnitude of the difference between the compression and
decompression were large enough, condensation should result.
The cloud doesn't persist because the overall air temperature was
below the dew point, so the droplets evaporated pretty fast.
So, there's my story. Anybody who knows what's really going on want
to comment?
Craters
P.S. -- Did you notice how the condensation persisted near the water
(after the first burst of condensation) even after the higher "cloud"
was gone? Probably because of the higher humidity in the microclimate
just above the water.
Darren Chriest
Darren Chriest
> I'm more into shocks in solids, but I'll hazard a guess.
mine had to study a lot of fluidics that dealt with stuff like this.
Mark J. Cintala
No -- impact cratering (unless that's what HVAC is). It's different
from that aerodynamic stuff.
Um, what *is* HVAC? The closest I can guess is "high-velocity air
conditioning."
Craters
David CL Francis
<Skyba...@mindspring.com> writes
>The condensation actually happens *behind* the shock front, because
>that's where the decompression occurs. The shock compresses and heats
>the air, but the decompression expands and cools it. When the latter
>happens, sufficiently high humidity will enable the water to nucleate
>as droplets, which is what we see. Since I doubt that the jet was
>decelerating and accelerating so quickly over such a short distance
>(i.e., to generate separate shock fronts), I would imagine that the
>humidity was spotty enough to give the first burst of condensation
>with a gap before the second one. (Actually, I guess there's even a
>small, short burst right at the beginning of the slow-motion part.)
>The shock front was still there, but enough humidity wasn't. In fact,
>in my naive way of thinking, that phenomenon could happen even without
>a shock discontinuity forming. Compression and decompression
>obviously should happen even without a true shock wave forming, and if
>the magnitude of the difference between the compression and
>decompression were large enough, condensation should result.
It is as well to remember that significant shock waves can develop on a
wing _before_ the aircraft as a whole reaches Mach One. The first shocks
usually appear over the middle of the wing where the airspeed is
highest. It depends on the aircraft and its shape etc., but the first
shocks may appear as low as M=0.8. In the days when I used to attend the
Farnborough Air Show almost every year I frequently saw condensation
clouds behind shock waves on aircraft that were well subsonic. A shock
wave ahead of wings and nose is a sure sign of supersonic flight but it
may not be visible.
At M=1.0 I would expect shock waves to be near the trailing edge of the
wing with another forming ahead of the wing. Swept wings raise the speed
at which this will occur significantly. However when the whole aircraft
is supersonic there will be a shock in front of the nose.
--
Francis E-Mail reply to <fli...@dclf.demon.co.uk>
Mark J. Cintala
<fli...@nospam.demon.co.uk> wrote:
>It is as well to remember that significant shock waves can develop on a
>wing _before_ the aircraft as a whole reaches Mach One. The first shocks
>usually appear over the middle of the wing where the airspeed is
>highest. It depends on the aircraft and its shape etc., but the first
>shocks may appear as low as M=0.8. In the days when I used to attend the
>Farnborough Air Show almost every year I frequently saw condensation
>clouds behind shock waves on aircraft that were well subsonic. A shock
>wave ahead of wings and nose is a sure sign of supersonic flight but it
>may not be visible.
>
>At M=1.0 I would expect shock waves to be near the trailing edge of the
>wing with another forming ahead of the wing. Swept wings raise the speed
>at which this will occur significantly. However when the whole aircraft
>is supersonic there will be a shock in front of the nose.
>--
>
>Francis E-Mail reply to <fli...@dclf.demon.co.uk>
>
David --
Does that mean, then, that the zone of condensation does *not*
necessarily imply a true shock front? I would think that a shock, no
matter where it's formed on the aircraft, would make a sonic boom.
I'm just wondering, because I've seen fighters at airshows do
low-level, high-speed passes (certainly near M=1) with no boom, but an
awful lot of noise nonetheless.
I'm glad you brought this up, because it's something that I've
wondered about for a while, but never asked. Unless relativity is
involved somehow (!!), the air over the top of the wings (or around
other parts of the aircraft) would have to exceed M=1 before the
aircraft itself did, wouldn't it? If so, why no sonic boom? Does the
shock get disrupted before it leaves the region immediately around the
aircraft or something like that?
Thanks!
Craters
Mark J. Cintala
Cintala) wrote:
>
>I'm glad you brought this up, because it's something that I've
>wondered about for a while, but never asked. Unless relativity is
>involved somehow (!!), the air over the top of the wings (or around
>other parts of the aircraft) would have to exceed M=1 before the
>aircraft itself did, wouldn't it? If so, why no sonic boom? Does the
>shock get disrupted before it leaves the region immediately around the
>aircraft or something like that?
>
>Thanks!
>
>Craters
David --
Sorry about this part and its redundancy relative to your original
comments. I was doing a stream-of-consciousness thing there. The
relevant part is in the last two questoins.
Thanks --
Craters
David CL Francis
In article <383f269e...@nntp.mindspring.com>, Mark J. Cintala
<Skyba...@mindspring.com> writes
>
>Does that mean, then, that the zone of condensation does *not*
>necessarily imply a true shock front?
Correct. I was watching a Discovery programme the other night and it
showed an F14 taking off from a carrier. As the aircraft pulled its nose
up as it left the deck (almost certainly at less than 200 knots) a brief
condensation was clearly visible over the wing.
> I would think that a shock, no
>matter where it's formed on the aircraft, would make a sonic boom.
Nope. The boom is only heard if the shock passes your ear. In the case
of small shocks formed locally they are surrounded by sub sonic air and
only extend a short way from the wing. No boom to be heard.
>I'm just wondering, because I've seen fighters at airshows do
>low-level, high-speed passes (certainly near M=1) with no boom, but an
>awful lot of noise nonetheless.
>
So have I!
>I'm glad you brought this up, because it's something that I've
>wondered about for a while, but never asked. Unless relativity is
>involved somehow (!!), the air over the top of the wings (or around
>other parts of the aircraft) would have to exceed M=1 before the
>aircraft itself did, wouldn't it?
Yes it would and it can. It can happen over the top of a canopy as well.
However swept back wings delay the effect. Because of the shape of the
wing section and the fact that it is generating lift the air speeds up
over the top of the wing surface. It will reach Mach 1 when the aircraft
is flying at perhaps 0.8M. The thicker the wing the earlier the shock
will appear on the top surface particularly. As speed changes those
local shocks move gradually further back along across the wing.
> If so, why no sonic boom? Does the
>shock get disrupted before it leaves the region immediately around the
>aircraft or something like that?
>
Yes, what happens is the flow close to the wing goes supersonic but as
you go out from the wing surface the velocity falls subsonic and the
shock peters out. Also because these early shocks are almost normal (at
right angles to the air flow the air flow after the shock is also
subsonic.
>Thanks!
You are welcome
David
Mark J. Cintala
Thank you very much for the wisdom! Everything you said makes eminent
sense, confirming some of my suspicions, crushing others, and raising
new ones.
It's nice to be able to invoke the Voice of Experience around here!
Craters