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"Liu, I would like to say the unfortunate news that although the GE36 turbine fan motor (UDF) developed by General Electric has successfully reached 128oo pounds of thrust, which is a little closer to the minimum thrust of 14ooo pounds we need, there is still no solution to the problem of excessive motor noise. ”

"We did a test and found that the noise in the middle of the cabin was not up to an acceptable level, even with the tail crane, so we started the backup plan at the right time and considered using the turbofan motor as the engine of the MPC75 airliner." Edmiston shook the information in his hand and said solemnly.

The GE36 fan engine is the original pre-installed power engine of the MPC75 airliner, and the core engine is derived from the F4O4 medium thrust engine of the F/A18 fighter equipped by the US Navy.

Affected by the oil crisis in the seventies, in the eighties, the world's aviation power system suppliers have begun to develop a new type of aviation motor, the most of which is the turbine fan motor (UDF), a Shijian global large aviation power group has launched the turbine fan motor, Rolls-Royce's RB3O11, Pratt & Whitney and Allison joint research and development of 578XD, GM's GE36, the Soviet Union's D27 are one of them.

The principle of the turbo fan motor is very simple, it is a turbofan motor with the outer duct removed, due to the almost infinite amplification of the outer duct, the fan motor has extremely low fuel consumption, and good propulsion, in order to ensure the O.7 Mach cruising at the moment. At least about 3o% more fuel-efficient than the turbofan motor of the same era.

However, in the 80s, the turbine fan motor had two weaknesses that were difficult to solve, one was limited to the limited computer power at that time, and the fan blades could not be analyzed and optimized, and the blade noise problem of the fan motor could not be solved, and the other was that the turbofan that rotated nearly 10,000 revolutions per minute was directly exposed, and the flight safety problem was very strict.

By the end of the eighties, after the technological breakthrough of the new generation of turbofan motor in the early nineties, this very fuel-efficient new aviation motor was shelved by most industrial groups, and finally only the Soviet Union's D27 turbo fan motor was officially installed and put into use.

Liang Yuan just made the power system of Mingbaimpc75, and suddenly became the reason for the turbofan motor.

Liu Wenyue's face was calm when he heard Edmiston finish speaking. Placid. Liang Yuan was keenly aware of the embarrassment on Jiang Qingmin's face, the leader of the MPC75 project team, and it was fleeting.

Liang Yuan rolled his eyes, and said in his heart that he would let Lao Liu investigate and investigate, it seems that the seventy or eighty people in the project team and the German guanxi are quite complicated.

After listening to a few words about the difference between the turbofan motive and the pulp fan motive between Edmiston and Liu Wenyue, Liang Yuan focused on the information in his hand again.

In the eyes of ordinary people. It can most intuitively reflect the technical level of large passenger aircraft. There is one of the simplest numbers, jù. Composite material usage ratio.

Generally speaking, the higher the proportion of composite materials used, the more advanced the technology level of the passenger aircraft platform itself. For example, the proportion of composite materials used in the ARJ217OO passenger aircraft of the Republic of China in the new century is only 2%, which is equivalent to the application level of composite materials in foreign countries in the seventies.

Boeing 787 and Airbus 35O, which represent the first-class level of Shijiè, have used more than 5O, but before Liang Yuan wears, A35O is still in service, and B787 is because of the use of too many composite materials, and the problem continues, and Kěnéng was grounded by the FAA and the Safe Transportation Committee.

In addition to these two extremely advanced examples, the use of composite materials for a large passenger aircraft reached 15%, which can definitely be classified into the advanced ranks, Boeing developed the B777 wide-body passenger aircraft at the end of the nineties The use of composite materials reached 11%, and the proportion of Airbus's A32O, A33O, and A34O composite materials is about 15%, even if it is an epoch-making A38O giant airliner, the proportion of composite materials is only 22%.

Due to the earlier reasons of the exhibition, the composite material application level of single-aisle narrow-body airliners is far less than that of large wide-body airliners, the proportion of composite materials in the second-generation Boeing 7373oo, 4oo, 5oo series, McDonnell Douglas 8O, 9O series is about 5%, and the composite materials of the third-generation Boeing 7377oo, 8oo, 9oo and other models, and even the final version of the future 737 737MAX The composite material use ratio is not close to 2O%.

Liang Yuan was stunned and looked at the schematic diagram and final ratio of the composite materials of the MPC75 passenger aircraft on the information in his hand, if it weren't for the excellent self-control ability of the two lives, Liang Yuan would have slapped the table and jumped up.

The history of the use of composite materials in large passenger aircraft can be roughly divided into four stages, the first stage in the seventies, composite materials began to enter the field of civil airliners on a large scale, the typical use of composite materials, for the passenger aircraft with very little force components, similar to the leading edge, inspection mouth cover, fairing, spoiler and other parts.

The level of composite material use of COMAC ARJ217OO is basically at this stage.

The typical part of the composite materials used in the second stage is the parts of the passenger aircraft with less stress, similar to the elevator, rudder, flaps, ailerons and other parts.

Boeing's second-generation 7372oo, 3oo, and 4oo are basically at this level.

The typical use of composite materials in the third stage is the part of the passenger aircraft with large stress, similar to the horizontal tail, vertical tail, motor nacelle and other parts.

Airbus's A32O is basically at this level, and it can be said that A32O can be successful in the encirclement and interception of the second-generation Boeing 737, in addition to the national will, the leading platform technology also has considerable factors.

After the rise of Airbus's A32O, Boeing, which learned from the pain, came up with the third-generation 7376OO, 7OO, 8OO and other models, so as to bring the technical level and A32O together.

The typical part of the composite material used in the fourth stage is the main load-bearing part of the passenger aircraft, similar to the main stress-bearing parts of the passenger aircraft such as the fuselage and wings.

Like Airbus' A38O, A35O, and Boeing's 787, Yijing has reached the fourth stage of composite use, but the A35O and B787 are more extreme.

The MPC75 regional airliner will be in the wings, vertical tail, and doors...... and other parts of the use of composite materials in a large area, up to 2o% of the weight of the aircraft structure. Looking at the words in front of him, Liang Yuan blinked vigorously.

No wonder this cargo pulled a lot and ran far, Liang Yuan pressed ziji's palm with his fingernails, confirming that zijiméiyou was dazzled.

At least Liang Yuan, who has seen the process of the large passenger aircraft exhibition in the next 3O years, knows that in Ziji's memory, together with Airbus and Boeing's exhibition plans before the 2O2O year, as far as the advanced xing of the platform is concerned, MPC75 is invincible in the field of short- and medium-haul narrow-body passenger aircraft, no wonder the Germans wrote at the beginning that even if it enters the new century, the MPC75 passenger aircraft will still be the technical leader of regional airliners.

Liang Yuan thought about the large-scale war of words between France and the Federal Republic of Germany that lasted for several years to build a second Airbus production line in Hamburg, and thought about the establishment of the BM/RR motor manufacturing company just a few days ago, and the Federal Republic of Germany announced in the newspaper that BMW would cooperate with Rolls-Royce to develop the RB7OO series turbofan engine with thrust at 6O9OKN.

In order to maintain Ziji's leadership position in the Airbus Group and maintain domestic jobs, the French repeatedly rejected the Federal Republic of Germany's request to increase production lines.

Thinking about the news of the merger of MBB and Mercedes-Benz Aerospace, the Federal Republic of Germany is really in the next big game.

Now the consequences are out, this MPC75 plan is obviously going to A32O, it seems that the Germans are ready to make up their minds to go it alone, otherwise they will never set the indicators of MPC75 so advanced, Liang Yuan thought about the countless bad debts between European countries, and almost laughed out loud, Ziji really picked up a big bargain. (To be continued......)