MIG-29 Question?
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How come the GAF never incorporated the smokeless mod for their J79s full time? I understand they had it as a 'war only' option, did the smokeless mod increase wear and tear on the engines due to the higher combustion temperatures that much that it was not worth it during peacetime?
As an aside, look at almost any footage of current JASDF F-4's and you'd think they didn't have J79s, they're as clean a whistle!
-RP
As an aside, look at almost any footage of current JASDF F-4's and you'd think they didn't have J79s, they're as clean a whistle!
-RP
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For those in the know, was the smoke the first thing you usually spotted when practising air to air? I guess when conducting NATO patrols or any other operations the Mig 29s were a bit easier to spot, or am I wrong?
Thanks F26
Thanks F26
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A couple of things regarding combustors on F-4 Phantoms (J79 engines) and Mig-29 (RD-33 engines):
The J79 engine used a 10 cannular combustor system.
The RD-33 used an annular combustor system.
The early GE J79 engines used a longer combustor "can" and dual orifice pressure atomizing fuel nozzles, the nozzles had a single fuel inlet and an external fuel flow dividing valve. Starting with the GE J79-17C engine, the fuel nozzle tip was changed to provide air blast atomization to improve fuel/air mixing. The new fuel nozzle was made longer to compensate for a shorter "can" length that was also developed. The new fuel nozzle was quite complex as it involved the addition of eight radial low pressure secondary fuel distributers. This change was known as "Low Smoke - Long Life Combustor" and it was an improvement for sure.
I was with a team of engineers that visited all the important Soviet jet engine plants just as the Soviet Union was dissolving. We were looking for advanced Russian technology knowhow, something better than what we were doing at the time. I had an opportunity during this visit to see a RD33 engine with all the parts laid out on tables for our review. The engine was a basic copy of an F404 engine including the HP turbine blade cooling methodology. However, there was a significant difference and that was the manufacturing ability to produce the wanted component designs. This is where the early "smokey" RD33 engines came up short. There wasn't the manufacturing capability to produce the sophisticated type of parts (fuel nozzles) that was developed and being used in the Western world. We could see that throughout the RD33 engine, they had the right engineering but not the manufacturing capability. So the Chief Designer is covering for the manufacturing shortcomings.
The J79 engine used a 10 cannular combustor system.
The RD-33 used an annular combustor system.
The early GE J79 engines used a longer combustor "can" and dual orifice pressure atomizing fuel nozzles, the nozzles had a single fuel inlet and an external fuel flow dividing valve. Starting with the GE J79-17C engine, the fuel nozzle tip was changed to provide air blast atomization to improve fuel/air mixing. The new fuel nozzle was made longer to compensate for a shorter "can" length that was also developed. The new fuel nozzle was quite complex as it involved the addition of eight radial low pressure secondary fuel distributers. This change was known as "Low Smoke - Long Life Combustor" and it was an improvement for sure.
I was with a team of engineers that visited all the important Soviet jet engine plants just as the Soviet Union was dissolving. We were looking for advanced Russian technology knowhow, something better than what we were doing at the time. I had an opportunity during this visit to see a RD33 engine with all the parts laid out on tables for our review. The engine was a basic copy of an F404 engine including the HP turbine blade cooling methodology. However, there was a significant difference and that was the manufacturing ability to produce the wanted component designs. This is where the early "smokey" RD33 engines came up short. There wasn't the manufacturing capability to produce the sophisticated type of parts (fuel nozzles) that was developed and being used in the Western world. We could see that throughout the RD33 engine, they had the right engineering but not the manufacturing capability. So the Chief Designer is covering for the manufacturing shortcomings.
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^^^Oops, sorry. Huge photo. I'll leave it for a bit and then take it down if it's annoying.
The early GE J79 engines used a longer combustor "can" and dual orifice pressure atomizing fuel nozzles, the nozzles had a single fuel inlet and an external fuel flow dividing valve. Starting with the GE J79-17C engine, the fuel nozzle tip was changed to provide air blast atomization to improve fuel/air mixing. The new fuel nozzle was made longer to compensate for a shorter "can" length that was also developed. The new fuel nozzle was quite complex as it involved the addition of eight radial low pressure secondary fuel distributers. This change was known as "Low Smoke - Long Life Combustor" and it was an improvement for sure.
I was able to find a pdf about it, are there any pics or cutaways somewhere?
The ones on the report are pretty much useless (at least for me). Here's the file:
www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA095057
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No, they already had GE engines. You're probably thinking of the Israeli 'Super Phantom' proposal. One aircraft flew with a pair of P&W PW1120s, which were developed from the P&W F100. Although test flights showed significant improvements in performance, in the end, the upgrade (which became the 'Kurnass 2000') was limited to avionics and structural upgrades and the PW1120 died along with the cancellation of the IAI Lavi project.
Interestingly, BMAC, also working with P&W PW1120s, did some development work on a 'Super Phantom' for the USAF, one of the 'novel' features was a palletized conformal belly fuel tank with hard points and integrated chaff/flare dispensers!
-RP
Interestingly, BMAC, also working with P&W PW1120s, did some development work on a 'Super Phantom' for the USAF, one of the 'novel' features was a palletized conformal belly fuel tank with hard points and integrated chaff/flare dispensers!
-RP
MiG-29 Fulcrum Smoke
Sorry, bit late in coming into this discussion. Back in the mid-80s I spent many happy hours watching early-model Fulcrums, both Soviet AF and East German, and have no memory at all of smoke being particularly noticeable. Fitters, on the other hand, I do remember producing clouds of the black stuff. Could just be age and decrepitude catching up with me, or that smoke was so normal that we just failed to register it!
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DirtyProp,
I couldn't find anything much better than the hand sketches/drawing you referenced, but there are a couple of videos that might be helpful to you:
https://www.youtube.com/watch?v=Or6mIaSWZ8g
https://www.youtube.com/watch?v=QPK_eiNng7Q
I couldn't find anything much better than the hand sketches/drawing you referenced, but there are a couple of videos that might be helpful to you:
https://www.youtube.com/watch?v=Or6mIaSWZ8g
https://www.youtube.com/watch?v=QPK_eiNng7Q
