ATAR 9K50 - developments?

Hello forum members!

The ATAR 9K50 was an axial flow turbojet that was developed in the 1960's. It has powered the Mirage IV bomber, certain versions of the Mirage III family, and the Mirage F1.

Was any further development contemplated by SNECMA?

I do know that Atlas Aviation/Denel in South Africa did do some modifications. One such mod was a welded combustion chamber instead of the old riveted model, which showed some improvements, mostly maintenance related I believe.

Interestingly, due to Apartheid, this engine was to power the Carver project, at least initially, due to the arms embargo. Obviously, they had other irons in the fire for future motors though, as events proved subsequently.
One of the Carver Project leaders stated that improvements were to be made to this engine, leading to at least a 10% increase in performance, at least initially. Some info exists that Atals/Denel did some single crystal casting work, aimed at the blades obviously. Later, there was mention of an ATAR plus, with South African and Spanish involvement that looked at a new combustion chamber, new turbine, and new engine control electronics.

South Africa did hold a licence to produce the 9K50, but to public knowledge, produced "hot parts" only, and not complete units such as engine casings, although they were obviously capable of doing thus.

Was there any further SNECMA ATAR 9K50 developments? Seeing as the engine is modular, what sort of improvements were likely achievable by South Africa in the late 1980's/early 1990's, considering the 20 year old technology (at least) in the basic motor, and it's modest PR ratio? Certainly a new compressor or turbine, with modern metallurgy would be aimed at increased thrust ... does any one know what would be achievable on this engine?

So, any fellow forumites with any knowledge, or even informed opinion on the questions above?

Hey didn't saw this thread ten years ago.

I've never heard any Atar development past the 9K50 mark. considering earlier (and very weird !) SNECMA - Atar numbering system, should have been something like "9K51" or "9K60".

If an improved 9K50 had ever existed, the Mirage 50 (1979) or III-NG (1982) and all the south American updates (Pantera, Finger, whatever) would have it at some point.
Also the Mirage G4 / G8, the later which hit Mach 2.34 with a pair of 9K50s in 1973.

I think the Atar was definitively at the end of its development rope by 1968 for two reasons.

First, it derived from the - already 25 years old by then ! - BMW-003 of He-162 fame. That one was barely 900 kg of thrust. The first ATAR ever, in 1948, already doubled that to 1700 kg. successive iterations brought thrust to 7200 kgp of the 9K50 - in 1968: 20 years after the Atar 101V and 25 years after the BMW 003 !

Secondly, SNECMA put all their resources in the M53 - right from 1968, too.

Note that the M53 was explicitely designed to fit into an Atar engine bay so that swaps could happen. Hint: the Deal of the Century Mirage F1 exactly did that.
-I think operational Mirage G8s were to have M53s instead of the prototypes Atar 9K50.
-The ACF / G8A which borrowed a lot from the G8 (as the name entail, minus the VG) certainly got M53s.

Holy thread necro, Batman!
Thanks for the response Archie.
I know that the 9k50 was antiquated, and that the M53 was the engine from the 70's to get the funding.
It was just an interest in seeing what could be done realistically with it.
I think the work done toward new blade materials/turbine, new compressor, and new electronics was an interim step....to get an increased thrust version, but more importantly, as a step toward technology/industrial and skills development toward a new engine and the industrial and knowledge skills that would require.

There WAS in fact a minor Snecma development of the 9K-50 for the upgraded Mirage F-1 by Astrac... called the « ATAR Gratification ».

Though there have been proposals to re-engine the Mirage F1 (with South Africa successfully integrating a derivative of the MiG-29’s RD-33 engine) the MF2000 retains the basic Snecma ATAR 9K50 engine, though this is ‘optimised’ under the so-called ATAR Gratification programme, with a new compressor module, a redesigned HP turbine, a six per cent increase in mass flow and a 40 per cent increase in turbine entry temperatures combining to increase thrust from 7,200 kg to 7,500 kg.

There's a limit on what you can achieve caused by the basic design of the engine. 9 compressor stages on a single spool giving a bit over a 6:1 pressure ratio isn't going to break any records. You can make it run hotter by better turbine cooling and materials, maybe spin the compressor a bit faster. For a single shaft turbojet the only way forward is adding more stages, which impacts weight and length, or adding variable stators, which is rather a tricky retrofit.

Modern jet engine compressor designs can give more than 1.5x pressure rise per stage compared to 1.2x for the ATAR 9K50. If it were possible to retrofit these into an ATAR, you could theoretically get a pressure ratio almost doubled with only 6 stages versus 9 - but then you'd double the mass flow requirements, and you have essentially a new engine.

kaiserbill said:

Hello forum members!

The ATAR 9K50 was an axial flow turbojet that was developed in the 1960's. It has powered the Mirage IV bomber, certain versions of the Mirage III family, and the Mirage F1.

Was any further development contemplated by SNECMA?

Click to expand...

There was a Super ATAR in 1960 with variable stators like the J-79. Basically a new engine though.

SNECMA did their best to try and break their ATAR "monoculture". In the early 50's were the Olympus and Vulcain which went nowhere. Also the late 50's Super-Atar, another dead end.
They probably knew right from the beginning the Atar limits as explained by Overscan above.
By 1959 they were forced to try and take a J75 licence from Pratt and more generally, to pass some of their stock in exchange (around 13%, from memory). J75 went nowhere but the TF104 / TF30 series greatly helped M53 development.

H_K said:

There WAS in fact a minor Snecma development of the 9K-50 for the upgraded Mirage F-1 by Astrac... called the « ATAR Gratification ».

Though there have been proposals to re-engine the Mirage F1 (with South Africa successfully integrating a derivative of the MiG-29’s RD-33 engine) the MF2000 retains the basic Snecma ATAR 9K50 engine, though this is ‘optimised’ under the so-called ATAR Gratification programme, with a new compressor module, a redesigned HP turbine, a six per cent increase in mass flow and a 40 per cent increase in turbine entry temperatures combining to increase thrust from 7,200 kg to 7,500 kg.

Mirage upgrade augments new fighter force | Times Aerospace

Upgraded F-5s have already entered service and Morocco ’s MF2000 Mirage F1 upgrade is now flying in prototype form. The Moroccan Mirage F1 upgrade was designed and is being integrated by the new Association Sagem Thales pour la Rénovation d'Avions de Combat (ASTRAC) consortium. This is a joint...

www.arabianaerospace.aero

Click to expand...

Thanks for that !

+300 kg : appreciable for sure, but nothing like the Atar 101 > Atar 9 leap (4500 to 6000, +1500) or even the varied iterations from 9C to 9K50 (+1200). And that, with 1980 / 90 tech level... clearly the development potential was gone.

Archibald said:

H_K said:

There WAS in fact a minor Snecma development of the 9K-50 for the upgraded Mirage F-1 by Astrac... called the « ATAR Gratification ».

Though there have been proposals to re-engine the Mirage F1 (with South Africa successfully integrating a derivative of the MiG-29’s RD-33 engine) the MF2000 retains the basic Snecma ATAR 9K50 engine, though this is ‘optimised’ under the so-called ATAR Gratification programme, with a new compressor module, a redesigned HP turbine, a six per cent increase in mass flow and a 40 per cent increase in turbine entry temperatures combining to increase thrust from 7,200 kg to 7,500 kg.

Mirage upgrade augments new fighter force | Times Aerospace

Upgraded F-5s have already entered service and Morocco ’s MF2000 Mirage F1 upgrade is now flying in prototype form. The Moroccan Mirage F1 upgrade was designed and is being integrated by the new Association Sagem Thales pour la Rénovation d'Avions de Combat (ASTRAC) consortium. This is a joint...

www.arabianaerospace.aero

Click to expand...

Thanks for that !

+300 kg : appreciable for sure, but nothing like the Atar 101 > Atar 9 leap (4500 to 6000, +1500) or even the varied iterations from 9C to 9K50 (+1200). And that, with 1980 / 90 tech level... clearly the development potential was gone.

Click to expand...

Wasn't M53 derived from Atar? Also there detailed information on last few models of Atar? Such as if its rotor is single spool as too material of it along material used for compressor blades, etc... As for development potential of Atar.

It may not have had then due to limitations of aerospace science and technology when for example in present day there would be ways to improve it and remember that South Africa did modifications of it after French stopped development of Atar.

You could improve OPR and TET by replacing compressors with for example titanium alloy bladed disks(blisk) to increase thrust.

But then question is how it would impact lifespan as it deviates from specification of other components.

No, the M53 was an entirely new design.

H_K said:

There WAS in fact a minor Snecma development of the 9K-50 for the upgraded Mirage F-1 by Astrac... called the « ATAR Gratification ».

Though there have been proposals to re-engine the Mirage F1 (with South Africa successfully integrating a derivative of the MiG-29’s RD-33 engine) the MF2000 retains the basic Snecma ATAR 9K50 engine, though this is ‘optimised’ under the so-called ATAR Gratification programme, with a new compressor module, a redesigned HP turbine, a six per cent increase in mass flow and a 40 per cent increase in turbine entry temperatures combining to increase thrust from 7,200 kg to 7,500 kg.

Mirage upgrade augments new fighter force | Times Aerospace

Upgraded F-5s have already entered service and Morocco ’s MF2000 Mirage F1 upgrade is now flying in prototype form. The Moroccan Mirage F1 upgrade was designed and is being integrated by the new Association Sagem Thales pour la Rénovation d'Avions de Combat (ASTRAC) consortium. This is a joint...

www.arabianaerospace.aero

Click to expand...

As H.K said here - while SNECMA stopped at the 9K50 mark circa 1968, 15 years later and per lack of a better engine the South Africans tried one more upgrade... and with 1985 level of technology only got +300 kg of thrust, so in the 7500 kg ballpark.
For the sake of comparison
M53-2, 1972: 8200 kg thrust
M53-5, 1980: 8500 kg thrust
M53-P2, 1984: 9700 kg thrust (for the Mirage 2000N / D: two-seat strike aircraft, so heaviers with heavy payload: they badly MOAR thrust and the P2 was the answer)

Then why was M53 originally named during development as Super Atar?

It is disingenuous to use South Africa as some sort of argument involving Atar 9K50 as that was under apartheid regime that was under heavy embargo thus access to modern technologies was limited to non-existent with exception of some covert assistance from fellow apartheid ally Israel hence Atlas and its production of Cheetah among other things.

Also around same time 9K50 was designed and tested there was from General Electric J85-GE-21 that while much smaller and lighter it was of comparable complexity of 9 axial compressors with 2 turbines on single shaft yet much higher overall pressure ratio of 8.1 to 1 compared to 6.15 to 1 of 9K50 along turbine inlet temperature of 980 celsius compared to 9K50 having 935 celsius.

9 series had any titanium and that was used for rear section(afterburner?) while J85-GE-21 used titanium for rotor and compressor blades.

ATAR Gratification program improvements likely used same type of metals for compressors and turbines with difference being different geometry of blades to improve mass flow, maybe blades a bit lighter, but overall very conservative renovation than proper upgrade.

Also performance of afterburner relies on design of afterburner, 9K50 increase in thrust between dry and wet is comparable to J85-GE-21 with 44% increase while for example AL-21 with its much shorter afterburner section has 53% increase.

If rotor and compressor blades were of titanium and there was better afterburner design implemented that output of Atar could have potentially reached afterburner output of M53-2 with comparable specific fuel consumption.

But at the end of the day M53-2 would be much cheaper than if Atar was improved with extensive use of parts made of titanium.

M53-P2 used titanium for compressor blades which among other things contributed to increase in performance.

View: https://www.youtube.com/watch?v=zCAR4wPrwrg

How turbofan jet engines were made in the ’80s | Safran​

Archibald said:

As H.K said here - while SNECMA stopped at the 9K50 mark circa 1968, 15 years later and per lack of a better engine the South Africans tried one more upgrade... and with 1985 level of technology only got +300 kg of thrust, so in the 7500 kg ballpark.

Click to expand...

The Project Officer of the Carver stated that there was a thrust increase component and weight reduction component to South Africa's ATAR programme.
An thrust increase of about 10% was apparently met, but the weight reduction aims were "less successful".
This should mean a thrust bracket of around 5500kg dry, and around 8000kg afterburning.
No idea what the weight reduction goal was, or what was achieved.

There comes a point where a clean sheet design becomes easier or better, and I suspect this would have been the case with Carver if a suitable foreign engine was not procured. In fact, this is the exact route all South African projects followed.

kaiserbill said:

Archibald said:

As H.K said here - while SNECMA stopped at the 9K50 mark circa 1968, 15 years later and per lack of a better engine the South Africans tried one more upgrade... and with 1985 level of technology only got +300 kg of thrust, so in the 7500 kg ballpark.

Click to expand...

The Project Officer of the Carver stated that there was a thrust increase component and weight reduction component to South Africa's ATAR programme.
An approximate 10% thrust increase was met, but the weight reduction aims were "less successful".
This should mean a thrust bracket of around 5500kg dry, and around 8000kg afterburning.
No idea what the weight reduction goal was, or what was achieved.

Click to expand...

Well in my opinion safe bet is compressor blades being made out of titanium as one of achievements.

BullpupRafale said:

Well in my opinion safe bet is compressor blades being made out of titanium as one of achievements.

Click to expand...

The details of the programme have been outlined on the forum before...and involved a host of measures. From memory, there was a welded instead of rivetted combustion chamber, new turbine, engine electronics, and single crystal blades.
So the metallurgy in the blades was definitely modernised, but no idea about the shape.
It's interesting to note South Africa did exhibit a small engine at an expo (not the basic ap1 Project Apartment jet engine) that had definite curved shaping on the blades, but more information on that engine has been negligible unfortunately, like many of the projects.

kaiserbill said:

The details of the programme have been outlined on the forum before...and involved a host of measures. From memory, there was a welded instead of rivetted combustion chamber, engine electronics, and single crystal blades.

Click to expand...

I doubt there would be 10% increase if single crystal blades were of same material as previous blades.

At least with titanium blades one could expect such increase to reasonable with that since those would be nearly half the weight.

Along if something like bladed disk concept was used.

We don't know the details of the alloys/metallurgy used in either the compressor blades, nor turbine blades unfortunately.
They mentioned "new turbine" whatever that meant.

"Disingenous " really ?
Be careful about the words you use...

I used South Africa because it was the one and only post 9K50 ever done. Even SNECMA had given up.

And try being less OBTUSE in your reasoning, damn it.

"Super Atar" was only a vague designation for marketing purposes. Also M53-2 and 9K50 both started in 1968 were designed to be somewhat interchangeable in the Mirage F1 and G8 engine bays.

Professor Glen Snedden, previously of the CSIR, worked on a collaborative venture with SNECMA on the ATAR+NGV when he was at the CSIR, and has many academic papers published on various gas turbine design research matters, including blades.


But he joined the CSIR in the mid 90's, so I don't think he would have been involved in the original ATAR improvement programme.
Edit: His resume does include work with Klimov, which I take to mean the Cheetah and Mirage F1 re-engining project, so he might have worked with another aerospace firm (such as Atlas or Aerotek) before the CSIR proper. Certainly he was more in the field of military engines.