TR TF-X KAAN Fighter Jet

[IC3M@N FX]

Neither the F110 nor the F119 is an absolutely high-end engine right now. Turkiye can develop and produce an engine better than F110.

OK, you don't seem to understand Turkey doesn't have the financial means, you can't just develop an absolutely high end engine and produce it on an assembly line just because you or I want it that way. The aircraft also has to be affordable, both in terms of the purchase price for the armed forces and the sales price for export.
If it's more expensive than an F-35/J-35, you've already lost the export market.
The more complex the engine is, the more expensive it is to manufacture and maintain.
Turkey does not have a yearly military budget of 800-900 billion dollars like the US, which develops weapon systems/engines without compromise if it has to.
Therefore, Turkey must first develop an engine that surpasses the upper performance class, in this case the F-110/EJ200.
The dimensions of the F-110 in TAI KAAN are the fixed benchmark, so you can't just change the engine at will, but there are limits set by the size of the F-110.
The F-110 engine has 3 main fans and 9 compressors as well as a low pressure turbine and a high pressure turbine.
One could reduce one of the main fans and one compressor and use 2 low- and high-pressure turbines instead.
The result is an engine with significantly fewer mechanically moving parts. The complexity of the engine is lower, as is the manufacturing and maintenance, and it is still slightly more powerful than an F-110/EJ200. You can still incorporate modern approaches like VCT & Co.
If you then have variable air intakes in the TAI KAAN, you can also trigger a RAM effect and get additional thrust, on average up to 10% more thrust is possible, e.g. for supercruise without afterburner or better thrust in the subsonic range.

 

[Turkic]

Turkey doesn't have the financial means, you can't just develop an absolutely high end engine and produce it on an assembly line just because you or I want it that way.

Actually the needed amount of money do not drastically increase if you're not developing an F-135. It's roughly 3 to 6 billion dollars at countries with high engineering costs. I'm not pointing the number but the fact that it's not much different to develop a 30k lb engine than a 36k lb engine in terms of costs. Spending half a billion more to develop a high-end engine sounds logicful since they're among the most important defence industry products. Also every million you invest in turbofan engines provides you a good increase in performance (if you'll be able to improve it more by spending more). To me, they're price/performance products of defence industry at development stage.

All these I say are outcomes of my basic researches and my thoughts. I'm not a master on this topic. So I might be wrong.

 

[Huelague]

We have an additional military budget of $20 billion for such projects.

 

[Yasar_TR]

Turkey doesn't have the financial means, you can't just develop an absolutely high end engine and produce it on an assembly line

No one is saying that an absolutely high end engine is to be produced. What KAAN will have is an engine that is similar to an F-119. Probably with few more extras like CMC parts in certain hot sections.

If it's more expensive than an F-35/J-35, you've already lost the export market.

Not really. There are loads of countries that can’t have access to F35. Also we know the performance of Chinese tech. In UCAV scene many countries are switching from Chinese to Turkish. Plus all the countries that already use and are partners with Turkiye, will want to carry on, as weapons business is also a based on partnership.

Turkey must first develop an engine that surpasses the upper performance class, in this case the F-110/EJ200.

No! Türkiye will produce an engine that is commensurate with KAAN and its intended performance. It has to have 22000-26000lbf dry thrust and 34000-38000lbf wet thrust. Anything less means the fighter is compromised.

The dimensions of the F-110 in TAI KAAN are the fixed benchmark, so you can't just change the engine at will, but there are limits set by the size of the F-110.
The F-110 engine has 3 main fans and 9 compressors as well as a low pressure turbine and a high pressure turbine.

Not really. As long as the engine compartment of KAAN can house the engine, any size will do.
The number of stages of turbines are there for a reason. But not for what you are mentioning. Generally with a larger fan stage, to be able to drive this large fan more efficiently, a second LP turbine stage is introduced. Because the LP turbine drives the LP fans. But for an engine like KAAN’s, where you don’t have a large fan, it is not necessary to have a second LP turbine stage.
HP Turbine stage drives the HP compressor stages. In most engines a single stage of HP turbine is efficient enough to meet the demands.
These are calculated according to the diameter of the particular stages and the flow speed of the air being forced through them.

The result is an engine with significantly fewer mechanically moving parts. The complexity of the engine is lower, as is the manufacturing and maintenance, and it is still slightly more powerful than an F-110/EJ200

The engine we are trying to manufacture is more complex and intricate than a F110 or EJ200. (Besides EJ200 has too low a thrust for KAAN. It is not correct to even mention it. )
KAAN’s engine has to be complex and intricate. Because this engine has to be stealthy and with very low IR signature.

If you then have variable air intakes in the TAI KAAN

Variable air intakes, used as in f14 and f15 are there to regulate air flow in to the fan section, keeping the speed of flow at subsonic levels. Not for augmenting thrust.
This technology is used in Typhoon too. This is to improve the performance of the plane at high angle of attack at transonic speeds..