Chapter 109 Choice
In the control room, the few people who saw the results for the first time looked at each other.
Air film hole cooling is a well-established black technology in this era. Foreign countries have blocked this technology so tightly that in the past ten years, only one paper in the related field has been published in the world - also This is the article that originally proposed the concept of film cooling.
According to basic physical principles, the size, distribution, and most importantly, the shape of the pores in the air film will affect the heat dissipation effect. However, China in the late 80s undoubtedly did not have the ability to conduct in-depth research.
Similar to the flutter active control method proposed by Chang Haonan that was hidden by the 603, the specific design method of the turbine blade air film hole is also unknown to companies such as Rolls-Royce, General Motors, Pratt & Whitney or Leurica-Saturn. secret.
If you want to learn from it, you can't find any way.
Therefore, Yan Zhongcheng and others chose a very conservative round hole design when designing turbine blades.
The cooling effect can only be said to be unsatisfactory. Fortunately, the temperature in front of the turbine of the Turbojet 14 is not too high. The point is that the design process is relatively simple and there will be no mistakes.
Moreover, if it is a design flaw brought out from the mother's womb, its performance will be relatively stable, but to a very poor degree.
But this is not the case.
So the problem lies in the manufacturing of the turbine blades.
Or to be more precise, it should be during the process of air film hole processing.
The separation system of factories and offices commonly used in aviation systems does ensure that resources are concentrated in their respective key directions under the background of relatively difficult conditions. However, the loosely coupled collaboration method between the design office and the main engine factory determines that there is essentially no communication between the two parties. of mutual affiliation.
Although Factory 410 needs to cooperate with the work of Institute 606, it does not obey the management of the latter.
The people who came to Fucheng with Yan Zhongcheng this time were all engineers from the 606 Institute. They generally knew little about the manufacturing process, and they were immediately troubled by this problem.
The chief engineer responsibility system was established a few years ago to a large extent to solve this problem, and it has shown good results from the subsequent situation. However, the August 80rd Project and the Kunlun Engine, which were already established in the mid-s, did not have such a team. .
After all, it is rare to be able to lead the overall situation as the chief designer like Yang Fenghata.
Not only does one need to have sufficient prestige, but more importantly, the superior must be willing to provide support later.
"Xiao Chang, I remember that you should have visited the 410 Factory before coming to Fucheng this time. Did you find any problems? I mainly mean... the management level?"
After a while, Yan Zhongcheng asked.
Of course, he often goes to the 410 factory, but as a model chief engineer and a "brother unit leader" his goal is too big, so even if he goes there, he may not be able to see anything.
Chang Haonan shook his head:
"For the two newly assembled engines, only the casing and compressor parts are newly made. The combustion chamber and turbine at the back are all previously produced parts. At least from the perspective of the production and assembly process of the compressor blades, it can be calculated It’s very well organized.”
He suddenly remembered the pile of blades piled in the scrap area of the workshop.
That afternoon in the restaurant of the production workshop, Zhong Shihong once explained in detail the manufacturing and testing standards of compressor blades.
Although I can’t remember the specific data, the other party said that these standards were determined after nearly 30 years of exploration.
So he opened his mouth and added:
"Air film hole manufacturing is completely new to our aviation manufacturing field in China. I think it is possible that they have overlooked some key points."
The atmosphere fell into silence again.
In theory, this is not a fatal flaw.
However, everyone here just experienced such an uplifting experience yesterday, a joy of finally turning into a serf and singing.
A second-generation engine has a performance that is close to that of a third-generation turbofan.
The Turbojet 14 in front of us is the treasure in everyone’s heart at the moment in 606.
Even if there is only one ten thousandth chance that something will go wrong, everyone wants to eliminate possible hidden dangers.
Once bitten, twice shy.
Turbojet 14 has experienced too many ups and downs.
It would be fine if they were always in darkness, but now they have seen the light of hope.
No one wants to lose it again.
"Perhaps, we can ask Factory 410 to send the No. 02 prototype that has been finalized for testing. Maybe it is an isolated case?"
Someone finally spoke up and suggested.
"You can also try replacing a new high-pressure turbine?"
"..."
Listening to the increasingly noisy discussions around him, Chang Haonan suddenly realized a problem.
It seems that everyone's focus has gone astray.
The person who initially wanted to find the cause of the engine's unstable working condition was indeed himself.
But now the people around them seem to be more persistent in eliminating hidden dangers.
Well... maybe even paranoia, or fanaticism.
A bit similar to Yao Mengna from the previous period.
But this time it is really possible that the progress will be delayed.
In fact, Chang Haonan was most worried about some unknown structural defects in the engine.
If that's the case, simply improving the surge margin to treat the symptoms will definitely not work.
Therefore, after truly identifying the problem, he himself breathed a sigh of relief.
First, it has been proven that this problem is not fatal, and second, subsequent production improvements will not affect the design finalization task.
If conditions permit, he is of course willing to continue digging deeper to satisfy his inner perfectionism as a scientific researcher.
However, engineering things are never perfect and must be considered comprehensively based on the actual situation.
Even the rockets used for manned spaceflight can only achieve 99.8% overall reliability instead of 100%.
Risks are not scary, only when risks are out of control are scary.
Moreover, for the turbojet 14, a power that can be used on the two main fighters, the J-7 and J-8, delay in progress is itself a risk.
The choice between soundness and efficiency is like walking a tightrope.
The layer of paper between being bold and promising and being blind and reckless was finally placed in front of Chang Haonan.
Perhaps even he himself has not realized that he has unconsciously begun to think about issues from the perspective of overall project management.
……
"It seems more appropriate to let Yan Zhongcheng come forward to talk about this matter?"
Looking at the people who were having a heated discussion, Chang Haonan hesitated again.
If it had been left to the past, he would probably have made such a decision eventually.
But this time, something different seemed to be urging him in his mind.
"Comrades, the high-altitude platform test cannot be interrupted and should continue as planned."
Chang Haonan stood up almost without any control of his mind and said these words.
So much so that he first heard a familiar voice and then realized that it was him who had spoken.
Everyone in the control room looked at Chang Haonan, the only one standing.
Including Yao Mengna.
