Chapter 512: Finally able to independently produce turbofans!
Although it is just an improved model, aviation safety is extremely important, and the necessary testing procedures must not be sloppy.
What's more, the utilization rate of new technology in this so-called "Spey modification" is almost more than one-third -
The first prototype No. 9A-01 modified the high-pressure air compressor Some unreasonable designs of the machine blades and oil supply parts were replaced with new domestic oil pumps, bearings and gear sets, and the original bearing components were integrated.
This reduces the number of components and widens the surge margin.
By this time, although there were still many modifications, they were still minor repairs to the prototype engine.
Not only the performance calibration has not changed, but the core design of the hot end component has also remained original, so the basic performance has not changed much, except that the weight has been reduced by about 75 kilograms.
But on the second prototype 9A-02, which was produced at the end of 1997, the changes were relatively large.
In order to test the effectiveness of the new active cooling technology, Chang Haonan specifically asked technicians from the 606 Institute to modify the engine performance calibration.
By improving combustion efficiency and upgrading aviation fuel, the temperature in front of the turbine has been increased by about 50-60°C, reaching a level close to that of the third-generation turbofan engine.
The design of aero-engines affects the whole body.
To this end, the compressor of the second prototype engine has also been modified. The blade separation flow active control technology developed during the development of turbofan 10 is used on the 9-12 stage high-pressure compressor blades. Increase the total pressure ratio of the compressor to about 22-23.
However, since the research and development of the manufacturing process will take time, the electrolytic machining, electron beam welding, precision forging, precision casting and other technologies used in the production of this engine are still at the previous level. superior.
Especially the processing of air film holes on the inner walls of turbines and combustion chambers.
Compared with dozens of accurate round holes, the dustpan-shaped hole with forward inclination developed by Chang Haonan is quite unfriendly to the EDM technology developed by 410 Factory.
Not only does the processing of each hole require several more steps than the turbojet 14, but the subsequent grinding and quality inspection also require additional steps.
The yield rate is still much lower.
In short, although Chang Haonan could not wait to start testing this engine that uses a lot of turbofan 10 technology the day after posting the picture, the 410 Factory even if it specially frees up a production line, it will be available three times a day 24 hours a day. Production was carried out in shifts, and it still took more than two months to produce machine No. 9A-02.
......
At the entrance of the engine assembly workshop of the 410 Factory, Chang Haonan, Zhong Shihong, and Zhang Zhenhua stood side by side, watching the engine that had finally completed the factory's complete machine inspection being slowly installed. On top of the specially designed engine bracket.
Zhang Zhenhua deliberately took two steps forward, reached out and patted the tail nozzle of the engine twice in mid-air.
Shengjing, mid-January morning.
The temperature is about minus 20℃.
The metal tail nozzle was bone-chilling, freezing Zhang Zhenhua, who was not mentally prepared.
However, he still couldn't hold it back and gently stroked the fuel oil pipeline exposed on the outside of the engine casing.
Shen Zui's expression is slightly abnormal.
It was not until the engine was fixed by the hoisting team and started to be packed in cargo boxes that he reluctantly returned.
"Sibei, after more than 20 years of domestic production, we have finally created a 100% domestic engine..."
With bursts of white appearing in front of us, Fog, Zhang Zhenhua said with emotion.
In order to speed up production, about a quarter of the components of the previous 9A-01 machine were directly assembled using parts imported from the UK.
But for this second prototype, due to the huge improvements in all aspects, the original British parts could no longer adapt to its working condition.
Therefore, all components are newly produced domestically.
During this process, Factory 410 also verified the application of several key new manufacturing technologies such as metal spraying, vacuum heat treatment, trajectory welding, vacuum brazing, and CNC bending, laying the foundation for the next step in the manufacturing of turbofan 10 The foundation was laid.
"Yes, but it's a pity it's a little too late..."
Zhong Shihong took out a ballpoint pen and signed his name on the factory order and responded:
"After the introduction of Sibei, there was a period of vacillation for more than ten years. Now that domestic models are produced, even if the performance is better than the original product, the prospects are relatively limited..."
The introduction of Sibei , there is also a love-hate relationship hidden between Factory 410 and Factory 430.
The former insisted on continuing to develop turbofan 6, while the latter believed that it should start with Spey.
If I have to say it, it was a lose-lose situation in the end.
As of now, it is no longer clear who is who.
Fortunately, for people of Zhong Shihong and Zhang Zhenhua's generation, they don't have many related memories. The smell of gunpowder between the two units has gradually disappeared with the advancement of the turbofan 10 project and the deepening of R&D collaboration.
Contradictions fundamentally come from competition in resource allocation.
Now that Chang Haonan has almost increased the scale of China's aerospace industry by an order of magnitude, the difficulty of dividing the cake has naturally been reduced a lot.
Nevertheless, after noticing that the topic between the two people was gradually moving closer to the past, he quickly changed the subject:
"It's useless to talk about the past."
While speaking, Chang Haonan also took the pen from Zhong Shihong and signed his name.
The production of the Turbofan 9A prototype is nominally a technical verification machine for the Turbofan 10, so naturally the signature of his chief designer is indispensable.
“No matter what, the demand for the improved JH-7 must be tens or hundreds, and the turbofan 9A can still make a difference in this regard.”
“ It's just a pity that Spey Air changed to combustion. Now the QC130, which has been converted from turbojet 14 to combustion, has entered the design finalization stage. The Navy should not accept another gas turbine with similar power..."
After the factory procedures were signed, the staff quickly loaded the neatly packed engine packaging box onto a special Mercedes-Benz semi-trailer.
This car may be the only 100% original imported product in the entire Turbofan 10 project.
The main reason is that everyone is really busy and has no time to build a special engine transport vehicle.
The produced engine will be transported by this vehicle to Beiling Airport, and then transported by an IL-76 transport aircraft to 624 for necessary ground testing.
“Mr. Chang, what do you think the actual performance of this engine can be?”
As the director of the production department, Zhang Zhenhua has little experience in the field of engine design, so he does not know the specific effects of these upgrades on the Turbofan 9A.
“Don’t have too high expectations...”
Chang Haonan shook his head, returned the pen in his hand to Zhong Shihong, and continued to explain:
“Sibei, this The design level of the engine itself is not good. I spent a lot of time adjusting the data of the compressor and combustion chamber, but the matching is always average.”
“After all, it is an improved model, and it is impossible to go to a lot of trouble to redesign it. Once a core machine comes out, we can only make do with it.”
There was some dissatisfaction with the British in his words.
Of course, the two people next to me would not have any objections.
After all, Mr. Chang’s ability is obvious to all, and he is indeed qualified to comment like this.
“In addition, because at the time of blade production, the multi-arc ion plating equipment in the factory was not yet in place, so the hot-end components had not yet used the new coating technology, and the increase in temperature in front of the turbine was relatively limited. "
"Of course, on the other hand, the temperature in front of the turbine of Spey MK202 itself is already not low. It is true that the British can use such a high temperature in front of the turbine to design such an engine with mediocre performance. ...Tsk tsk tsk ”
At this time, it would be difficult for Zhang Zhenhua and Zhong Shihong to answer the phone.
"Then...how much can some typical paper performance be improved?"
"For more specific details, we will only know after bench testing."
At this time, a Jetta King stopped in front of the three people.
The one driving the car is naturally Zhu Yadan.
Chang Haonan opened the right rear door, turned back to the two people and continued:
"However, according to the performance calibration I did, the sea level thrust can be increased to about 10,000kg. The total weight of the engine, according to the national standard, should It won’t be higher than 1750kg.”
After finishing speaking, he got into the car and signaled that the team could set off.
Only two people were left messy in the wind.
“This is called ‘Don’t have high expectations’?”
Zhang Zhenhua looked at Zhong Shihong next to him with a somewhat stiff movement.
You must know that the sea level afterburning thrust of the Spey MK202 is 9300kg, the national standard dead weight is as high as 1842kg, and the thrust-to-weight ratio is only 5.05.
The turbofan 9A directly increases the thrust-to-weight ratio of the engine by nearly 15%!
“You know, Mr. Chang has always had very high requirements for projects.”
Zhong Shihong held up the cotton hat on his head.
He actually felt it was a bit outrageous, but in front of Zhang Zhenhua, he still maintained his demeanor and did not show any obvious surprise:
"In short, I have begun to look forward to the performance of the Turbofan 10..."< br>
(End of this chapter)