The vast number of scientific research personnel of Taihang engine have studied hard and repeatedly attacked, and have successively overcome dozens of major technical keys. In 2003, the development of Taihang engine entered the decisive battle stage. Because there is still a big gap in understanding and grasping the law of engine development, there are also some problems in quality management and work style, and the development work has been in trouble several times. It has gone through two major tests: first, the fourth wheel disc of the high-pressure compressor broke during the engine test run; The second time was in the high altitude platform simulation test and adjustment flight test, which exposed some technical problems, such as the slow acceleration of the high altitude small platform speed engine. During the flight test from late August to early September, 2003, there were three "special circumstances" in five take-offs and landings. In the summer of 2004, Taihang engine stopped in the air during the specified test flight. Although he finally returned safely, the development of Taihang engine was passive. 606 Institute analyzed the troubleshooting countermeasures together with experts inside and outside the industry, further improved the fault research and analysis, successively completed the 17 fault calculation, research and analysis report, and finally resumed the flight test of Taihang engine. Many technical problems encountered in flight test, such as ground surge, abnormal noise in the air, abnormal test temperature and early separation of small engines, have been solved.
In the process of engine trial-production, China No.1 Airlines creatively studied and applied foreign advanced experience, broke the management mode of one factory and one machine in the past, gave full play to the advantages of various domestic specialties, and a number of enterprises formed a national joint research team to jointly tackle key problems and successfully applied hundreds of new materials and technologies. Engine materials have approached or reached the international advanced level. Advanced new materials account for more than 50% of the weight of the whole machine. Including advanced titanium alloys, advanced superalloys and high specific strength-high temperature resin matrix composites used in domestic engines for the first time.
New technologies adopted in the development of Taihang engine include:
1) The three-stage fan is of transonic aerodynamic design, with imported variable camber guide vanes supported by cantilever and no imported variable camber guide vanes; Superplastic forming diffusion connection inlet box is a new breakthrough in this design technology in China. 2) The two-stage low-pressure turbine is a three-dimensional aerodynamic design with compound tilting, bending and torsion. The two-stage guide vanes of the low-pressure turbine are hollow triple integral precision casting structures, which rotate in the opposite direction to the high-pressure turbine, and the efficiency has reached the international advanced level. 3) Taihang hollow blades, 606 experts from the best domestic design, materials, technology, processing, testing and other aspects have become a "national team". After eight years of painstaking research and experiments, they finally mastered this cutting-edge technology called the "crown jewel" of modern aero-engines. Drawing lessons from the international advanced film cooling technology, composite air-cooled hollow turbine blades are boldly adopted. It includes not only advanced design technology and high-temperature material technology, but also directional solidification technology, precision casting technology without allowance, five-axis NC drilling technology, abrasive polishing technology, nondestructive testing technology, cooling test technology and high-temperature coating technology. 4) "Taihang" engine composite external culvert casing is the first application of composite technology in domestic aero-engines. It is the fourth generation engine technology abroad, which fills the gap of domestic aero-engine technology; The composite outer culvert is 30% lighter than that of welded titanium plate structure, with higher specific strength and stiffness, longer fatigue life and more corrosion resistance. 5) The afterburner is of "parallel air intake" type, with wide working range, light weight and small fluid loss. The partial pressure oil supply scheme is adopted to ensure the reliable ignition and stability in the engine working envelope; 6) The stator blades of four or eight high-pressure compressors have been cold-rolled for the first time in China. The successfully developed cold rolling of GH4 169 alloy IV-VIII stator blades fills the gap in the domestic cold rolling technology of superalloy blades. By the end of February 2004, 65438+ had completed tackling key problems and was in the leading position in the world. However, the performance richness of GH4 169 alloy compressor and turbine disk is still small, and the performance and structure of the disk can not meet the standard requirements in some cases. New technologies and new structures need continuous improvement. 7) The tail nozzle is designed as a fully stepless adjustable convergent diffusion nozzle, which fills the gap in China. However, the average qualified rate of convergent-divergent nozzle investment castings is only 54%, which needs to be further improved. 8) The electron beam welding of the turbine rear shell of Taihang aero-engine is impeccable in both process arrangement and parts delivery quality. 9) Nano-zirconia technology is applied to thermal barrier coating, which puts on a layer of "protective clothing" with excellent and stable performance for the high-pressure turbine guide blades and low-pressure first-and second-stage guide blades of Taihang engine, reaching the forefront of the application of thermal barrier coating technology in the world. In May, 2005, the engineering of this technology was completed, and it was applied to "Taihang" engine blades. In August, 2005, the high-pressure turbine guide vane sprayed with nano-zirconia thermal barrier coating technology solved the ablation problem and successfully passed the long-term test run of Taihang engine. 10) It is the first time to adopt an integral casting titanium alloy intermediate shell; This technical problem was finally solved by Beijing Institute of Aeronautical Materials.
1 1) the control system used in the initial test of Taihang engine was a digital electro-hydraulic system, but its stability, reliability and anti-interference were not mature enough, so it was changed to a mechanical hydraulic scheme./kloc-0 was installed in February, 1998. After strict examination and verification, it can ensure the reliable operation of the engine. The original digital electro-hydraulic control scheme is changed to the second scheme, which will replace the mechanical hydraulic control scheme when it matures. 12) in the development stage of Taihang engine prototype, new powder metallurgy materials were used for high-pressure turbine disk, but because the related technologies in China are not yet fully mature, this material has been replaced since the finalization batch.