Chapter 480 Domestic turbofan 9!

The design review of Turbofan 10 was successfully completed, which means that the entire project has officially entered the research and development stage.

At the same time, the technical verification work in production and manufacturing has not stopped.

In the technical room of Factory 410, a group of engineers were standing or sitting around several computers, looking at the 3D models on the CRT monitor screen.

1995年，涡扇9的国产化率达到70%，标志着为期4年的涡扇9发动机材料国产化项目告一段落。

It seemed at the time that the remaining 30% was difficult for Factory 430 to solve on its own in a short period of time.

Fortunately, in the following two years, Hao Jing did not mess up.

In addition to linking the lines of Chang Haonan and 410 Factory through the Seiko Project to become the technical verification model of the turbofan 10, the most important achievement is to digitize the original design of the Spey MK202.

Of course, this is also a request Chang Haonan made at the end of last year.

There are so many design documents related to a type of aero-engine that if they were all presented on paper materials, they would probably fill several filing cabinets.

To transfer this kind of physical data from Haojing to Shengjing is definitely a huge project.

Moreover, loss or defacement will almost inevitably occur during this process, and it will be a mess at that time.

Therefore, Factory 430 spent most of this year moving most of the technical information to computers.

"Hiss... the design of your turbofan 9 seems to be a little different from the previous SPEI MK202..."

An old engineer from the 410 Factory touched his gray temples and said hesitantly.

When Sibei was introduced, the original plan was to localize it in Shengjing. However, at that time, the 410 Factory was working on the turbofan 606 with the 6 Research Institute, and they were worried about being affected, so they did not take the job.

But there are still many technicians who have inspected this model.

This engineer named Yang Qing is one of them.

As the most advanced aero engine that China Aviation Industry had ever come into contact with at that time, some technical details could still be remembered even after more than ten years.

Zhang Zhenhua, the technical director of Factory 430, nodded.

As the person who knows the situation of Turbofan 9 best in the country, he was naturally drawn into the Turbofan 10 project team.

However, so far, most of the work is still done by the old guys:

"Indeed, this version has been modified and some unreasonable parts of the original design have been optimized."

He said and pointed to the screen of a computer in front of him:

"The first one is to change the floating ring sealing device at the high-pressure turbine bearing to a grate sealing device. This is mainly to prevent the lubricating oil at the sealing ring from coking, causing the floating ring to become stuck and unable to move, and ultimately causing the floating ring to become stuck. The gap between the shaft and the shaft forms a gap for oil leakage, and the second one is..."

Although the explanation is clear and logical, it is obviously not very convincing.

"Design modifications..."

Yang Qing showed a worried expression:

"Are you sure...that you've digested everything?"

Although the other people next to him did not directly question it due to their personality or qualifications, judging from their reactions, they probably had similar thoughts.

It’s not that they have any prejudice against Factory 430.

But something similar happened during Sibei’s imitation process——

In the mid-80s, when Factory 430 wanted to convert the ship's gas turbine to a combustion engine, it did not do enough analysis and testing on the original model of the aerodynamic design of the high and low pressure compressors, and ignored the interaction between the flow path of the ship's gas turbine and the aircraft. The difference in engine speed almost caused a major accident.

This wasn't the end of the story. Later, they even started testing the complete machine first, and then the components, which was so cruel that it made people's eyes darken.

As for the result...

Although Sibei Gaifan theoretically completed the appraisal test, the test time of the complete machine from 1990 to 1993 was only about 60 hours, which was really unconvincing. In addition, there were no installation targets, and the localization rate could not increase, so we had to That was settled.

In short, it is reasonable for Factory 410 to be uneasy about these peers.

Zhang Zhenhua scratched his head in embarrassment.

Although he himself was not involved at the time, he must admit that his own unit had indeed done a lot of bad things in this regard in the past.

Fortunately, he had already thought about how to face such doubts:

"These modifications were not made by ourselves. When we came to Shengjing for a meeting at the end of last year, Mr. Chang helped us point them out."

No one answered.

However, Zhang Zhenhua clearly heard a sigh of relief.

neat and tidy.

This explanation is obviously quite convincing.

Of course, we are all serious technicians, and it is impossible to just hear the name Chang Haonan and let it go.

So he spent another ten minutes explaining in detail the reasons for making these improvements.

"So what are the main technical difficulties we need to overcome this time?"

Despite the technological accumulation of the turbojet 14, the research and development of the turbofan 10 is also advancing at a high speed, but just like it takes time for students from 985 universities to go back to do junior high school or even elementary school exam questions, it is necessary to localize the turbofan 9 Increasing the efficiency from 70% to 100% is definitely not an overnight process.

"three aspects."

The speaker this time was Lin Weiguo, the technical director of Factory 410. After Zhong Shihong was promoted to deputy general manager, he was urgently transferred back from Persia to participate in the Taihang project.

“一是把1-7级高压压气机盘、轴、1-8级隔圈和相关传动件的材料更换为国产2Cr10NiMoVNb钢，在组织涡喷14生产的过程中，我们协助钢企完成了对这一材料中δ-铁素体含量的控制。”

"The second is to improve the forging process of low-pressure compressor discs and blades, using hot die forging in the a+β phase zone at 900c."

These two pieces of content are logical and can basically be regarded as the mission settlement rewards after the Turbojet 14 is successfully finalized.

Later, Lin Weiguo took out a picture from his briefcase and clamped it on the drawing board behind him.

“The third step is to replace all four sets of spindle bearings with corresponding domestic models. Fuzhou Bearing Group will be responsible for the production of the bearings themselves, but for us, we need to integrate the bearings and the entire support structure in advance before final assembly. , becoming the same spindle connection component.”

This already belongs to the category of design improvement, and is actually completed by 606.

It's just that the designer over there went to the review meeting today, so he couldn't get away.

So in order to explain the situation easily, he specially printed a drawing and brought it over.

"In this case, if you want to remove the bearing... you have to disassemble the entire engine."

After all, Yang Qing had rich experience and knew Sibei well, so he was the first to see the clues:

"However...it can indeed reduce about 100-120 parts and about 25 kilograms of weight."

It should be said that the Spey MK202 is indeed not a very advanced engine.

Especially for China, which has successfully finalized the Turbojet 14 on this timeline.

Its only advantage may be that its fuel consumption is very low, but that is at the expense of a medium bypass ratio.

According to the national standard, this engine with a thrust of just over 9 tons has a dead weight of 1842kg, which is heavier than the F110 and AL31F.

Considering that even if this old-fashioned core machine is pressed to the limit, the thrust force will hardly exceed the 10-ton mark, so the best way to improve the performance of the domestic model is to increase the weight.

In addition, reducing the number of parts will also help reduce the failure rate.

So this is one of the technological trends of the fourth generation engine.

For example, the number of components of the EJ200 engine is only about 199% of that of the older generation RB65.

The trade-off is that it can be difficult to repair if it breaks down.

"This is a bearing we developed using the latest technology. It is produced according to the standards of the third-generation engine, that is, the turbofan 10. The expected life is not shorter than the first turning cycle of the engine."

Lin Weiguo tapped the drawing board lightly and explained,

“That is to say, under normal circumstances, only the entire component needs to be replaced during the overhaul process, and there is no need for ground crews to disassemble it for maintenance or repair.”

"So...our turbofan 10 will also use this technology?"

Another person asked.

Everyone knows that improving the Turbofan 9 is just a casual step, and these high-end technologies will eventually be implemented in new models.

"General Manager Chang's goal is to control the number of components of the turbofan 10 to less than 2200, while the current turbojet 14 has about 3150 components."

Lin Weiguo’s answer was concise and concise:

"I did some calculations before. If this round of testing passes successfully, the localization rate of Turbofan 9 will probably increase to about 92%."

After all, after the main bearings and high-pressure compressor are all domestically produced, there is basically only the last hard nut left, which is the turbine.

This part will have to wait for a while to verify the domestic third-generation nickel-based single crystal materials.

He put down the pen in his hand, turned around again, and looked at the colleagues in front of him:

"According to the timetable, the nationally produced turbofan 9 will probably be put into complete machine testing in the middle of next year!"