"Liu, I want to say unfortunate news. Although the GE36 turbofan engine (udf) developed by General Electric successfully reached 12,800 pounds of thrust and was closer to the minimum thrust we needed, the troublesome engine noise problem still shows no signs of solving it."

"We did the test. Even if we chose the tail hoisting method, the noise in the middle of the cabin was not acceptable. Therefore, we started the backup plan in time and considered using the turbofan engine as the engine of the mpc75 passenger plane." "Fiction chapter." Edmiston shook the information in his hand and said solemnly.

The ge36 pulp fan engine is the original pre-installed power engine of the mpc75 passenger aircraft. The core aircraft comes from the F/A18 fighter medium thrust engine F404 equipped by the US Navy.

Affected by the oil crisis in the 1970s, in the 1980s, global aerodynamic system suppliers began to develop new types of aero engines, the most realized one was the turbocharger fan engine (udf). Large aerospace power groups around the world launched turbocharger fan engines, Rolls-Royce's RB3011, Pratt & Whitney and Allison's 578xd, General Motors' GE36, and Soviet D27 are one of them.

The principle of the turbo fan engine is very simple. It is a turbofan engine that removes the outer duct. Due to the nearly infinite amplification of the outer duct, the slurry fan engine has extremely low fuel consumption and good propulsion speed. At a speed of 0.7 Mach cruising speed, it saves at least about 30% of fuel than the contemporary turbofan engines.

However, in the 1980s, there were two difficult weaknesses in the turbocharged fan engines. One was that the supercomputer's limited capabilities at that time were unable to analyze and optimize the fan blades. The blade noise problem of the pulp fan engine was never solved. The second was that the turbocharged fan with a speed of nearly 10,000 revolutions per minute was directly exposed, and the flight safety problem was very serious.

By the end of the 1980s and the technological breakthrough of the new generation of turbofan engines in the early 1990s, this very fuel-efficient new aircraft engine was successively shelved by most industrial groups. In the end, only the Soviet Union's d27 turbofan engine was officially installed and put into use.

Only then did Liang Yuan get the power system of mingbáimpc75, which suddenly became a turbofan engine.

After hearing Edmiston's words, Liu Wenyue's face was calm and calm. However, Liang Yuan keenly discovered that the embarrassing spirit on Jiang Qingmin's face, the head of the mpc75 project team, was fleeting.

Liang Yuan turned his eyes and said to let Lao Liu investigate and investigate carefully. It seemed that the project team's No. 70 and No. 80 and the German guānxi were quite complicated.

After listening to a few words about Edmiston and Liu Wenyue talking about the difference between turbofan engines and slurry fan engines, Liang Yuan focused his attention on the information in his hands.

In the eyes of ordinary people, the most intuitive way to reflect the technical level of large passenger aircraft is the simplest data. The ratio of composite materials used.

Generally speaking, the higher the proportion of composite materials, the more advanced the technical level of the passenger aircraft platform itself. For example, the proportion of composite materials used by the arj21700 passenger aircraft developed by the Republic in the new century is only 2%, which is equivalent to the level of composite materials used in foreign countries in the 1970s.

The proportion of composite materials used by Boeing 787 and Airbus 350, which represent the first-class standards, exceeded 50%. However, before Liang Yuan passed through, the a350 was still in service, and the b787 was used too much, which caused constant problems. It was extremely grounded by the Federal Aviation Administration and the Safety Transportation Commission. It can be said that the technology of large passenger aircraft using more than 50% of composite materials is still mature.

In addition to these two extremely advanced examples, the use ratio of a large passenger aircraft composite material reaches 15%, which can definitely be classified as advanced. The use ratio of the b777 wide-body passenger aircraft composite material developed by Boeing in the late 1990s reached 11%, and the use ratio of Airbus' a320, a330, and a340 composite material is about 15%. Even for the epoch-making a380 giant passenger aircraft, the proportion of composite material is only 22%.

Due to the early development, the application level of composite materials of single-channel narrow-body passenger aircraft is far inferior to that of large wide-body passenger aircraft. The proportion of composite materials of the second-generation Boeing 737300, 400, 500 series, and McDonnell 80, 90 series are all around 5%. The proportion of composite materials of the third-generation Boeing 737700, 800, 900 and other models, and even the ultimate version of the 737 max in the future has not reached nearly 20%.

Liang Yuan looked at the schematic diagram and final proportion of the composite material used by the mpc75 passenger plane in his hand in a daze. If he had not had the excellent self-control ability of two lifetimes, Liang Yuan would have already slapped the table and jumped up.

The use history of composite materials in large passenger aircraft can be roughly divided into four stages. The first stage was in the 1970s, and composite materials began to enter the field of civil passenger aircraft on a large scale. The typical use of composite materials is components with very little stress on the passenger aircraft, such as the leading edge, inspection cover, fairing, spoiler and other parts.

The level of composite materials used by COMAC in the Republic of China is basically at this stage.

The typical use of composite materials in the second stage is components with less stress on the passenger plane, such as elevators, rudders, flaps, ailerons, etc.

The entire series of Boeing's second-generation 737200, 300, and 400 are basically at this level.

The typical use of composite materials in the third stage is parts that are parts that are subject to greater stress by the passenger aircraft, such as horizontal tail wings, vertical tail wings, engine nacelles, etc.

Airbus' A320 series is basically at this level. It can be said that the a320 can be greatly successful in the pursuit and interception of the second-generation Boeing 737. In addition to the national will, there are also considerable factors in leading platform technology.

After the rise of Airbus' A320, Boeing, which learned from the pain, created the third-generation 737600, 700, 800 and other models, and then it matched the technical level with the A320.

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

Like Airbus' a380, a350, and Boeing's 787 have all reached the fourth stage of composite use, but the a350 and b787 are more extreme.

The mpc75 branch passenger plane will use composite materials on a large area on the wings, vertical tails, hatch doors, etc. to reach 20% of the weight of the aircraft structure. Looking at the words in front of you, Liang Yuan blinked hard.

No wonder this guy pulled a lot and ran far. Liang Yuan pressed Ziji's palm with his nails to confirm that Zijiméiyou's eyes were dazzled.

Liang Yuan, who has seen at least the development history of large passenger aircraft in the next 30 years, knows that in Ziji's memory, as well as the development plans of Airbus and Boeing before 2020, as for the advanced xing of the platform, mpc75 is invincible in the field of medium and short-distance narrow-body passenger aircraft. No wonder the Germans wrote at the beginning that even if we enter the new century, mpc75 passenger aircraft will still be the technical leader of regional passenger aircraft.

Liang Yuan thought about the large-scale verbal battle between France and the Federal Republic of Germany that had lasted for several years and established the second Airbus production line in Hamburg. He thought about the establishment of the BWM/R engine manufacturing company a few days ago. Federal Republic of Germany announced in the newspaper that BMW will cooperate with Rolls-Royce to develop the 6090kn RB700 series turbofan engine.

The German Hans, whose economic strength has soared in the 1980s, could they build the A320 aircraft tail as they did in the current republic? In order to maintain Ziji's leadership in Airbus Group and maintain domestic employment, the Frenchman repeatedly rejected the request for additional production lines in the Federal Republic of Germany.

Think about the news of the merger of Mbb and Mercedes-Benz Aerospace, and the Federal Republic of Germany was indeed a big game of chess.
Chapter completed!