CR929 passenger plane jointly developed by China and Russia
Recently, it is reported that AVIC Hi-Tech has made great progress in the use of composite materials and completed the development of composite blades for CJ2000 turbofan engines, marking another technological breakthrough in the development of domestic aviation engines.
Relevant news said that CJ2000 is a new generation of domestically produced commercial aviation engines, which should be a domestic CJ1000 engine development type. It may be the engine supporting domestic CR929 passenger aircraft.
Engines developed for CR929 in China
CR929 passenger aircraft is a new generation of wide-body passenger aircraft developed by China and Russia for the 2020 civil aviation market. As new passenger aircraft such as the Boeing 787 and A350 already exist in this field, the competition is very fierce, requiring the CR929 passenger aircraft to have better economy and reliability, and correspondingly more demanding engine requirements.
Therefore, when the relevant units developed the CJ2000, they adopted a series of new technologies to improve engine performance, including composite blades.
For passenger aircraft, the best way to improve economics and reliability is to reduce the structural weight, which is largely determined by the engine. Modern airliners are equipped with large ducted turbofan engines, and the weight of the fan section occupies 40% of the total engine weight. In this way, reducing the weight of the engine fan can effectively reduce the weight of the entire engine, and further reducing the weight of the passenger aircraft structure. According to relevant data, the weight of a modern large ducted turbofan engine fan blade is reduced by 1 kg, and the transmission system and the casing can also be reduced by 1 kg. The engine weight is reduced by 1 kg, and the overall weight can be reduced by 1 kg. It can be said that the effect is very obvious. Therefore, the new generation of large ducted turbofan engines abroad uses composite material fan blades.
CJ2000 engine may be similar to or similar to GENX engine
Composite fan blade
However, the development of composite fan blades for large ducted turbofan engines is extremely difficult. When the fan rotates at high speed, the centrifugal force and aerodynamic load are very large. In addition, factors such as foreign object impact must also be considered.
Therefore, composite fan blades have extremely high requirements on aerodynamics, composite materials, and process equipment. At present, composite fan blades are only mastered by a few developed countries such as the United States and Britain, and even Russia has not fully mastered this technology. The latest civilian turbofan engine PD-14 still uses titanium alloy fan blades.
Relevant domestic units are also in the tackling phase in this field. According to relevant data, the latest domestically produced large ducted turbofan engine-CJ1000 still uses titanium alloy fan blades. Considering the development trend of foreign advanced engines, domestic related units have adopted composite material fan blades as the key technology to solve the problem. After the unremitting efforts of the vast number of technical personnel, a series of technological breakthroughs have been made in the relevant fields, especially in the key composite materials. Grade carbon fiber has laid a solid foundation for the development of domestic composite fan blades. Taking advantage of the previous technological achievements, domestic related units launched an impact on composite fan blades. First, the technology of composite blades for aeroducts with small ducts was defeated, and then composite blades with large ducts were developed. After efforts to equip the successfully developed CJ2000 turboduct turbofan blade, this has cleared a major obstacle for the development of the whole machine.
The use of composite fan blades will improve the economy of CR929 passenger aircraft
The maximum take-off weight and passenger capacity of the CR929 passenger aircraft are equivalent to those of the Boeing 787 passenger aircraft. Therefore, the size and parameters of the CJ2000 engine should be comparable to or similar to those of the American GE Corporation GENX. The latter fan has a diameter of up to 3 meters and uses a wide-chord swept blade made of carbon fiber reinforced epoxy resin composite material. In order to improve the resistance to foreign body impact, the leading edge of the blade is developed from titanium alloy. It is extremely difficult to develop such a fan blade, but the benefits are also very obvious. It can reduce the weight of the CJ2000 fan section by about 200 kg, plus the transmission system and the casing can reach 500 kg. As a whole, the engine is reduced by 500 kg, and the wing / body structure can also be reduced by 500 kg. In this way, the weight of the CR929 passenger aircraft structure is expected to save about 1 ton, thereby ensuring the economy and reliability of the aircraft.
The popularity of composite fan blades in domestic engines is just around the corner
Because the diameter of the CJ2000 large ducted turbofan engine fan is the largest among aero engines, it is also the most difficult. Therefore, we have mastered the composite blade technology of the CJ2000 engine. Smaller blades are not a problem. The popularity of composite fan blades in domestic aviation engines is just around the corner.