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Jet engine sim for testing 9/11 planes

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posted on May, 9 2008 @ 09:35 PM
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reply to post by _Del_
 


I really do hope that you're kidding here.




posted on May, 9 2008 @ 09:43 PM
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reply to post by HLR53K
 


I think it's perfectly reasonable in the absence of an official report to believe the least likely of several scenarios. Particularly if it would otherwise contradict my position. Until I see an official report confirming the make up of the dust, I suspect I will argue for the least likely of the scenarios; Sir William of Ockham be damned.



posted on May, 9 2008 @ 09:45 PM
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Originally posted by HLR53K
[I have asked you to post your source numerous times, but you have yet to do that. I will gladly take a look at the academics of that site and its statement.


It has been posted since the very first page. You really should learn to read post.

www.earth-citizens.net...

What happens if the plane is moving at high speed? At sea level, and 400 mph airspeed -- the exhaust velocity declines only by the tiniest smidgen, to 2242 feet per second. That's relative to the velocity of the plane, so the ground speed of the exhaust would be reduced to about 1100 mph -- which is still plenty fast enough to send Probst spinning like a pinball. Not to mention the issue of wake turbulence and ground effect, as the weight of an 80-ton jetliner must be supported by exerting downward pressure on the air squeezed between its wings and the ground.



Jerry Russel and Richard Stanley bring some precisions : "the engine exhaust velocity, right at the exit nozzle, is 2281 feet/sec (that is, about 1500 mph)." I think that this should be refined in two ways :

Modern jet engines, like on B 757s, have a double exhaust flux : hot gases, coming out from the high pressure stage on the center, cold air pushed by the front low pressure fan at the exterior. These two fluxes have different speeds. The central hot flux speed is something like two times the speed of the annular cold flux which surrounds it. This later cold flux speed is approximately the full speed of the aircraft, i.e. something like 650 mph (near sound speed).

There are, near the exhaust, two turbulence zones created by the mix of gases : one at the hot flux / cold flux interface zone, and one at the cold flux / exterior air interface zone. Behind the aircraft, (say ~30 ft behind the engine) the hot and cold fluxes mix. Their speed decrease because they spread in a growing section cone. Thus it is reasonnable to think that when this cone met the ground on rd 27, the average relative speed - regarding to the plane - of the turbulent gases was something like 500 mph, and not 1500 !




The plane was said to fly at ~350 mph when it hit the Pentagon. Thus, I think that when the cars on rd 27 were blown by the blast of the engines, this blast had a relative speed of ~150 mph regarding to the ground. As explained above, this did not last a long time. Cars were shocked and moved a little sidely. As they were all stopped or nearly stopped in a traffic jam, this did not cause any accident by itself.





Some witnesses who were inside cars on rd 27 said that their car was rocked and pushed sidely on the road. This limited effect is coherent with the overfly of a Boeing 757 plane flying at approximately 350 mph with engines at full throttle. The case presented in the video quoted above is completely different. This "no cars were pushed over the safety barrier of rd 27" statement is by no way an argument to say that the Pentagon was not hit by a B 757.



posted on May, 9 2008 @ 10:24 PM
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reply to post by ULTIMA1
 


It's not a matter of my learning to read posts (I actually suggest you reading some of mine). If you would have just nicely said you were referring to the post on the first page, then I would have gone there myself.

Instead, you choose to insult me. And you wonder why no one takes you seriously...


Anyway, I will read through the whole thing now.



posted on May, 9 2008 @ 10:34 PM
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It was a very interesting read. It's not too specific in the academic details. I am willing to give you that the cars would have been rocked IF they were directly behind the engine nozzles.



posted on May, 9 2008 @ 10:37 PM
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Originally posted by HLR53K
Instead, you choose to insult me. And you wonder why no one takes you seriously...
.


Only because i have been insulted since day 1 just for trying to find the truth and not jsut believing what we have been told.



posted on May, 9 2008 @ 10:41 PM
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Originally posted by ULTIMA1

Only because i have been insulted since day 1 just for trying to find the truth and not jsut believing what we have been told.


Now that I have viewed your site. How's about you look at my posts and see how much merit there is there.

I just pulled out my aerodynamics books and I will see if there is an equation or two that relate velocity to the strength of the wingtip vortices.



posted on May, 9 2008 @ 11:00 PM
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Having read this again, I'm left with the same unanswered questions. I apologize in advance for the large blocks of quoted texts I'm about to use, but it is integral to understanding the article you linked to.

One half of your material is from Jerry Russel and Richard Stanley. The other half is from someone refuting them. For example:


What happens if the plane is moving at high speed? At sea level, and 400 mph airspeed -- the exhaust velocity declines only by the tiniest smidgen, to 2242 feet per second. That's relative to the velocity of the plane, so the ground speed of the exhaust would be reduced to about 1100 mph -- which is still plenty fast enough to send Probst spinning like a pinball. Not to mention the issue of wake turbulence and ground effect, as the weight of an 80-ton jetliner must be supported by exerting downward pressure on the air squeezed between its wings and the ground.




Jerry Russel and Richard Stanley bring some precisions : "the engine exhaust velocity, right at the exit nozzle, is 2281 feet/sec (that is, about 1500 mph)." I think that this should be refined in two ways :

Modern jet engines, like on B 757s, have a double exhaust flux : hot gases, coming out from the high pressure stage on the center, cold air pushed by the front low pressure fan at the exterior. These two fluxes have different speeds. The central hot flux speed is something like two times the speed of the annular cold flux which surrounds it. This later cold flux speed is approximately the full speed of the aircraft, i.e. something like 650 mph (near sound speed).

There are, near the exhaust, two turbulence zones created by the mix of gases : one at the hot flux / cold flux interface zone, and one at the cold flux / exterior air interface zone. Behind the aircraft, (say ~30 ft behind the engine) the hot and cold fluxes mix. Their speed decrease because they spread in a growing section cone. Thus it is reasonnable to think that when this cone met the ground on rd 27, the average relative speed - regarding to the plane - of the turbulent gases was something like 500 mph, and not 1500 !


These are statements made by Jerry Russel and Richard Stanley on their page here: www.911-strike.com...

The following statements are made by the author (Jean-Pierre Desmoulins) of the site you are citing from here: www.earth-citizens.net... or his home here: www.earth-citizens.net...



The plane was said to fly at ~350 mph when it hit the Pentagon. Thus, I think that when the cars on rd 27 were blown by the blast of the engines, this blast had a relative speed of ~150 mph regarding to the ground. As explained above, this did not last a long time. Cars were shocked and moved a little sidely. As they were all stopped or nearly stopped in a traffic jam, this did not cause any accident by itself.
Some witnesses who were inside cars on rd 27 said that their car was rocked and pushed sidely on the road. This limited effect is coherent with the overfly of a Boeing 757 plane flying at approximately 350 mph with engines at full throttle. The case presented in the video quoted above is completely different. This "no cars were pushed over the safety barrier of rd 27" statement is by no way an argument to say that the Pentagon was not hit by a B 757.



The irony here is that the later part by Jean-Pierre Desmoulins is to refute Stanley and Russel, but you are using them as a coherent argument togther. You have linked to a page claiming it supports your theory because you did not properly read the content, and instead quote mined thinking it would strengthen your argument. Desmoulins has presents two theories of his own, but that doesn't mean the quotations you cited are not at odds with eachother.
After examining the evidence, the scenario Jean-Pierre now proposes as the most probable is that American Airlines Flight 77, a Boeing 757 with around 60 people onboard, crashed into the west aisle of the pentagon on 911. "Jean-Pierre believes that the plane was either piloted by hijacker, Hani Hanjour, or it was remotely piloted with a technology like “Global Hawk,” but has no facts to prove either hypotheses." Atleast he's honest.

You can't quote both sides of a dispute and say they are both proof of one side (whichever side you are attempting to prove). This and your linking to an Associated Press article and maintaining it was a FEMA report, even after I pointed it out to you are typical of the obstacles you have to overcome before I can take you or your theory seriously. Even if your theory is true, you are doing it no favours by presenting it in a dishonest or incoherent manner.


[edit on 9-5-2008 by _Del_]



posted on May, 9 2008 @ 11:49 PM
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In the course of reading through my books, I remembered the Reynolds Number, from the Navier-Stokes equation.

This is a ratio of inertial forces to viscous forces. Another way to think of this is the air pressure force on the surface of an object divided by the shear force felt by the surface of the object.

The equation is:

Re = (ro*v*x) / mu

Re: Reynolds Number
v: Velocity
x: Length of surface
mu: Fluid viscosity

There are two regions, laminar and turbulent flow. The higher the Reynolds Number, the more turbulent the flow becomes. The more turbulent the flow, the higher number of eddies and vortices present. The transition point that lies between the two regions is roughly a Reynolds Number of 2,500.

As you can see from the equation, the velocity of the flow lies in the numerator. Thus, as velocity increases, the Reynolds Number increases and there is more turbulence in the flow.

This can be found in chapters 1, 4, 17, 1, and 19 of "Fundamentals of Aerodynamics" by John D. Anderson, Jr., 4th edition.


This site gives a nice overview and derivation of the Reynolds Number, along with an applet for you to see the change in Reynolds Number at a given altitude, velocity, and surface length.

www.grc.nasa.gov...

At an altitude of 60 feet and a wing chord of 20 feet (somewhere between the root and the tip; the B757 has a root chord of ~27 feet) a velocity of 400 mph gives a Re = 76,945,405. Keeping the altitude and wing chord the same and increasing the velocity to 440 mph gives a Re = 84,639,945. A huge, 7,694,540 increase.

I used the chord because the airfoil at that location does have a curve, so the exact length won't be known unless someone actually goes and measures it.


I do believe this ends the wake turbulence debate once and for all. The faster an object moves through the air the greater the turbulence behind it.

[edit on 10-5-2008 by HLR53K]



posted on May, 10 2008 @ 01:08 AM
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reply to post by HLR53K
 


Big 'ole star for you, HLR, for remembering the Reynolds number!!!!

I never got into the engineering aspects of aerodynamics (fond of saying I just fly the derned things).....but I am old enough to remember the introduction of the Cessna Cardinal, and how Cessna promoted its wing as 'laminar flow'.

Of course, they had been building the C210 for some years, and used a similar technique....flush rivets, no struts (strong wingbox on top of the cabin, etc....) in the wing design.....but the Cardinal was marketed as an entry-level, lower-priced (read it as affordable) alternative to the C172....actually, a step up from the C172, before the C182 (It was designated the C177)

Another innovation.....well not innovative, but a break from traditional Cessna design, was the 'flying stabilator'....Piper did it as well, not sure who did it first.....Piper's was in the Cherokee Six, if memory serves....

(a 'flying' stabilator means that the entire horizontal stabilizer moves, in response to the control column inputs. It is hinged at the part of the thickest chord, of the airfoil....it was thought to be more efficient....less drag....than the traditional fixed Horiz Stab/Elevator arrangement).

The airplanes actually flew very well, and had a rakish (sexy?) look....The Cardinal was succesful enough that a version with retractable gear was offered, as well....a 'poor man's Cessna 210', in a way.

See...the original C177 had a 180 horsepower Lycoming, normally aspirated, with a carbuerater. The C177RG was offered with a fuel-injected Lycoming.....can't remember the horsepower, but it was a step up. The C210 had the Continental engine....more expensive, and fuel-injected....six-cylinder, as opposed to the Lycomings four cylinders....the C210 had, maybe 310 horsepower? Again, I'm going from memory, ya'll can fact check and beat me up later......

So, on to the OP of this thread, with the background I just provided.....I did that for the various Private Pilots who may be in the audience.....who are old enough to remember those airplanes.....they still exist, on the used-airplane market, BTW....

This is stuff I know, because I lived it....even if the memory is vague from 30 years ago.

But, my experience in real jets.....the ones you depend upon to go see Grandma....is much more recent. The only Airbus Model I've flown is the old A-300 dash 200.....not a 'side-stick' control, no advanced avionics....basically DC-10 era (early to late 1970s) tech.

The 'glass cockpit' technology began to be introduced, in the commercial airplanes, around the late 1980s, early 1990s. It was new, and innovative.....and strongly opposed by many of the 'old timers'.....

However, the EFIS (Electronic Flight Information Screen) technology [glass cockpit] provides so much more information, once a pilot adjusts, and learns how to interpret it, that it has resulted in a revolution in efficiency and safety.

OK.....I've been lecturing, sorry. I tend to do that....it seems necessary, though, to help provide groundwork in order to educate.

Just reminding myself, this thread is about 9/11 conspiracies.....and the Jet engine sim for testing 9/11 planes.......

Well, I've posted, already, up above, that jet engines don't immediately disentegrate the second they go 'over-temp'......if so, I'd not wnat to fly that engine on MY airplane!!! Because, in an emergency, I'd want the 150% over-temp protection, built-in, to get us safely back on the graound!!

Yeah, the engine would be trashed.....but if it keeps running until we land, it's worth the cost!!!! And, that is how they are designed....you burn 'em up, it costs money.....so you don't over-temp them in normal operations.....because they should have a lifespan (equals money....and safety, they are connected).....

WW



posted on May, 10 2008 @ 07:04 AM
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Originally posted by _Del_
After examining the evidence, the scenario Jean-Pierre now proposes as the most probable is that American Airlines Flight 77, a Boeing 757 with around 60 people onboard, crashed into the west aisle of the pentagon on 911.


Gee, all that and no evidnece to dispute the jet blast rocked the cars on the raod.

Still proving my point about believers.



posted on May, 10 2008 @ 07:09 AM
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Originally posted by HLR53K
I do believe this ends the wake turbulence debate once and for all. The faster an object moves through the air the greater the turbulence behind it.


Who was debating wake turbulence? I posted a source about about speed and turbunce.

IN fact when i first brought up wake turbulence on another thread when i first came into this forum most of the believers siad no.

Now that i bring up jet blast the believers state NO it was wake turbulence.

I wish the believers would make up thier minds, they are almost as bad as NIST for changing thier stories.



posted on May, 10 2008 @ 07:12 AM
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Originally posted by weedwhacker
I never got into the engineering aspects of aerodynamics (fond of saying I just fly the derned things).....


Yes, as i learned in the Air Force most pilots only know what their instruments tell them they do not know about the actual workings of the plane.



posted on May, 10 2008 @ 07:23 AM
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reply to post by ULTIMA1
 


Let me refresh everyone's mind who's viewing and posting in this thread. On 5/6/2008 at 6:01 PM, you posted this:


Originally posted by ULTIMA1

Well as stated wake turbulence decrease as speed increases.

I have only found the 1 good source that talks about jet blast from a plane flying over cars or obsticles.


Now, I do believe that is you starting a debate on wake turbulence. In my post above, I clearly prove using aerodynamic principles and one of the most important principles of fluid mechanics that as velocity increases, wake turbulence increases.

Everyone here can see that you have been caught in a dead lie and that you have been proven completely wrong about your notion of wake turbulence. Why can't you just learn something from this and be man enough to admit you were wrong?

DO NOT confuse me with your notion of "believers" flipping their minds. I have been consistant with my statement that wake turbulence or whatever kind of turbulence in general increases as the velocity of an object traveling through a fluid increases.

[edit on 10-5-2008 by HLR53K]



posted on May, 10 2008 @ 07:40 AM
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Originally posted by HLR53K
Everyone here can see that you have been caught in a dead lie and that you have been proven completely wrong about your notion of wake turbulence.


So i guess you lied when you posted this? Now who is caught in a lie?

posted on 7-5-2008 @ 09:52

Originally posted by HLR53K
Of course an airplane flying straight and level will create less wake than an airplane with a high (or low) AoA.



[edit on 10-5-2008 by ULTIMA1]



posted on May, 10 2008 @ 07:47 AM
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reply to post by ULTIMA1
 


That's not a lie. An airplane flying straight and level will have less turbulence than an airplane flying at a high or low AoA.

But if you compare an airplane that was flying in either one of those configurations (straight and level or at an AoA) at a lower velocity to the same configuration at a higher velocity, the one at the higher velocity will have a larger turbulence.

To clarify:
An airplane flying at an AoA of +5 degrees at 450 mph will have less turbulence than the same airplane flying at an AoA of +5 degrees at 500 mph.

As I have explained, in your statement, you did not specify a change in AoA, but rather a change in speed that changes the turbulence. To find the direct connection between speed and turbulence, you have to keep all the other variables constant (that includes AoA).

Thus, the Reynolds Number of a flow to relate airsteam velocity to the amount of turbulence holds.

[edit on 10-5-2008 by HLR53K]



posted on May, 10 2008 @ 07:56 AM
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Originally posted by HLR53K
That's not a lie. An airplane flying straight and level will have less turbulence than an airplane flying at a high or low AoA.


Oh, ok so that right but the speed part is not right.

I guess this must be a lie too then.


posted on 27-4-2008 @ 02:53
ULTIMA....yes, I lready posted this.

The vortices are strongest when 'slow and heavy'

"Slow" only occurs in the Landing Configuration. 'Heavy' refers to any airplane that is 'capable' of a GTOW of 300,000 lbs or more. The B757-200 is not designated a 'heavy' (the B757-300 is) but it is treated, by ATC, with the same separation standards as a 'heavy', bucuase it has been determined that WHEN IN THE LANDING CONFIGURATION, the B757-200 exhibits a wake turbelence vortex, from each wingtip, similar to airplnes of ahigher weight ctegory.



posted on May, 10 2008 @ 08:06 AM
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reply to post by ULTIMA1
 


The thing I think everyone's doing here is comparing an airplane in its landing configuration with its cruising configuration. AoA is another major factor because, as I've said, it increases the cross-sectional surface area facing the airstream.

Ok, I want to admend my statement a little bit. There will be a point when an airplane flying straight and level will create turbulence that's greater than the same one with a +/- AoA. However, that would involve a really high velocity that most conventional airplanes won't be able to reach, so for all intensive purposes, the original statement still stands as a general overview.

If I remember correctly, I believe the unique case of the B757 producing much larger turbulence was due to the choice of airfoil for the wing. I can't remember the exact details, but it definitely has to do with the airfoil's camber to try and get more lift out of the wing.

[edit on 10-5-2008 by HLR53K]



posted on May, 10 2008 @ 08:14 AM
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Ok, the B757 uses an internal designation for its airfoils (BAC or TR series), so it's not readily available.

However, I do know that it's a supercritical airfoil, which has a greater camber in it than a conventional airfoil. This leads to better lift performance in the Mach .7 to 1.2 range.

As stated before, and increase in lift also generates a larger wake turbulence.



posted on May, 10 2008 @ 08:18 AM
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Originally posted by HLR53K
The thing I think everyone's doing here is comparing an airplane in its landing configuration with its cruising configuration.


Even the FAA agrees that SPEED plays a part in strength of turbulence (as i have stated)

www.faa.gov...

The strength of the vortex is governed by the weight, speed, and shape of the wing of the generating aircraft. The vortex characteristics of any given aircraft can also be changed by extension of flaps or other wing configuring devices as well as by change in speed. However, as the basic factor is weight, the vortex strength increases proportionately. Peak vortex tangential speeds exceeding 300 feet per second have been recorded. The greatest vortex strength occurs when the generating aircraft is HEAVY, CLEAN, and SLOW.



[edit on 10-5-2008 by ULTIMA1]



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