There’s a manned aircraft demonstrator built by Burt Rutan, has a 4 chamber PDE on it. On the USAF Propulsion Directorate website page there’s a gallery of videos that detail the operating of PDE’s. Including engine runs.

http://www.pr.afrl.af.mil/divisions/prt/pde/Videos/videos.html

Found the link.

Could be for EM hardness testing…..i know the US has an ENORMOUS wooden structure out in the west that they put jets on and charge up a big system and shock the whole plane to test the electronics. But it might not be related at all.

To the pics posted above, they’re not from a widebody commercial airliner, i saw them in Flight International and they belong to a much smaller small jet commuter aircraft, i didn’t buy it though so i can’t follow up on them properly.

they’re in the dozens of megs each that’s why, i don’t think this forum has that kind of attachment accomidation.

The electrical properties of RAM itself varies with temperature, although it must be said that aero heating at supercruise gives it an equivelent skin temperature of the aircraft sitting on the ramp on a hot day, as the ambient air temp up at altitude is quite cold. I would imagine a lot of research has gone into stabilizing the electrical properties of RAM and RAS since the F-117.

The next outing

Comon you also said youre pretty wrong “facts”, hes the next after you :rolleyes:????, dont be arrogant…..

but because the TV nozzles take work out of the horizontal slabs in pitch leaving them do do more for roll control

Comon thats is not a big difference…..

A MiG-25 is subsonic at sea level

Comon another myth…….

horizontal stress is not a big challenge……

Good bye…..

http://www.csd.uwo.ca/~pettypi/elevon/baugher_us/f022.html

The two-dimensional engine nozzles of the YF-22A can be vectored 20 degrees up or down at any power setting. Vectored thrust is most effective at high engine power and is most useful at each end of the speed range. Continuous vectored thrust can also be used for high-speed turns (e. g. 6 g at Mach 1.8 is an ATF objective), where horizontal tail authority might not be sufficient. Vectored thrust also improves roll control. An afterburner is incorporated for use in combat or for Mach 2 plus dash speeds.

The first thrust-vectoring by the YF-22A was performed by N22YF on November 15, with test pilot Dave Ferguson exploring the roll response enhancement that this feature could afford. With 2-dimensional thrust vectoring, the aircraft could achieve supersonic roll and pitch rates in excess of those that can be achieved by a conventional fighter at subsonic speeds. At speeds above Mach 1.4, the two-dimensional nozzles improved turning rates by about 35 percent. The YF-22A was able to perform maneuvers when it was far beyond the stall angle of attack and could perform bank-to-bank rolls at speeds as low as 80 knots and angles of attack as high as 60 degrees. Enhanced agility at high angles of attack will give the F-22A an important edge over other fighters, allowing weapons lock-on with a conventional aircraft that is unable to avoid flick-pointing. The nozzles give a four-fold improvement in pitch-down nose recovery, allowing the aircraft to resume normal flight attitudes within a second.

http://www.globalsecurity.org/military/systems/aircraft/f-22-f119.htm

The two-dimensional nozzle vectors thrust 20 degrees up and down for improved aircraft agility. This vectoring increases the roll rate of the aircraft by 50 percent and has features that contribute to the aircraft stealth requirements.

Do a little research to back up your retort please.

An F-15 for instance once it gets into a fairly high angle of attack cannot roll effectly as its tail is hard pressed to keep the aircraft in the turn. By sharing work between tailplane and vectoring nozzles the Raptor is able to maintain alpha while permitting roll as well, up to its design alpha of 60 degrees.

Here’s a shot of the F135 FSD engine at Arnold Engineering, it has a non vectoring low observable nozzle, from what i’ve seen from both P&W and GE they’ll look broadly similar. The second shot is the GE LO axi nozzle on an F110.

I remember hearing they wanted to develop a spherical convergent flap nozzle for the Raptor, they tested it in an advanced demonstrator engine using YF-22 nozzle parts modified. An axisymmetric vectoring nozzle would be a good idea, its lower in weight, has a quicker vectoring response and is more efficient than a 2D nozzle, the transition duct that goes from round to rectangular, there’s always going to be scrub on exit because of exhaust swirl. Not to mention the old bogey of pressure wanting to make round the rectangular portions of the nozzle. It’s just plain better physics to go for an axisymmetric nozzle.

One recent problem the Raptor has had is excessive heating of the exhaust section center fairing, that part that sticks out of the back of the aircraft between the 2D nozzles. They’re thinking they’re either going to have to put line the thing with copper sheet on the inside to help dissipate the heat or use something else.