The country wants to carry out economic construction, the army must be patient, and the current army is also being reformed, and many armed forces are also short of military spending, and the investment in scientific research is even less.

The limited funds of the Air Force are mainly placed in Shenyang, after all, the J-8 project is about to come out, this is a time to be strong, the Air Force fully supports Shenyang, and the funds of the 611 Institute are naturally very small.

If they had directly mapped and mapped the MiG-21MF, it would have been completed quickly, but now, Song Lao has to go through the process.

For aircraft design, we must take our own innovative road, can not stay in imitation, must be carried out in accordance with our own design procedures, it is strictly forbidden to copy and copy, and the data is not allowed to be used without their own design coordination.

In the eyes of Song Lao, blindly copying once, the design team will be scrapped, and it is unable to deal with the design and technical problems in the process of development and use of the aircraft, and is unable to solve the problem, the only way is to shirk responsibility.

But in this way, of course, it will exceed the budget, the Air Force has no extra funds to provide, and they even have to figure out their own way, but fortunately, there is a capable person like Zhang Lijun who actually came up with a way to sell lunch boxes.

has the face of Song Lao, and those who manage the city are embarrassed to care about them.

More than one million, to the outside world, seems to be an astronomical amount, but, in the study of aircraft, this money, nothing is enough, an aircraft, the cost is millions, they don't even have the money to buy drawing paper, if you don't figure it out yourself, what else can you do?

General Lin over there also sighed: "After I go back, I will urge my superiors to try to allocate more funds to you, but I also have to remind you that the Air Force has been waiting impatiently for a long time, when will our planes be built?" ”

At this time, Song Lao had already taken off his apron and gave it to General Lin, with a wry smile on his face: "We are waiting for the engine." ”

This stall selling lunch boxes is not far from 611, so we didn't get on the bus, and everyone walked in.

The engine equipped with the J-7 is the turbojet-7, and the J-7III aircraft, the imitation of the MiG-21MF, has a different engine, and this imitation is called the turbojet-13.

It is said that an ordinary turbojet engine, or a modification of the turbojet-7, is nothing, but the imitation of this engine can be regarded as a long time.

This engine, first of all, is for the J-7III, and secondly, for the improvement of the J-8, after all, now the J-8 uses two turbojet seven, and the power is not very strong.

To put it simply, the turbojet 13 mainly improves the design of the compressor on the basis of the turbojet 7, increases the air flow rate, and expands the stable working margin of the engine. Moreover, titanium alloy is applied to the compressor parts to reduce the weight of the engine; The structure of each component and system has also been improved, which greatly improves the reliability, durability and handling flexibility of the engine.

However, just like the Turbofan VI, this aircraft was only a modified version, it wasted a long time, and it was plagued by reliability, even if it was finalized in 1987, in fact, the problems continued, and it was only in the nineties that it was generally reliable.

There was once a batch of J-8 equipped with turbojet-13 engines, but after equipping the troops, there were continuous failures, and finally they were forced to change back to turbojet-7.

Now, the research and development of J-7III, in fact, has come to an end, the main thing is the research of processing technology, etc., however, this engine is really anxious to wait, without the engine, this aircraft can not be tested, there is no test flight, there is no legal type.

The 611 Institute will not be engaged in engines, and the imitation task of the corresponding engine is handed over to Liyang Company.

Wait for the engine, it can't be helped.

As he spoke, he walked back to the office, and Song Lao took out a lot of information and began to report to General Lin.

As an all-weather fighter, it is different from the current J-7, and at the same time, although it has become bloated, it can even improve its performance in a certain way.

Like, this blow-off flap.

"In order to improve the landing performance of the aircraft, we added blowing flaps to the wings. Blowing flaps can effectively reduce the landing speed of the aircraft, shorten the landing run distance of the aircraft by up to 35%, and the lifting effect is significant. Song Lao said: "Our Jian-7 has a fast landing speed and is not easy to control, in this way, the landing speed can be reduced." Improve reliability. ”

Blowing flaps, which was popular in the past for some time, is that when the trailing edge flap is opened downward, high-pressure air is drawn from the engine by the nozzle, and the air is blown along the upper surface of the flap from the slit of the trailing edge of the wing, and the high-speed air flow increases the speed of air flow on the upper surface of the flap and replenishes the energy of the attached surface layer on the upper surface. And through the large deflection angle, the balance of centripetal force and pressure difference maintains the attached flow, which delays and delays the separation of the air flow, thereby increasing the maximum lift coefficient.

"But that adds to the complexity, right?" Qin Feng asked.

Song Lao nodded: "That's right, this is the first time we have engaged in this kind of structure, so there are a lot of problems now." ”

Like the variable sweep wing, it sounds great, but when it is implemented, it is offset by the added complexity that comes from the compressor of the turbojet-13 engine, which requires a longer pipe line in the wing, so the structure is more complex.

At the same time, the operation is not easy.

Moreover, the manufacturing process is also complex, as the first kind of high-efficiency lifting device with surface layer control in domestic practical application, the first time to use a riveted full-size honeycomb glued structure, the flap sandwich is a non-porous aluminum alloy honeycomb structure, the outer panel is a chemically milled aluminum alloy skin, and J-30 adhesive is used to glue it together to form a whole.

Recently, the institute has been working on this gluing process.

In fact, this design in later generations, has been verified as a failure, except for this type of aircraft adopted, nothing else, the later J-7 used the leading edge of the maneuvering flap, which greatly improved the maneuverability, and the structure is very simple.

Now, Song Lao's idea is to understand the technology of the MiG-21MF, so he attaches great importance to it, and now that the project of the new Jelf is at a standstill, they only have this one project to do.

"Old Song, come on, you must buy time." After listening to Song Lao's introduction, General Lin did not say anything else, but continued to encourage him like this, and there were many meanings in this sentence.

The Air Force is still inspecting the purchase of fighters, and if it is really decided, many unfinished projects in China will have to be cut to save money!

1 second to remember Aishang:. m.