The successful development of the "Taihang" engine marks that our country has entered the ranks of the world's aviation powers. "Kunlun" is majestic and "Taihang" is vast - the development path of my country's aviation engines
A country cannot be independent. Without the research and development of the aero-engine industry, there will be no independent aviation industry; without the advanced aero-engine industry, there will be no advanced aviation industry. In the past 30 years of reform and opening up, my country's aviation industry has achieved great success with the successful development of the "Taihang" engine. The "three major leaps" in my country's military aerospace engines from the second generation to the third generation, from turbojet to turbofan, and from medium thrust to high thrust indicate that our country has the ability to independently develop high-thrust military engines. The engines installed on our military's main combat aircraft have begun to get rid of the passive situation of being controlled by others. This is a historic breakthrough and has greatly enhanced our country's military strength.
The aviation industry is a knowledge-intensive and technology-intensive high-tech industry. Aviation engines are typical technology-intensive and high-value-added high-tech products. They have to work repeatedly for a long time under harsh conditions such as high temperature, high pressure, high speed and high load. They are required to be light in weight, small in size, safe, reliable and economical to use. Therefore, it must be exquisitely designed, precisely processed, and made of high-performance materials. It is technically difficult, requires a lot of investment, has a long cycle, and is risky. There are many countries in the world that can engage in aircraft manufacturing, and they can independently develop aviation. Only a few countries, such as the United States, Britain, Russia, and France, have developed the core technology of military aviation engines, and developed countries have implemented strict blockades. It is an inevitable choice for our country to take the road of independent development of aerospace engines.
In the early 1960s, in order to break the international technological blockade on our country and independently develop our country’s cutting-edge aerospace power technology, we established the Shenyang Aviation Industry Corporation of my country. A large number of entrepreneurs from the Shenyang Engine Design and Research Institute of China Aviation Industry Corporation, with the persistent ideal of serving the country through aviation, gathered in Shenyang to start the arduous battle.
The "Kunlun" engine has gone through many experiences since June 1984. From the verification aircraft to the development stage of the prototype, the military requires that the aircraft should not be modified in principle. It requires that the outer dimensions, air flow, and installation form of the "Kunlun" remain unchanged compared with similar engines currently in service; It is developed in strict accordance with the model specifications compiled by the national military standards, which means that it must step up to the level of international advanced standards, requiring the "Kunlun" to have large thrust, low fuel consumption, and good reliability and maintainability.
By the beginning of 1991, the "Kunlun" engine designed by China Air Force had adopted many new technologies in accordance with the requirements of the Air Force, and had undergone two major design modifications, including the compressor rotor blades and turbine. Key technologies such as blade breakage.
The biggest problem encountered in the development of "Kunlun" is that the high-pressure compressor and the low-pressure compressor do not work well due to insufficient compressor surge margin. The research team spent more than three years improving the surge margin of the low-pressure compressor by modifying the design.
In April 1991, our army's new aircraft selected the "Kunlun" engine as the power plant and was included in the national key models to accelerate development. On December 12, 1993, the "Kunlun" made its first flight successfully. This was a memorable day in the history of China's aviation industry. Half a year after its first flight, the research team went through many design modifications and tests. Finally, the high-pressure compressor adopted high-expansion and stability-gain casing processing technology and replaced the "bleeding" device with a new structure, finally overcoming the problem that had troubled the "Kunlun" for many years. The high and low pressure air machines do not match this important technical key.
"The first flight is not easy, and finalization is even harder." "Kunlun" is the first engine developed in accordance with the national military standards. In order to meticulously implement the national military standards and model specifications, the research team is determined to compile a materials manual that meets the requirements.
They collaborated with more than 20 units including the First Air Materials Institute, and spent 8 years editing and publishing my country's first " "Material Data Manual for Aero-Engine Design" not only solved the urgent need in the development of "Kunlun", but also laid a solid foundation for future aero-engine design.
After several years of hard work, tens of thousands of hours of component testing, and thousands of hours of complete machine testing, the research team has successively eliminated hundreds of problems such as excessive engine vibration, turbine guide blade ablation, and flame tube cracks. A technical glitch. It successfully passed the first component test of rotor over-rotation and rupture, low-cycle fatigue, and complete engine test run for a newly developed engine in China, as well as the environmental test of all accessories.
During the high-altitude and high-Mach test flights of the "Kunlun" in the fourth quarter of 1997, the engine experienced surge shutdowns three times. At the flight test site, the research team first conducted a water spray surge test on the "Kunlun" to further assess the surge margin. Every detail from working principle to equipment selection, material selection, water heating, antifreeze, filtration, testing, support structure, etc. is strictly controlled. After more than 20 days of intense water-spraying test runs, the cause of the fault was clarified, and finally the major technical key of high-altitude high-Mach speed parking, which usually takes at least a year to solve, was completely overcome in only 4 months.
The research team learned from internationally advanced film cooling technology and boldly adopted composite air-cooled hollow turbine blades. This blade is known as the "crown jewel" of modern aero-engine technology. It includes not only advanced design technology and high-temperature material technology, but also directional solidification technology, no-margin precision casting technology, five-coordinate CNC drilling technology, abrasive flow finishing technology, non-destructive testing technology, cooling test technology, and high-temperature coating technology. In order to conquer the cutting-edge technology of composite air-cooled hollow turbine blades, the First Air Power Research Institute formed a "national team" and gathered the best domestic experts in design, materials, technology, processing, testing, etc. to develop it. After 8 years of research, improvement, testing, improvement, and testing again, we finally mastered this cutting-edge technology. On December 20, 1997, my country's first self-designed "Kunlun" high-performance dual-rotor afterburning turbojet engine with independent intellectual property rights was finally successfully trial-produced.
Blue Sky Monument Says "Taihang"
A few days ago, my country's self-developed high-thrust turbofan engine "Taihang" passed the design finalization review, which aroused strong repercussions inside and outside the industry, and also caused International attention.
In 2005, Yihang Power Research Institute finalized the design of the "Taihang" engine, which not only achieved a great leap in technical level, but also achieved a great leap in product performance. The third-generation turbofan engine not only greatly improves the total pressure ratio compared with the second-generation turbojet engine, but also greatly improves the use temperature of materials compared with the second-generation engine. At the same time, the machining accuracy requirements of the parts are also comprehensive. Improved. In this way, all participating research units of Air China will have to break through the difficulties of many "new materials" and "new processes" during the development process of the "Taihang" engine, carry out a large number of technical research, and at the same time carry out technological transformation in processing equipment. Since the turbofan engine has an external airflow, the matching of the overall engine parameters of the turbofan engine is quite different from that of the turbojet engine. In addition, since the temperature of the airflow entering the afterburner is lower than that of the turbojet engine, the temperature of the airflow entering the afterburner is lower than that of the turbojet engine. Tissue burning is also difficult. The component level of the third-generation turbofan engine has reached a higher level than that of the second-generation turbojet engine. Not only is the design difficult, but it also requires corresponding technical modifications in the test equipment.
The development of the "Taihang" engine went through an arduous process of 18 years. The aviation industry has gained a lot from the development of this model:
A product was produced. The "Taihang" engine was successfully developed, which solved the long-term problem of domestic aircraft power being controlled by others. For many years, Chinese aircraft have generally suffered from "heart disease", which means that the engine technology, which is the "heart" of the aircraft, is not strong enough. The "Taihang" engine is a high-thrust turbofan engine that belongs to the "third generation aircraft" level.
The successful development of the "Taihang" engine can provide power for several types of aircraft in our country, which to a certain extent alleviates the engine's constraints on aircraft development. The "Taihang" engine also builds a platform for us. On this platform, we can conduct research and development of the "Taihang" series of engines better and faster. We can also carry out pre-research on new engines more conveniently, greatly shortening the development time. cycle.
A way out. After 18 years of arduous research, we have embarked on the path of "putting ourselves first, being self-reliant, innovating and surpassing". Technically, including the design of components, the design of the system, the matching of the main engine and afterburner, the matching of the system and the engine, the matching of the engine and the aircraft, everything from technology, materials to processing has been independently developed, which has greatly improved the level.
Brought out a team. Members of this team include technical leaders at all levels, engine designers, model development managers, etc., all of whom have matured through the development of this model. Among them, the technical team is particularly worth mentioning. When the "Taihang" engine was first developed, most of the technical staff were college students who graduated in the 1960s. Through the development of "Taihang", the younger generation has grown up. Judging from the First Air Power Research Institute, from the designers to the chief designer, all are now college students who graduated in the 1980s.
Create a new model. The development of "Taihang" breaks the "one factory, one machine" model and engages in large-scale collaboration in specialized production. Since the development of the "Taihang" engine, more than 40 manufacturers have participated in the research. The participating research units have rushed to adopt new methods and new processes to overcome all difficulties in manufacturing with innovative thinking. They readily accepted the very difficult-to-process blades designed by Yihang Dynamics, organized research, produced qualified products, and improved their craftsmanship.
Form a spirit. "Taihang" has formed the spirit of "unswerving determination, innovation and transcendence" through 18 years of research. All the research participants are full of love for the aviation industry of the motherland. They always have a high degree of professionalism, dedication, innovative spirit and rigorous scientific attitude. They work hard, study hard, and devote themselves wholeheartedly to model development.
During the development process of the "Taihang" engine, it encountered various technical problems and more than 200 failures, such as the fracture of the first-stage working blade of the fan. The "shoulder" design was changed, the tenon design and the Various measures such as damping have been taken to solve the problem. Bearing failure, solve the problem by improving lubrication. The problem of high oil return temperature at the rear fulcrum of the turbine was solved mainly by taking measures in the "air system".
In the development process of the "Taihang" engine, the design focused on maintainability quality, adopted unit structure design technology, and set up complete status monitoring means to provide convenient support facilities. In the major design of several key components, integrated innovation was carried out, dozens of new technologies, new materials and new processes based on pre-research were selected, and pre-research results were combined with model development to overcome multiple technical key points. While continuously increasing engineering experience, it has mastered internationally advanced engine design technology. The new technologies adopted by the "Taihang" engine in the self-design process include a three-stage fan with a transonic aerodynamic design with variable inlet camber guide blades; a two-stage low-pressure turbine with a three-dimensional aerodynamic design of compound tilt and torsion; a two-stage low-pressure turbine The guide blades of each stage are hollow, triple integral precision-cast structures, and rotate in counter-rotation with the high-pressure turbine. Its efficiency has reached the current international advanced level; the "Taihang" engine composite material outer casing is the first step of composite material technology in domestic aviation engines. First time application. The weight of the composite outer casing is reduced by 30%; the afterburner is of the "parallel intake" type, with a wide working range, light weight, and small fluid loss. It adopts a divided pressure fuel supply scheme to ensure that the fuel supply is within the engine operating envelope. Reliable ignition and stability; the tail nozzle is a fully stepless adjustable convergence and diffusion nozzle design, filling a domestic gap.
The successful development of the "Taihang" engine has pointed out the direction for the future development of my country's aviation and military engines: First, we must increase the intensity of basic research work. Our country's engine design team is relatively weak in basic research and basic theory.
Therefore, we will inevitably be required to focus on new designs, new materials, and new processes in advance, and conduct a large number of research and experiments on structures, components, processes, etc. The second is to achieve rapid response in hardware production during the development of new machines. The development of a new type of engine needs to be divided into several batches. Our country currently takes about 3 to 4 years to complete one batch. In some developed countries, engine production time is only 6 to 9 months. If our hardware production cycle can be shortened, the successful development of the "Taihang" engine will be greatly advanced. The third is to continuously strengthen the construction of engine development talent team. Judging from the situation of the First Aviation Power Institute, the absolute number of technical personnel is small, and their proportion of the entire staff is also small. They cannot meet the requirements of the new situation in engine development. This team should be further strengthened.
Passion transcends innovation
China First Aviation Liming Aviation Engine (Group) Co., Ltd. is the main enterprise in the production of aviation engines in my country. They have a deep understanding and unique insights into technological innovation.
While working at Liming Company, General Manager Lin Zuoming established turbine manufacturing technology as the core manufacturing technology and led the company on the road to revitalizing the enterprise through technological innovation. There are three sources of technology for Yihang Liming, namely independent innovation, technology introduction, and cooperative development. It has formed an innovation system that combines multiple forms of technology sources.
While AVIC attaches great importance to the development and production of military aircraft engines, it also attaches great importance to international cooperation. From the early 1980s to the present, subcontracting production has evolved from undertaking small-scale production of small parts on military production lines It has developed to the establishment of a specialized subcontracted production factory, and the output value has also increased from the initial annual foreign exchange earnings of tens of thousands of dollars to the current annual foreign exchange earnings of tens of millions of dollars. Carrying out international cooperation has promoted the improvement of scientific and technological innovation capabilities and learned many technical and management experiences from the world's advanced aerospace engine companies.
The materials used by Yihang Liming in the development and production of the "Taihang" engine have been based in China and have been localized. The research on materials has achieved certain results, but there are also some problems: the development of new engines The cycle is long. Due to reasons such as mixed production lines between trial production and batch production, insufficient coordination between design and process, and technical quality issues that cannot be dealt with in a timely and effective manner, the scientific research trial production plan cannot be realized according to the node; the process performance of new materials needs to be further improved. GH4169 alloy compressor and turbine discs still have low performance margins, and in some cases the performance and structure of the discs cannot meet standard requirements; new processes and new structures require continuous improvement. The converging and expanding nozzle is a large thin-walled precision casting with high metallurgical quality and casting size requirements, and the initial pass rate of development is low. In response to the above problems, AVIC Liming established a "national team" of project experts to break industry barriers, join forces, complement each other's advantages, share the results, combine model development to cope with challenges, and resolutely overcome technical difficulties.
Pang Wei, chairman of Yihang Liming, believes that the long-term competitiveness of an enterprise can only be based on independent innovation of products. He regards technological innovation as the lifeline that determines the company's survival in the face of increasingly fierce market competition. , possessing the company's independent core technology and building its own brand have become the decisive factors for the company's survival.
As an aero-engine company, YHang Liming’s main products include aero-engines, series gas turbines, aviation subcontracts, etc. The company has a number of core technical expertise such as aero-engine assembly and testing technology, casing precision CNC machining technology, cold rolling no-margin blade processing technology, special process welding technology, and thermal spray surface treatment technology. Faced with such a large number of complex work points, the company has established three levels of technological innovation: first, facing the world, learning from others' strengths, carrying out technological transformation from a high starting point, and maintaining the leadership of process equipment; second, facing the market, constantly developing and developing high-tech products. New products with high content and high added value ensure that the products have high quality and low cost; thirdly, we are facing the future, seizing the commanding heights of aviation manufacturing technology, carrying out independent innovation, taking advanced research as the guide, and ensuring the advancement of aviation manufacturing technology.
Change is the core of technological innovation. In the past 50 years of technological development, Yihang Liming has accumulated and accumulated many excellent technologies. By absorbing the essence of the knowledge treasure house and analyzing its development rules, we can determine the direction of technological development.
Leap-over is the "fulcrum" of technological innovation. Although AVIC Liming currently has the capability to develop and repair third-generation aircraft engines, in order to quickly improve its technological innovation level, the company is vigorously conducting research on cutting-edge technologies for fourth-generation aircraft.
Integration is an important method of technological innovation. In recent years, AVIC Liming has strengthened the construction of technical sub-centers in Beijing, Shanghai, Dalian and Russia, established academician workstations and postdoctoral workstations, and established the "National Defense Science and Technology Industry Precision Casting Technology Research and Application Center" with the AVIC Materials Institute; the company Independently and jointly with Beihang University, we established the "Lingming-Beihang University's First Test Base Surface Engineering Center"; we participated in the "National Defense Science and Technology Industrial Automation Welding Technology Research and Application Center" and established an innovative technology research and development center with complementary advantages and shared resources. The system has been rationally reorganized to form a strong R&D strength. At present, the company's technological innovation system has formed a three-level system of advanced research layer, product design and process formulation layer, and on-site guidance service layer to continuously strengthen product improvement, modification design capabilities and the ability to accelerate response to market demand.
Yihang Liming further strengthens the foundation of engine manufacturing technology, enhances the ability of engine modification, life extension, and reliability growth, strives to improve the overall level, and establishes a complete product development, process testing, and rapid response integrated system. Technological innovation system.
In order to improve the technological innovation system and mechanism construction, Yihang Liming has built four platforms to form a synergy for technological innovation.
Build a technology output platform. A technology output platform with the technology center as the main body carries out pre-research and technology improvement work on cutting-edge technologies.
Build a professional COE platform. Transfer some professionals in product, process, and tooling design to the production line to enrich the production unit COE and form a specialized production unit technology application system based on professional development and typical characteristics of parts.
Build a rapid response platform. The first step is to integrate resources and achieve rapid response to tooling and some machine parts by creatively re-engineering work processes and management mechanisms. The second step is to build basic scientific research and testing facilities supporting rapid response based on key models and the technological transformation of the National Engineering Application Center.
Build a technological innovation platform. Breakthroughs in key technologies such as integral blisk manufacturing, powder metallurgy disk processing, wide-chord fan blade manufacturing, single-crystal no-margin blade precision casting, new sealing structural parts manufacturing, composite material component processing, and new thermal barrier coating coatings.
The successful development of the "Taihang" engine marks that our country has entered the ranks of the world's aviation powers. It is the reform and opening up that has pointed out the direction for the aviation engine industry. It is the fruitful result of the aviation concept of self-reliance and independent innovation to serve the country. The result is the strong voice of the times played by the passionate and enterprising spirit, and a bouquet of flowers presented by hundreds of thousands of aviation sons and daughters to their motherland.
The successful development of the two new engines "Kunlun" and "Taihang" has brought together the strength of China's aviation industry and all aspects of the country. Their contributions, like the majestic Kunlun and the vast Taihang, will surely inspire aviation people. Move forward courageously.