Visible thermocouples?

Design and construction
  • Author
  • Message
Offline

vitormoura

Newbie

Newbie

  • Posts: 2
  • Joined: 02 Nov 2017, 18:42

Unread post11 Feb 2018, 01:31

Hello all,

I happen to be in a group about aviation with friends and someone shared this image, which is awesome by the way.

But I'm wondering, are there any visible thermocouples in this image?

Image
Offline
User avatar

neptune

Elite 2K

Elite 2K

  • Posts: 2885
  • Joined: 24 Oct 2008, 00:03
  • Location: Houston

Unread post11 Feb 2018, 10:25

vitormoura wrote:Hello all,

I happen to be in a group about aviation with friends and someone shared this image, which is awesome by the way.

But I'm wondering, are there any visible thermocouples in this image?

Image


....just a guess!, upper left center of photo, red wire with blue clamps appears to be added for temporary high Temperature monitoring.
...did not know the exhaust duct could swivel under the fuselage to that extent (would allow for reverse thrust position, flying backwards)!
... Excellent photo of the "turkey feathers"!
:)
Offline
User avatar

spazsinbad

Elite 3K

Elite 3K

  • Posts: 21727
  • Joined: 05 May 2009, 21:31
  • Location: ɐıןɐɹʇsn∀¯\_(ツ)_/¯
  • Warnings: -1

Unread post11 Feb 2018, 10:32

:devil: How swivelly is my duck tail? 95 degrees in 2.5 seconds from horizontal - enabling able to fly backwards at 30 KIAS.
There is some YAW control also, when waggling the duck tail swivel duct - how much? +/- 13 degree yaw angle.
http://4.bp.blogspot.com/-ABF2yIXwytY/U ... eTimes.jpg

"...The 3BSD provides yaw control through the first swivel bearing. The resulting yaw thrust force is applied through the centerline of the engine – very near the overall aircraft vertical center of gravity. In this position, the thrust force results in no added rolling moment.... http://www.codeonemagazine.com/article.html?item_id=137
RAN FAA A4G Skyhawk 1970s: https://www.faaaa.asn.au/spazsinbad-a4g/ AND https://www.youtube.com/channel/UCwqC_s6gcCVvG7NOge3qfAQ/
Offline
User avatar

steve2267

Elite 1K

Elite 1K

  • Posts: 1768
  • Joined: 12 Jun 2016, 17:36

Unread post13 Feb 2018, 05:14

I've always marvelled that all photographs that I have seen to date of the inside of the F135 nozzle showed a white surface. And not just a white surface that was gradually being dulled... but a really WHITE surface. I have not seen it discussed before. Unless maintenance continually re-paints the inside of the nozzle, I'm fairly certain it cannot be a paint. I presumed it was some sort of ceramic material used for purposes of decreasing the thermal signature of the F135.

But here in this photograph I see the first evidence of the gradual wear and tear on this "white" surface. If the colors of this photograph are accurate, then it is not as WHITE as I thought originally. Still, the photo could be off a bit, color-wise.
Take an F-16, stir in A-7, add dollop of F-117 & gob of F-22, sprinkle with AV-8B, stir well, then bake. Whaddya get? An F-35.
Offline

hornetfinn

Elite 2K

Elite 2K

  • Posts: 2540
  • Joined: 13 Mar 2013, 08:31
  • Location: Finland

Unread post13 Feb 2018, 10:23

steve2267 wrote:I've always marvelled that all photographs that I have seen to date of the inside of the F135 nozzle showed a white surface. And not just a white surface that was gradually being dulled... but a really WHITE surface. I have not seen it discussed before. Unless maintenance continually re-paints the inside of the nozzle, I'm fairly certain it cannot be a paint. I presumed it was some sort of ceramic material used for purposes of decreasing the thermal signature of the F135.

But here in this photograph I see the first evidence of the gradual wear and tear on this "white" surface. If the colors of this photograph are accurate, then it is not as WHITE as I thought originally. Still, the photo could be off a bit, color-wise.


That's Thermal Barrier Coating (TBC) which is usually white (or whiteish) in color due to white color having lowest thermal absorpivity. It protects the nozzles and also lowers their thermal signature as they keep cooler. It's used in very many applications nowadays, including inside jet engine hot parts and other high temperature applications.

F-22 nozzles also seem to have similar coating and Sukhois with TVC seem to have some kind of whiteish coating also.
Offline
User avatar

steve2267

Elite 1K

Elite 1K

  • Posts: 1768
  • Joined: 12 Jun 2016, 17:36

Unread post13 Feb 2018, 18:39

hornetfinn wrote:
F-22 nozzles also seem to have similar coating and Sukhois with TVC seem to have some kind of whiteish coating also.


Thanks hf. I'll keep my eyes open for it the next time I see photos of F-22 / Sukhois nozzles. I had only noticed it on F-35s.
Take an F-16, stir in A-7, add dollop of F-117 & gob of F-22, sprinkle with AV-8B, stir well, then bake. Whaddya get? An F-35.

Return to F-35 Design & Construction

Who is online

Users browsing this forum: No registered users and 3 guests