Forum: F-16 Design & Construction

OK...I am building a 1/10 scale turbine F-15...and I want to make an operational C-D nozzle dose anybody have some good pictures or a breakdown of how the nozzle works and how the pedels accuate? thanks

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I think you need to do some more research. The 15's at Langley did not have any back in 87-90, and the F-15C/D/E's at Lakenheath did not have any turkey feather either. I have seen them on model and toy airplanes but not on any actual birds.

I asked my old man about these, he said they were yanked in the late 70's and early 80's. They did not provide any performance improvement.

TEG may have more information for you.

they removed the "turkey feather" nozzel covers in the early '80's due to them getting ripped off at the area between the engines at high speed, but I was talking about the accual nozzel, with the linkage and such that the turkey feathers cover up

External "turkey feathers" or not, all PW F100's, with the exception of the -220U, are convergent-divergent nozzles. The C-D term describes the internal variable geometerty of the nozzle, not the external flaps. There are convergent flaps and divergent flaps inside the nozzle, that when actuated, increase and decreade Aj, or nozzle area. Some aerodynamic forces peculiar to the F15 airframe seemed to over-stress the external flaps and cause them to fail, but the absence of them did not adversely effect the performance of the engine or airframe so most, but not all, F15 operators removed them, USAF included. This has not proven to be a significant issue on the F16 aircraft.

lewandom wrote:

I want to make an operational C-D nozzle dose anybody have some good pictures or a breakdown of how the nozzle works and how the pedels accuate? thanks

You realize that the F100's nozzle includes

A drive motor (Convergent Exhaust Nozzle Control -AKA CENC)
5 mechanical 'screw-jack' actuators (1 Primary and 4 Secondary)
7 flexible-drive shafts (2 primary and 5 secondary)
1 Synchronizing ring that keeps everything working together with 5 links that connect to the actuators
75 linkages that push/pull the segments open closed; long/short, lever arms, etc
15 balance segments
15 balance seals
15 convergent segments with 15 liners attached
15 convergent seals with 15 liners attached
15 divergent segments
15 divergent seals

Now I think that sums up the 'moving' parts. There are also;

15 balance segment links
50 brackets to support things in/on the nozzle
1 nozzle support that all these parts go into/on to compose the 'nozzle assembly'
30 bridge clamps

I'll see what else I can dig up.

Keep 'em flyin' Thumb

TEG

I appreaceate it, I was going to use bleed air through the starter gas port on each engine working on a set of gas pistons with springs so the springs hold the assembly open and the gas pistons push it closed with the increase in gas pressure as the engine spools up, hopefully I can simplify it so it's funtional and looks like the c-d nozzle and is still relitevly lightweight

Will your small turbine engine have the OPR to deal with the restricted Aj?

TEG

Examples of nozzle movements.

http://www.youtube.com/watch?v=tfNeAr8ix10 (01:28 on the video for the Nozzle Check)

http://www.youtube.com/watch?v=5F-I08xLWqM (00:19 nozzle swings closed)

It's possible and this is how it should look to have a real workable nozzle.

Not trying to step on any toes or anything Embarassed

wow is that a pic of an F-15 (an E model based on the way the AIM-120's are hanging off of it and the pod up front) W/ GE engines....never knew they made any W/ GE's...
The nozzel on the K-80F's I plan on using are around 3" in diameter, and the engine tube between the engine and the rear if the jet is 4.75" in diameter so i don't think it necking down will make too much of a diffrance...I have another crazy Idea in my head....just an Idea...not nesseserely going to use it...but mabe an afterburner, there's prob. a good 6-8 inches between the end of the engines and the nozzle, plenty of room for one, I know it's aganst AMA rules, so I'll have to disable it at AMA fields, but if I ever get back to the southwest it would tear up a dry lakebed or two, I appcerate all the help, dose anyone have any tech drawings, IPB's, TO's ect. that illistrate how it all fits togeather?, only post it if its not controled doc. though. Thanks

lewandom wrote:

wow is that a pic of an F-15 (an E model based on the way the AIM-120's are hanging off of it and the pod up front) W/ GE engines....never knew they made any W/ GE's...
The nozzel on the K-80F's I plan on using are around 3" in diameter, and the engine tube between the engine and the rear if the jet is 4.75" in diameter so i don't think it necking down will make too much of a diffrance...I have another crazy Idea in my head....just an Idea...not nesseserely going to use it...but mabe an afterburner, there's prob. a good 6-8 inches between the end of the engines and the nozzle, plenty of room for one, I know it's aganst AMA rules, so I'll have to disable it at AMA fields, but if I ever get back to the southwest it would tear up a dry lakebed or two, I appcerate all the help, dose anyone have any tech drawings, IPB's, TO's ect. that illistrate how it all fits togeather?, only post it if its not controled doc. though. Thanks

There are various F-15E variants with the GE engines, the F-15K for South Korea, the F-15S for Saudi Arabia and the F-15SG for Singapore.

Hi,
Some of you have picture in detail of this particular zone? ring actuator and links? Thanks in advance
Grts,
Pablo

Forum: F-16 Design & Construction

F100-pw C-D nozzle