【Academician Interview】
◎Our reporter Jiao Yang
At present, the 1,000-kilowatt AES100 civil turboshaft engine independently developed by China Aviation Engine Group Co., Ltd. (hereinafter referred to as China Aerospace Engineering Group Co., Ltd.) is making the final sprint for independent airworthiness certification this year.
It is my country's first product with international competitiveness and completely independent intellectual property rights, and its technical level is comparable to the international fourth-generation advanced civil engine.
"We want to become a Chinese brand of civil aviation engines, make the most advanced engines, and let all Chinese aircraft use a strong 'Chinese heart'!" Yin Zeyong, academician of the Chinese Academy of Engineering and former director of the China Aviation Development Science and Technology Commission, recently accepted an interview with a reporter from Science and Technology Daily express.
China's aviation engine industry has made great progress
Reporter: Aviation engines are called the “crown jewel” of modern industry. Which countries in the world can develop advanced aero engines?
Yin Zeyong: Currently, the United States, Russia, the United Kingdom, France and China are able to develop advanced aviation engines. New China's aviation engine industry was born in the flames of the war to resist U.S. aggression and aid Korea, and relied on constant self-improvement. Through the unremitting efforts of generations of aviation engineers engaged in the aero-engine industry, my country's aero-engine industry has grown from scratch, from small to large, from weak to strong, and has realized advanced aero engines such as turbojet, turbofan, turboshaft, and turboprop. Development and production of series products.
Reporter: What is the current development status of China's aerospace engine industry? What representative products have emerged in recent years?
Yin Zeyong: The party and the country attach great importance to the development of the aviation engine industry. On September 1, 2023, General Secretary Xi Jinping wrote a special reply to the employees of the "Li Zhiqiang Class" of China Aviation Development Corporation, pointing out that "in recent years, China's aviation engine industry has made great progress, and has initially explored a new path for independent innovation and development." This is a high-level summary and praise of the achievements in the aero-engine industry.
Aviation engines have made great progress over the years. In terms of civil engines, at air shows in recent years, China Aviation Development Corporation has successively exhibited large bypass ratio turbofan commercial engines such as CJ (Yangtze River) 1000A and CJ2000, turboshaft and turboprop navigation engines such as AES100 and AEP100, and other types of new engines. . These are concrete manifestations of the great progress made in my country's aerospace engine industry.
Reporter: At what level are these engines you mentioned?
Yin Zeyong: Take the large aircraft-powered Yangtze River series engines that Chinese people are concerned about as an example. I was the first chief designer of this series of engines. At the beginning of the project, the goal of my team members and I was to benchmark against world-class standards and build the most advanced engine. After years of hard work, this series of engines has made significant progress.
Reporter: What aircraft are the Yangtze series engines specifically equipped with?
Yin Zeyong: The CJ1000A engine can meet the power needs of 150-seat single-aisle aircraft and will be the strong "Chinese heart" of commercial aircraft. The CJ2000 engine is targeted at equipping dual-channel long-range wide-body passenger aircraft. These two types of large bypass ratio engines have completely independent intellectual property rights, and have low fuel consumption, low emissions, low noise, high reliability, and long life. They can also be developed in series through improvements and modifications.
Unswervingly adhere to the concept of independent research and development
Reporter: There was a saying that “one generation, one type of aero engine”. Why does it take so long to develop an engine?
Yin Zeyong: The development of aeroengine is a complex system engineering that integrates the latest achievements of modern science and technology in aerodynamics, combustion, structural strength, control, machinery, materials, etc. The requirements for engine use are also particularly demanding. Engines need to work reliably for a long time in complex environments such as high temperature, high cold, plateau and salt spray. Its design, manufacturing and testing workload is extremely heavy, so the development cycle is long.
Reporter: With the emergence of new mechanisms and new technologies, will my country's engine development cycle be shortened?
Yin Zeyong: The pace of independent research and development of aviation engines in our country is constantly accelerating. Especially in 2016, after the party and the state approved the establishment of China Aviation Development Corporation, many key core technologies achieved breakthroughs.
What I deeply appreciate is that all members of the research and development front faced difficulties, dared to fight hard, and adopted many innovative ideas and methods.
For example, we focus on strengthening application basic theoretical research, common technology research and model pre-study, and closely integrate with model development; strengthen the development of key parts and key accessories such as blades, discs, control systems, bearings; strengthen testing capabilities, production Capacity and support capacity building, etc. Our work is pragmatic and effective, ensuring a significant improvement in engine technology and a significant shortening of the development cycle.
Reporter: What efforts have we made to speed up the development of domestic aircraft engines?
Yin Zeyong: The most important effort we make is to persist in the concept of independent research and development. Over the years, we have overcome many difficulties and proactively established an independent innovation R&D process, vigorously applied simulation technology, established and improved a sound quality management system, promoted the implementation of "first-time success" projects, and promoted the "one-install-one-test" assembly mode conversion. Design, testing, and manufacturing levels continue to improve, and the research and development cycle continues to shorten.
In the past eight years, a number of new engines have successfully made their first flights, a number of key models have been identified and finalized, a number of key technologies have been successively conquered, and the development of a number of core equipment is accelerating.
It takes ten years of perseverance to sharpen a sword
Reporter: What conditions are needed to develop a high-tech engine?
Yin Zeyong: If you want to independently develop an aerospace engine with advanced technology and reliable quality, you need scientific development methods, advanced technical means and an innovative and pragmatic R&D team. Of course, it also requires a lot of resources and the perseverance to sharpen the sword for ten years.
In the 1970s and 1980s, my team members and I innovatively researched and applied advanced numerical analysis methods in engine design. This is also one of the important methods of design analysis now and is crucial to accelerating independent innovation and development.
From the method research that year to the day when the team successfully developed our own universal design optimization industrial software, this process was very arduous and one would not be able to persevere without perseverance.
Reporter: What innovative measures have we made in terms of capacity building?
Yin Zeyong: In recent years, relevant departments have increased their support. We have accelerated the progress of equipment construction, and a number of advanced test facilities such as the newly built aero-engine high-altitude simulation test base and aero-engine open-air test bench have effectively guaranteed the development of advanced engines.
We also made full use of the advantages of the new nationwide system to gather national strength and form a "national team." For example, the establishment of the China Association for Science and Technology Aviation Engine Industry-Academic Consortium has formed a basic pattern of integration and innovation.
Reporter: In 2016, the "Yulong" engine was exhibited for the first time. This new turboshaft engine was completely designed and developed independently in my country and won the first prize of the National Science and Technology Progress Award. This is the highest national award that my country's aerospace engine has independently applied for. What is the significance of the successful research and development of the "Yulong" engine to China's aviation engine industry?
Yin Zeyong: "Yulong" is my country's first turboshaft engine that has gone through the entire process of independent innovation, R&D, application and development. It has fundamentally changed the development method of my country's turboshaft engines and achieved an essential leap in the technological level of turboshaft engines from the introduction of foreign patented production to the completely independent innovation and research and development of advanced engines.
As the chief designer of this engine, I think the more important significance of its successful development is that it proves that we dare to think, dare to do, and dare to win. What foreigners can do, Chinese people can not only do, but also do better.
Reporter: It has been 40 years since the development of the "Jade Dragon" engine was launched in 1984. In this process, the "Jade Dragon" spirit has been condensed. What is this specifically?
Yin Zeyong: This year coincides with the 40th year of R&D, use and development of the "Yulong" engine. I have personally experienced and witnessed the continuous development of the "Yulong" engine. In its pre-research, design and development, batch installation, improvement and modification development process, the "Jade Dragon" spirit of "down-to-earth, independent and self-reliant, persistent and determined to transcend" has been condensed and formed. This spirit inspires us to develop more independent innovative advanced engines.
Reporter: Currently, is the "Yulong" engine still being upgraded and iterated?
Yin Zeyong: In recent years, the development team has continued to improve and upgrade. The performance and service life of the "Yulong" engine have far exceeded the finalization requirements. Moreover, the team has further innovated and developed a series of advanced engines, such as the AES100, the most advanced fourth-generation civilian turboshaft engine developed by the team. In addition, there are corresponding turboprop and turbofan engines.
The advancement of the engine can be evaluated from many aspects
Reporter: You have been engaged in the development of aerospace engines for a long time. In your opinion, what is the standard for an advanced engine?
Yin Zeyong: I entered the aviation field in college in 1962. After graduation, I entered the aero-engine industry and have participated in the development of multiple types of turbofans, turboshaft and turboprop engines, and helicopter transmission systems.
In my opinion, whether a type of engine is advanced or not can be generally judged from aspects such as design, manufacturing and use effects.
Only by using the most advanced manufacturing technology can we build a good engine. For example, turbine blades are the "core of the core" of an engine. To produce an engine with high thrust (power) and high thrust (power)-to-weight ratio, the temperature in front of the turbine must be increased. At high temperatures, the durability, creep strength, thermal fatigue resistance and other properties of the turbine blade material are the basis for its long-term operation and are one of the indicators for judging whether an engine is advanced or not.
Reporter: You mentioned that the performance of turbine blade materials in high-temperature environments is the basis for their long-term operation. So, what are the currently used metal materials with good thermal strength properties?
Yin Zeyong: Currently, the metal material with good thermal strength properties is nickel-based single crystal alloy. In the process of developing the "Yulong" engine, we were the first in China to develop and manufacture the most advanced single-crystal alloy blades, overcoming a series of difficulties such as material preparation and blade processing, ensuring the advanced nature of the "Yulong" engine.
Reporter: Will the development of turbine blade materials "rise all boats" as the temperature in front of the turbine increases?
Yin Zeyong: Yes. From high-temperature alloys to directional alloys to single-crystal alloys and ceramic matrix composites, the birth of each new material has improved the thermal performance of turbine blades.
However, there is always a maturation process for new materials. When developing the "Yulong" engine, we used single-crystal high-temperature alloys, which greatly improved engine performance. Now, we are studying ceramic matrix composite blades with better thermal strength.
Reporter: From the perspective of engine use, how do you think we should choose between technological advancement and cost-effectiveness?
Yin Zeyong: The most suitable one is the best. There are many types of aircraft, with different requirements for each type of engine. Starting from the needs of aircraft users, a good engine can not only meet the needs of use, but also be economical and reliable.
If the engine only meets the narrow definition of technological advancement, but the cost is high, the use and maintenance are inconvenient, and users cannot afford it, it will not be competitive.
The advancement of the engine also includes economy and maintenance. A lot of work has been done to promote economy and maintainability of the AES100 engine. I guided the team to develop turboshaft, turboprop, turbofan engines and gas turbines based on its advanced universal core engine, which has great economic advantages.
Reporter: Please talk about the future development trend of aerospace engines.
Yin Zeyong: In the future, aviation engines must meet the carbon neutrality requirements of peak carbon emissions. Today, the direction of civil engine technology innovation is changing from incremental reforms to improve thermal efficiency and reduce carbon emissions to revolutionary changes to develop new low-carbon propulsion technologies and new fuels. Among them, sustainable aviation fuel, new hybrid propulsion technology, hydrogen power technology, etc. have become the most representative disruptive technologies.
Reporter: What research does China Aviation Development have in this area? how is the progress?
Yin Zeyong: I said before that if we want to do something, we must make the most advanced engine. In recent years, in order to achieve the "double carbon" goal, we have systematically laid out cutting-edge subversive technologies, accelerated research on new energy sources such as hydrogen energy and hybrid electricity, and new-principle aviation power technologies, and strived to seize the commanding heights of cutting-edge power in the future.
[To young scientific and technological talents]
Young scientific and technological talents should first have "feelings for family and country." Along the way, the most correct choice for me was to follow the party and contribute to the country. Without this feeling of integrating individuals into the cause of the party and the country, it is impossible to achieve anything.
You must have the determination to dare to be the first. I have served as the chief engineer of many models, and I have always believed that what I want to do is to make the best engine. We must have the courage to admit and face our temporary backwardness, but we must never fail to make progress, and we must not repeat low-level, uncompetitive engines.
We should use scientific innovation as the driving force, break out of the limitations of the rules and regulations, and continue to make breakthroughs in exploration. I think an outstanding engineer should be a lifelong learner, have a broad foundation, and pay attention to the cross-integration of knowledge between different disciplines. "National important weapons" are complex large-scale system projects. Whether you are working as a chief engineer or undertaking specific technical work, you must have systematic thinking and perseverance. ——Yin Zeyong
(Science and Technology Daily)