Wealth

Actually. Just as a technology. The role of the large aircraft project is also wrong.

Assuming that the test aircraft type is successful, localization will definitely bring about a substantial increase in the manufacturing level of domestic enterprises. By that time, the price of imported large aircraft components is estimated to drop by more than 30% after the prototype has flown along the domestic route for a week.

If a large aircraft prototype can fly to America and then fly back, it is estimated that the price of imported large aircraft components will fall by more than half, which means that the import cost will be greatly reduced, which is a very low cost. From this point of view alone, there are also research strategies with great economic benefits.

This speculation is not a silly dream, but a real fact, because at present, large aircraft are inherently an absolute monopoly, and the price is not transparent. Even if it is transparent, the cost of human resources and resources in foreign countries is very high. If it is localized, It is estimated that only one third of the cost of foreign countries can be used to produce large aircraft products, which will definitely cause big aircraft manufacturers such as Boeing and Airbus to be greatly affected.

Of course, it is not foreigners who are most affected, but a group of people from the Civil Aviation Administration of China. As well as the people responsible for the large aircraft procurement plan, although these people are not high-ranking, most of them are at the departmental level, but the country loses a large amount of dollars because it does not have its own large aircraft, basically from these people. Flow out of hand.

As we all know, as long as there is purchase, there must be a rebate, and the percentage of this rebate is quite large.

If we say that there are the most unhappy people now. These are the people.

The leaders who visited the China Aviation Manufacturing Corporation have different thoughts. The leaders of Lingxi Province are naturally more excited. After all, the landing of this large project base in Lingxi will bring considerable benefits to Lingxi Province. The influence of Lingxi's economic development in the future will largely depend on the pull of the large aircraft project.

The cadres and employees of the group company also felt a little emotional. In the past, things that were so difficult to do when the state supported them, now they have been replaced by a private boss, and they can do it so easily, and the effect is not bad. There are big problems with the system. The personal will of the leader often overrides the national interest, which is very abnormal.

If there had long been an open environment like this, it is estimated that China's large aircraft manufacturing technology would have passed the Americans a long time ago.

"It's not too late to catch up, I'm afraid that if you don't advance, you will retreat," said an old engineer who was in charge of leading the tour with some emotion.

Everyone agrees with this, just like the domestic computer technology, which also led the way back then. Hasn't it been dumped to Java? This is the same truth.

Fan Heng, Fan Wubing and others also visited the model area and the 3D animation design effect demonstration.

Large passenger planes need to cruise for a long time at an altitude of 9,000 to 10,000 meters with high sub-tones. Therefore, wings are generally swept back with a large aspect ratio, with a sweep angle of about 35 degrees. In order to improve the efficiency of wings during take-off and landing, large passenger aircraft usually use full-span leading edge **** or slats, and use double-slit or three-slit **** on the trailing edge, and steerable disturbances are also used on the wings. Flow board.

This kind of spoiler has multiple functions, which can assist the ailerons in the roll control of the aircraft, and can also be used as a drag plate when the aircraft is reduced. also. It can also be used as a lifting plate to open when the aircraft is landing at 6 o'clock after the wheels of the aircraft touch the ground, so that the aircraft can land firmly on the runway and prevent the aircraft from rebounding.

Therefore, the auxiliary surface on the wing of a large passenger aircraft. Unlike a small airplane, there are only four yuan (two **** and two ailerons), but fifty yuan. These fifty auxiliary surfaces must be designed to solve the problems of function, structure, manipulation, and vibration. This is a special field in the design of large-scale collectors.

However, these structural features have already been realized in the first large passenger aircraft developed in China, saving a lot of time and energy at this time.

The main feature of the large passenger aircraft fuselage is when flying at high altitudes. The vast majority of the fuselage is a pressure vessel with internal pressure. This determines that the profile of the fuselage is preferably circular, because a container with a circular profile is most beneficial to withstand internal pressure. Sometimes in order to increase the volume of the cabin, a double-circle-shaped figure-eight cross-section is used, so that the upper and lower parts are composed of circles, and the middle is pulled by the cross beam of the floor, which is also ideal in terms of force.

At the rear end of the cabin, the web of the frame bears a lot of outward pressure. If it is designed as a strong flat plate to withstand the pressure, the structure will become very heavy. therefore. The rear end of the passenger cabin is often designed to be spherical because of the situation, so that less material is used and it is conducive to withstand pressure. This requires that the basic section of the fuselage, whether designed in a circular or non-circular shape, should be shrunk to a full circle at the rear end of the cabin to facilitate installation of the spherical frame.

In this way, the doors and windows on the cabin. They all become openings on the pressure vessel.

Therefore, the design of the door frame and window frame should disperse the stress concentration caused by the opening well. Large passenger planes have about a hundred portholes, and they should be designed with a basic and consistent window frame. The door of the passenger cabin must be without threshold. This is for passengers to pass the cabin door smoothly and leave the cabin in the shortest time if the plane is taxiing out of the runway.

On the other hand, the cabin door should be able to safely withstand the pressure in the guest cabin at high altitude, and must not be ejected by the internal pressure like when the cork is opened, so the locking mechanism of the cabin door should be designed to be safe and reliable. In addition, clear signs should be printed inside the door to remind passengers that they must not move the door handles during flight. That's why.

The passenger seats in the cabin are fixed on the slide rails longitudinally framed on the floor beams. Therefore, when the plane is flying in the air, the position of the seat is very fixed, which can withstand the impact of various situations and protect the personal safety of passengers.

But between each flight, if you want to adjust the position of the seat, such as adjusting the size of the first-class cabin, you only need to move the seat on the slide rail. This not only satisfies the needs of various flexible adjustments in the flight room, but also ensures the safety of each flight.

This design has been adopted in the previously developed Yun-10 aircraft in China. In the test flight, the seat arrangement in the cabin and the installation of test instruments were arranged according to different needs during the test flight. This adjustment is actually Very convenient.

In fact, the most critical technology is still motivation technology, which is the key issue for China's large aircraft. Fortunately, it has now been resolved. However, the effect and whether it can withstand the test of a long period of time remains to be further tested.

There are industries that supply power plants in the world. At present, the small Chinese civil aircraft under development, the aircraft of Boeing and Airbus in Europe, are all moving toward manufacturers around the world to purchase incentives to match the aircraft. In fact, according to previous assumptions, when developing a new large passenger aircraft within the company, it will first purchase motives from global motive suppliers.

In the composition of the aviation industry, aircraft models are generally at the top of the pyramid. In today’s open world, many people believe that the exhibition of the domestic aviation industry needs to occupy the commanding heights from top to bottom, and the exhibition of aircraft models will come. Traction drives the overall situation. As for the sub-systems that make up the various parts of the aircraft, the supply can be obtained in a completely special way, instead of laying the foundation stones of the pyramid from the bottom up, and then showing the aircraft model.

Aviation motive is a very complex, very precise, high-speed, high-stress, and high-temperature equipment. Technically, it can be said to be in the best position of contemporary mechanical products.

In the past, when Yunshi was developed, two methods of supplying motives were used in parallel. While developing domestic motives, they also purchased motives from foreign suppliers for use, and compared the effects.

At present, the domestically-made high-power aviation motive developed by China Aviation Manufacturing Corporation. It is the most powerful aviation motive developed in China in recent years. This type of motive has now passed a rigorous test vehicle, and has been installed on an airplane for aerial test flight. The effect is still good, and it is also being continuously tested and improved. Strive to improve day by day, and from it derive various types of special aviation motives.

The developers of www.wuxiamtl.com took into account during the flight test flight of the tenth year that if the aircraft and the motive were newly developed, it would be difficult to determine the cause if some data deviated from normal during the flight test. Therefore, in the early stage of the Yunshi test flight, the motives purchased from the world’s motive suppliers were assembled. As a result, the domestically-made aircraft and the motives were tested separately. The next step should be to use Chinese aircraft to install the domestically-made motives for the test flight, but unfortunately, the Yunshi The project was permanently shelved for no reason, and the test flight was stopped.

During the visit, Fan Wubing also found a problem. In terms of the overall layout of the aircraft, the motives of some large Russian aircraft are very close to the fuselage, but the models of large aircraft projects we have designed by ourselves are different. What are the different considerations?

The chief engineer of the company explained to Fan Wuyao. "President Fan raised this question very well. The Soviet Union's first jet airliner was designed to install the motive on the wing root, which made the structural force transmission design of the motive and the arrangement of the system piping very troublesome, and the maintenance of the motive was very difficult. The problem is that the noise of the engine jet will impact the fuselage. The passengers in the cabin will be annoyed by strong sound waves. What is more serious is that the bulkhead of the pressure cabin will be fatigued due to acoustic shock and accidents. Therefore, this kind of wing root motive layout is in In the early days of jet airliners, in addition to the Soviet Union, some European countries used them, but they were quickly abandoned."

"Oh, that's how it is." Fan Wubing nodded, saying that he was taught.