The design review of the turbofan 10 was successfully completed, which means that the whole project has officially entered the research and development process.

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

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

In 1995, the localization rate of turbofan 9 reached 70%, marking the end of the four-year turbofan 9 engine material localization project.

At that time, it seemed that the remaining 30% was difficult for the 430 factory to solve by itself in a short period of time.

Fortunately, in the following two years, Ho Kyung did not mess up.

In addition to connecting Chang Haonan and the 410 factory through the Seiko plan to become the technical verification model of the turbofan 10, the main achievement is to digitize the original design of Spey MK202.

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

The design documents related to the Type 1 aero engine are so vast that if they were all presented on paper, they would probably fill several filing cabinets.

To transfer the physical data of this volume from Hojing to Shengjing is definitely a huge project.

And in the process, it is almost inevitable that there will be loss or defacement, and then it will be a mess.

Therefore, the 430 factory spent more than half a year this year to move most of the technical data to the computer.

"Shhh...... The design of your turbofan 9 seems to be a little different from the previous Spey MK202......"

An old engineer of Factory 410 touched his white sideburns and said with a little hesitation.

When Spey was introduced, the original plan was to be localized on Shengjing's side, but at that time, the 410 factory was working on turbofan 6 with the 606 institute, and they were worried about being affected, so they didn't take this job.

But there are still quite a few technicians who have inspected this model.

This engineer named Yang Qing is one of them.

As the most advanced aero engine that Huaxia Aviation Industry had been exposed to at that time, some technical details can still be remembered even after more than ten years.

Zhang Zhenhua, director of the technical department of the 430 factory, nodded.

As the person who knows the turbofan 9 best in the country, he was naturally pulled into the turbofan 10 project team.

It's just that, so far, most of the work has been done by old guys:

"It's true that this version has been modified to optimize some of the unreasonable parts of the original design."

He said as he stretched out his hand to the screen of a computer in front of him:

"The first is to change the floating ring sealing device at the high-pressure turbine bearing to the grate sealing device, mainly to prevent the lubricating oil coking at the sealing ring, resulting in the floating ring being stuck and unable to move, and finally causing the floating ring to grind with the shaft to form an oil leakage gap, and the second is ......"

Although the explanation is the Tao, it is obviously not very convincing.

Design Modification ......

Yang Qing showed a somewhat apprehensive expression:

"Are you sure...... Digested thoroughly? ”

Although the other people next to him did not directly question it because of their personality or qualifications, judging from their reactions, they should have similar ideas.

It's really not that they have any prejudice against the 430 factory.

It's that something similar happened in the process of Spey's imitation -

In the mid-80s, when the 430 factory wanted to carry out the refueling of Spey Airlines, it did not do enough analysis and test work on the original model because of the aerodynamic design of the high and low air compressors, and ignored the difference between the marine gas turbine and the aviation engine on the flow path, resulting in a major accident.

This is not the end, and later it was even more difficult to make people look black after the whole machine test and then the component test.

As for the results......

Although the test run was theoretically completed, the test time of the whole machine from 1990 to 1993 was only about 60 hours, which was really not convincing.

In short, the 410 factory is not very relieved about these peers, and it is reasonable.

Zhang Zhenhua scratched his head a little embarrassed.

Although he himself did not participate at the time, he must admit that his own unit did have a lot of bad deeds in this regard in the past.

Fortunately, he had already figured out how to face such doubts:

"These revisions were not made by ourselves, but were pointed out by Mr. Chang when we came to Shengjing for a meeting at the end of last year."

No one answered.

However, Zhang Zhenhua obviously heard a relieved voice.

Uniform.

This explanation is obviously quite convincing.

Of course, everyone is a serious technician, and it is impossible to pass by just hearing Chang Haonan's name.

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

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

Although with the accumulation of turbojet 14 technology, the research and development of turbofan 10 is also advancing at a high speed, but just as it takes time for students from 985 University to go back to do junior high school and even elementary school test questions, it is definitely not an overnight process to increase the localization rate of turbofan 9 from 70% to 100%.

"Three aspects."

This time it was Lin Weiguo, the head of the technical department of the 410 factory, who was urgently transferred back from Persia to participate in the Taihang project after Zhong Shihong was promoted to deputy general manager.

"One is to replace the materials of the 1-7 high-pressure compressor disc, shaft, 1-8 spacer ring and related transmission parts with domestic 2Cr10NiMoVNb steel, and in the process of organizing the production of turbojet 14, we assisted the steel enterprises to complete the control of the δ-ferrite content in this material."

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

These two contents are logical, and can basically be regarded as the task settlement reward after the Turbojet 14 is successfully finalized.

Then, Lin Weiguo took out a drawing from his briefcase and clipped it to the drawing board behind him.

"Third, it is to replace all four sets of spindle bearings with the corresponding domestic models, and Fuzhou Bearing Group will be responsible for the production of the bearings themselves, but for us, it is necessary to integrate the bearings and the entire support structure in advance before the final assembly to become the same spindle connection assembly."

This is already in the category of design improvement, but it is actually completed by 606.

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

So just to make it easier to illustrate the situation, he specially printed a drawing and brought it over.

"In that case, you have to remove the bearings...... You have to take the whole engine apart. ”

After all, Yang Qing is experienced and knows Spey well, so he first saw the clues:

"But...... It can indeed reduce about 100-120 parts, and the weight is about 25 kilograms. ”

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

Especially for Huaxia, which has successfully landed the finalized turbojet 14 on this timeline.

Its only advantage may be that it consumes fuel, but that comes at the cost of a medium bypass ratio.

According to the national standard, this engine with a thrust of more than 9 tons weighs up to 1842kg, which is heavier than the F110 and AL31F.

Considering that even if this old-fashioned core machine is pressed to the limit, it is difficult for the thrust to break through the 10-ton mark, so if you want to improve the performance of the domestic model, the best way is to pick the weight.

In addition, the reduction in the number of parts also contributes to the reduction of the failure rate.

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

For example, the number of components in the EJ200 engine is only about 65% of that of the old-timer RB199.

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

"This is a bearing that we have developed with the latest technology, and it is produced according to the standard of the third generation engine, that is, the turbofan 10, and the life expectancy is not less than the first turn cycle of the engine."

Lin Weiguo tapped the drawing board lightly and explained,

"This means that, under normal circumstances, only the entire component needs to be replaced during the overhaul, without the need for ground crews to disassemble for maintenance or repair."

"So...... Our turbofan 10 will also use this technology? ”

The other asked.

Everyone knows that improving the Turbofan 9 is just a matter of course, and these high-end technologies will definitely be implemented in the new model eventually.

"Chang's goal is to control the number of components in the turbofan 10 to less than 2,200, while the current turbojet 14 is about 3,150."

Lin Weiguo's answer was concise and to the point:

"I calculated before, if this round of testing is successfully passed, then the localization rate of turbofan 9 can probably be increased to about 92%."

After all, after the main bearing and high-pressure compressor are all localized, there is basically only the last hard bone, that 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 group of colleagues in front of him:

"According to the schedule, the domestically produced turbofan 9 will probably be put into full testing in the middle of next year!"

(End of chapter)