When the leaders came in, the atmosphere became more solemn.

Chief Master Gu sat in the middle, and the meeting officially began.

Chief Engineer Gu looked solemn and said: "Comrades, today is the first time we have a special meeting to discuss the design of the J-8 II model's air inlet. The several design plans we have currently made must be selected as soon as possible.

Carry out detailed design. According to the requirements of our superiors, we must complete the J-8I before the middle of next year.

I think everyone is well aware of the detailed design work of the I model and the issue of all drawings. So in order not to waste everyone's time, today's meeting agenda is only half a day. Now I invite Comrade Wang Ming, deputy chief designer of the power system.

, make a brief introduction, and let everyone fully discuss it!"

The inlet system is one of the major systems of a fighter jet and is a subsystem under the power system. It is a very important subsystem because the matching of the inlet and the engine is very important and affects the flight performance of the entire aircraft. If

If the intake duct is not designed well, many performances will not be achieved, and some intake ducts may even have problems, which may cause the engine to stop mid-air.

Wang Ming is a middle-aged man in his forties. He is now the deputy chief designer of the power system and is responsible for the design of the intake subsystem.

Wang Ming began to introduce several design plans. At the same time, Li Shuguang was also thinking about whether the air inlet design of the J-8 II fighter jet could be optimized?

In his previous life, the inlet used by the J-8 II fighter mainly drew on the inlet design of the MiG-23 and F4 Phantom fighter jets, which indeed met the flight speed requirements of Mach 2.2.

However, in the selection process of the intake duct, the general office and the chief engineer are actually still biased towards conservative, but the young designers in the intake duct design team are more inclined to be advanced.

After all, for the chief engineer and the overall team, if they fail or the progress is delayed, whose responsibility is it?

After all, the design of the Mach 2 supersonic inlet is very complicated and requires wind tunnel testing. It is not just a drawing and done.

Although the Qiang 5 attack aircraft was the first in China to have air intakes on both sides, and it was also a supersonic air inlet, the maximum flight speed of the Qiang 5 was only a few degrees, not even Mach 1.2, and only the J-8 II

half.

Because above Mach 1.5, the design of the inlet becomes complicated. At this time, the supersonic shock wave comes, so the designer must make good use of the shock wave. The binary air intake in the inlets on both sides is relatively

Simple, but wave system design is difficult.

In order for the airflow to generate two oblique shock waves, the two shock waves must intersect exactly at the outer lip of the inlet. Therefore, the oblique plate at the entrance of the inlet needs to be adjusted at any time. This adjustment parameter can only

It was tested in a wind tunnel. There is no way to copy it directly. If you can copy it, you can just copy the shape of the air inlet of the MiG-23, but in fact this won't work.

These parameters are highly confidential and cannot be leaked abroad.

Although China obtained the wreckage of an invading US-made F4 fighter jet in the 1960s and obtained the shape parameters of its air intake, it was impossible to obtain the parameters of the air intake adjustment mechanism.

Otherwise, it would be impossible for the J-8I to use the nose air intake design.

The MiG-23 fighter jet we obtained a few years ago is the same, and we can only map the shape of its air intake.

The wind tunnel test of the intake duct is very complicated, and the biggest change of the J-8 II this time is the intake duct. The aerodynamic shape has not changed much, and the engine has not changed much. It is still the turbojet 13 series, but some have been added.

.

It would be great if there was a reliable computer intake design software, Li Shuguang couldn't help but think.

But now, where can I get this kind of software?

In terms of computer-aided design of aircraft, China's aviation industry is also very backward. In Li Shuguang's memory, the first model to use computer-aided design was the J-H-7. At the end of 1986, the 603rd Institute successfully developed the 7760CAD/CAMM computer-aided design

,Manufacturing and management system.

Of course, compared with France's Dassault CATIA system, this system still has many shortcomings.

The project that truly realizes computer digital design and manufacturing is the J-10 fighter jet. However, the J-10 fighter jet has not yet been successfully selected. It is still early.

If Shen Fei could now introduce Dassault's CATIA system, wouldn't it be able to use it to optimize the design of the J-8 II's air inlet?

Of course, it would be better if we could make domestic design software based on the CATIA system.

One of the key reasons why Shenyang Aircraft Corporation has gradually become inferior to Chengdu Aircraft Corporation is that Chengdu Aircraft Corporation has taken the lead in computer-aided design and manufacturing and introduced Dassault Systèmes.

Although Shenyang Aircraft Company has also been looking for foreign cooperation relationships, such as the J-8 IIACT fly-by-wire flight control test aircraft, Shenyang Aircraft Company has found cooperation with the German MBB company.

You must know that the fly-by-wire flight control system is much more advanced than the mechanical transmission system used by the J-8 II.

The mechanical control system used by the second-generation aircraft is to pull the wire rope to control the rotation of the rudder, but the fly-by-wire control system is different. It directly sends signals to each motor on the rudder for precise control, eliminating the need to go from the control stick to the rudder.

Due to the complex mechanical structure between the two motors, the flight quality is completely different.

This is like the difference between the electronic gear lever used in a car plus an automatic transmission, and a manual mechanical transmission.

In terms of the fly-by-wire flight control system, Chengdu Aircraft chose Dassault to cooperate, and it was very smooth.

As for the Shenfei J-8 ACT test aircraft, due to serious and fatal logic flaws in the control law software and the lack of angle of attack and overload feedback in the pitch attitude control, a serious crash occurred during a test flight, which even affected the

The fate of the heavily revised J-8 III model.

Li Shuguang thought a lot. At this time, the discussion had begun enthusiastically, and many designers expressed their views and opinions.

Seeing that the time was almost up, Li Shuguang also took the opportunity to stand up and said: "I want to express my opinion!"

Chief Master Gu nodded and said: "Okay, you say it!"

Li Shuguang said with confidence: "Chief Commander Gu, leaders and comrades, I wonder if we should start from a longer-term perspective and introduce a computer-aided design and manufacturing system to design the inlet of the J-8 II fighter and even the design of the entire aircraft.

What about manufacturing and escorting?"

When Li Shuguang said these words, the entire audience fell silent. Everyone looked at him as if they were looking at an alien.

How is this possible? Even if it is possible to introduce foreign computer-aided design systems, it will not be possible in a while, and we will not be able to catch up.

I will post pictures next year.
Chapter completed!