I thought the Chinese has since righted this engine problem indigenously and is in fact collaborating with Germany on their new engine prototype.
It is, but not at the maximum scale yet. The front cutting edge R&D got the breakthrough, but there is pipeline to implement full scale, and will take time down the road.
Previously, Chinese jet engines last shorter lifespan at turbine blades then Russian / Soviet engines, now longer, slightly more than double. This result is implemented on models like J-11 J-16 I think also J-15. Their next aim is to have monster output power without afterburner, this is WS-15 engine meant for J-20, and to do so, their combustion chamber temperature must be ultra high and the 1st set of turbine blade need to be very high tech materials very precise, and very complicated internal cooling channels. This is also done, now testing the entirely different performance characteristics, and need to change other design parameters to work perfectly with the higher temperature. It will affect whole engine overall, and not only simulations, but constructed prototypes need to be tested on ground test stations, wind tunnels, and mounted on test planes.
This is status of Chinese jet engine progress overall. Many great leaps already made within surprising short time. But it is early still to say that everything they wanted are there already. Far from that. Putin is very worried Xijinping will cancel order of the 24 SU-35 because Chinese had their own progress and very advanced jets. So he rushed to deliver SU-35, cutting production Q ahead of even Russian Air Force's own orders.
PLA wants WS-15 engine to give J-20 MACH 2.0 without afterburner meaning each engine trust 10tons. This is fuel saving mode that can fly thousands of miles at MACH 2. And with afterburner, 15 tons trust to higher speed and accelerations, but this mode is very high consumption of fuel, can not go very far as fuel will be spent too fast.
Putin also got a very strong progress with PRODUCT-30 engine( Изделие 30) for SU-57 which is a great leap too.
PLA, has upgraded several interim models which are make-shift for J-20, before the final version of WS-15 is fully fine tuned. The targeted WS-15 will exceed existing F-22 engines which are models since 1990s.
http://www.sohu.com/a/240955455_99900839
歼20何时配备WS15发动机 中国航空发动机专家透露只需3-5年
2018-07-13 11:51
歼20 /中国 /战斗机
歼20何时配备WS15发动机是大家关注的焦点
歼-20首飞成功之后，何时配备WS-15发动机是大家关注的焦点，近日中国著名发动机专家刘大响同志一锤定音，国产第四代军用小涵道比涡扇发动机研制已经进入尾声，预计3-5年定型，这样意味着歼-20可能在2020年左右配备WS-15发动机。
刘大响同志是中国高推重比发动机预研技术带头人，而高推预研项目主要内容就是高推重比涡扇发动机总体方案研究和顶层设计，也就是说它就是WS-15发动机的前期技术攻关项目，通过这个项目相关单位完成了新一代发动机总体方案和前期设计，进行了高性能风扇、高压压气机、燃烧室、高压涡轮等关键部件攻关和研制，在此基础上进行了高推重比发动机核心机的试制工作，为WS-15发动机立项打下了坚实的基础，从这个角度来讲，刘大响同志所说的四代军用涡扇发动机应该就是WS-15发动机。
一般认为中国WS-15发动机与美国F119相近
还有一个关键词-小涵道比，我们知道涡扇发动机分为内、外两个涵道，前者利用核心机产生高温燃气提供推力，后来利用风扇吹动空气产生推力，从这里我们可以看到涡扇发动机有一部分推力由外涵道产生，这样就提高了推进效率，降低了油耗，涡扇发动机比涡喷发动机省油就是这个原因，外涵道越大，涡扇发动机越省油，所以我们看到民航客机都采用大涵道涡扇发动机就是看中它的经济性，但是外涵道越大，风扇直径越大，阻力也就越大，不利于飞机高速性能，四代机战斗机一个重要性能就是超音速巡航，要求减小飞机直径，这样就需要减少发动机直径，相应涵道比就要降低，美国四代涡扇发动机F119涵道比大约为0.25，而三代F100涡扇发动机涵道比为0.6，不到后者一半，不过涵道比越小也有一个优点，那就是高空高速性能好，高空性能推力下降较小，而超音速巡航多在高空，所以四代军用涡扇发动机涵道比普遍较小。
小涵道比也透露出四代军用涡扇发动机研制难度，一方面要降低涵道比，一方面又要提高推力，降低油耗，这对于发动机总体设计是一个非常大挑战，为此四代军用涡扇发动机选择采用更高涡轮前温度来提高发动机性能，这样又会在发动机材料、工艺等领域带来一系列挑战，另外四代发动机还简化了结构，用更少部件带来更大的空气流量、产生更大的推力，例如三代军用涡扇发动机用9级高压压气机，但是四代军用涡扇发动机降低到6级，美英联合研制的F136涡扇发动机、俄罗斯第四代军用涡扇发动机新产品30还进一步降低到5级高压压气机，发动机部件减少，但是工作需要的空气流量增加了，这样压气机负荷更大，设计、制造难度显然随之增加，四代军用涡扇研制难度之大可见一斑。
歼20还在用俄罗斯发动机，由于性能相对较低，限制了飞机性能完全发挥
歼-20配备WS-15发动机之后，主要性能将会迅速增加，它现在配备的是俄罗斯AL-31FN-M1涡扇发动机，不久还将换装国产WS-10发动机，但是这两种发动机都是三代军用涡扇发动机，推力相对较低，没有推力矢量系统，无法发挥出歼-20完整性能，换装WS-15发动机之后,军用推力（无加力）由8吨提高到10吨，两部发动机就增加4吨，完全可以让歼-20实现超音速巡航，加力推力由13吨提高到15吨以上，战斗机最大推力提高到5吨以上，有效提高了飞机推重比，飞机飞行、机动、起降等性能都得到有效改善。
尤其需要指出的是四代战斗机实现了飞行、推进、火控系统一体化，尤其是推力矢量喷口也被整合进这个系统之中，可以在极端情况下让战斗机仍旧能够保持可以操纵状态，让战斗机具备过失机动能力，这样就能在空战之中占据先机，F22就凭借这个功能展现了一系列让人叹为观止的动作，所以歼-20装备WS-15之后，过失机动能力也将得到有力增强。
F22强大的性能很大程度来源于两部强劲的F119发动机，所以WS-15还要加油
WS-15发动机可靠性也比WS-10和AL-31FN-M1有较大改善，从现在来看，WS-10、AL-31FN-M1首翻小时都在500小时左右，飞行小时数1500小时，而117S这样三代改进型发动机已经达到1000小时首翻，飞行小时4000小时，而F119涡扇发动机的平均维修间隔要比三代涡扇发动机还要高1倍，因此首翻、飞行小时比三代发动机要高，这样歼20配备WS-15之后，保证飞机不需要频繁更换发动机，提高飞机利用率，保证训练飞行时间，增强部队作战能力。
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歼20 When to equip the WS15 engine Chinese aviation engine experts revealed that only 3-5 years
2018-07-13 11:51
歼20
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China
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fighter
歼20 When to equip the WS15 engine is the focus of everyone's attention
After the success of the first flight of the 歼-20, when the WS-15 engine was equipped is the focus of everyone's attention. Recently, the famous Chinese engine expert Liu Daxiang slammed the hammer, and the domestic fourth-generation military small bypass ratio turbofan engine development has come to an end. The five-year finalization means that the 歼-20 may be equipped with a WS-15 engine around 2020.
Comrade Liu Daxiang is the leader of China's high-push-to-weight ratio engine pre-research technology, and the main content of the high-push pre-research project is the overall scheme research and top-level design of the turbo-fan engine, which means that it is the pre-technical project of the WS-15 engine. Through the relevant units of this project, the overall plan and pre-design of the new-generation engine were completed, and key components such as high-performance fans, high-pressure compressors, combustion chambers and high-pressure turbines were developed and developed. Based on this, a high thrust-to-weight ratio engine core was carried out. The trial production of the machine laid a solid foundation for the WS-15 engine project. From this perspective, the four-generation military turbofan engine that Comrade Liu Daxiang said should be the WS-15 engine.
It is generally believed that the Chinese WS-15 engine is similar to the US F119.
There is also a keyword - small bypass ratio, we know that the turbofan engine is divided into two inner and outer ducts. The former uses the core machine to generate high-temperature gas to provide thrust, and then uses the fan to blow the air to generate thrust. From here we can see A part of the thrust of the turbofan engine is generated by the outer duct, which improves the propulsion efficiency and reduces the fuel consumption. This is the reason why the turbofan engine saves fuel compared to the turbojet engine. The larger the outer duct, the more fuel-efficient the turbofan engine is, so we Seeing that the civil aircraft has adopted the large-ducted turbofan engine is to look at its economy, but the larger the outer duct, the larger the fan diameter, the greater the resistance, which is not conducive to the high-speed performance of the aircraft. The fourth-generation fighter is an important The performance is supersonic cruise, which requires reducing the diameter of the aircraft. Therefore, it is necessary to reduce the engine diameter, and the corresponding bypass ratio is reduced. The fourth-generation turbofan engine F119 has a bypass ratio of about 0.25, and the third-generation F100 turbofan engine has a bypass ratio. 0.6, less than half of the latter, but the smaller the bypass ratio, there is also an advantage, that is, the high-altitude high-speed performance is good, and the high-altitude performance thrust is reduced. Small, and supersonic cruises are mostly at high altitude, so the four-generation military turbofan engine is generally smaller than the duct.
Xiaojiedao also revealed the difficulty in the development of four generations of military turbofan engines. On the one hand, it is necessary to reduce the bypass ratio, and on the other hand, it is necessary to increase the thrust and reduce the fuel consumption. This is a very big challenge for the overall design of the engine. Turbofan engines choose to use higher turbine front temperatures to improve engine performance, which in turn poses a series of challenges in engine materials, processes, etc. The other four generations of engines also simplify the structure and bring more air with fewer components. Flow, generate more thrust, such as the three-generation military turbofan engine with 9-stage high-pressure compressor, but the four-generation military turbofan engine is reduced to 6th grade, the United States and Britain jointly developed the F136 turbofan engine, the Russian fourth-generation military turbofan engine The new product 30 is further reduced to a 5-stage high-pressure compressor, and the engine components are reduced, but the air flow required for the work is increased, so that the compressor load is greater, and the design and manufacturing difficulty is obviously increased. The four-generation military turbofan is difficult to develop. It’s a big sight.
歼20 is still using Russian engines, due to the relatively low performance, limiting the full performance of the aircraft
After the 歼-20 is equipped with the WS-15 engine, the main performance will increase rapidly. It is now equipped with the Russian AL-31FN-M1 turbofan engine, and will soon be replaced with the domestic WS-10 engine, but both engines are The three-generation military turbofan engine has relatively low thrust and no thrust vector system. It can not play the full performance of the 歼-20. After the WS-15 engine is replaced, the military thrust (without afterburning) is increased from 8 tons to 10 tons. The engine will increase by 4 tons, which can completely achieve the supersonic cruise of the 歼-20. The afterburning thrust is increased from 13 tons to more than 15 tons, and the maximum thrust of the fighter is increased to more than 5 tons, which effectively improves the aircraft's thrust-to-weight ratio, aircraft flight and maneuver. Performance such as take-off and landing have been effectively improved.
In particular, it is necessary to point out that the four generations of fighters have realized the integration of flight, propulsion and fire control systems. In particular, the thrust vector nozzles have also been integrated into this system, allowing the fighters to remain maneuverable under extreme conditions, allowing the fighters to With the ability to maneuver, so that it can take the lead in air combat, F22 shows a series of amazing movements with this function, so after the WS-20 equipped with WS-15, the maneuverability of fault will be strengthened.
The powerful performance of the F22 is largely derived from two powerful F119 engines, so the WS-15 will have to refuel.
The reliability of the WS-15 engine is also much better than that of the WS-10 and AL-31FN-M1. From now on, the WS-10 and AL-31FN-M1 are all in the first 500 hours and the flight hours are 1500 hours. And the 117S three generations of improved engines have reached 1000 hours of first turn, 4000 hours of flight hours, and the average maintenance interval of the F119 turbofan engine is twice as high as that of the third-generation turbofan engine, so the first turn, the flight hours are three generations of engines. To be high, so that after the WS20 is equipped with WS-15, it is guaranteed that the aircraft does not need to change the engine frequently, improve the utilization rate of the aircraft, ensure the training flight time, and enhance the combat capability of the troops. Go back to Sohu and see more
