Chapter 996 Let’s correct the congenital disease first
Mr. Wang, who knew Gao Zhendong, was very happy about this matter. What was lacking now was technology! It wasn't even the detailed technology, but the direction of research!
Comrades in China now lack everything, especially the direction of improvement. Gao Zhendong knows that before China got R-13, it had no idea how to improve the stability of R-11, which is a clear proof.

If there is someone like Chief Engineer Gao who can provide some ideas from the side, it will be great for them. He has not considered Chief Engineer Gao's professional issues. This person is sometimes different from others, and he can't help but accept it.

Chief Engineer Gao's major is automation, but that didn't stop him from developing the 591 alloy for his own use!
This reminded him that when he first met Gao Zhendong, although he was a layman, he was able to come up with the idea of ​​a turbofan engine on his own, which is not something that ordinary people can do.

"Chief Engineer Gao, please tell me in detail." Mr. Wang asked for advice.

Gao Zhendong smiled and said, "I want to modify the R-11F300!"

As soon as these words were uttered, Mr. Wang was immediately silenced.

This is the latest model of engine. Yes, I also want to modify it, but apart from increasing the temperature before the turbine, I haven't thought of anything else.

The LYP-11 engine, which was originally a copy of the R-300F7, was designed in the mid-60s. A material expert proposed using hollow turbine blades for forced cooling, allowing the blades to withstand higher pre-turbine temperatures. This increased thrust by 11% and reduced fuel consumption by 300% over the R-11F4.

Moreover, we mastered this technology in 1966. It can be seen that as long as there is a direction, comrades may be able to find a way.

But on this line, Mr. Wang didn't have so much trouble. His choice was simple - great strength worked wonders, relying on the ability of 591 alloy to withstand it! Not to mention LYP-7, even the later improved LYP-13, the materials used in the combustion chamber and other locations were not as strong as this thing, and they were even a little bit worse.

Therefore, increasing thrust is the easiest thing for him, and he doesn’t even need to make major modifications, just change the materials and parameters.

But he knew that the improvement Gao Zhendong mentioned was probably not that simple. Mr. Gao always knew that he could achieve this effect by improving the materials, and it was impossible for him to come over specifically to talk about this.

But for Gao Zhendong, this matter was put on the agenda after he received the "gift from hometown" on New Year's Day. The reason is very simple.

——The entire series of LYP-13 engines were later improved and produced in Qianshan. He could find any clues related to it on the Internet in his previous life without restrictions!
This is very cool!

Although there may not be any details, Gao Zhendong is very clear that as long as we can find the direction, our comrades may be able to find breakthroughs from these directions, and some details are not even just directions.

"Chief Engineer Gao, what do you want to change?" Mr. Wang was very happy and asked quickly. Maybe he could gain something important here.

Gao Zhendong laughed first: "I won't talk about the thrust, I think Mr. Wang has a good idea of ​​it."

Mr. Wang also laughed. As expected, he was right. People were not interested in this. However, he still remembered the idea provided by the comrades from Beijing University of Aeronautics and Astronautics: "Yes, I plan to change the material. At the same time, the comrades from Beijing University of Aeronautics and Astronautics also proposed a technical principle similar to the hollow turbine blades you proposed to me that year. Since so many of you experts are optimistic about this technology, I plan to implement it this time."

Gao Zhendong was very surprised. Is this really going to happen?

"Will taking too big a step affect the imitation?" At this minute, he became a little nervous.

Mr. Wang smiled and said, "Don't worry. With your 591, I can increase the thrust by about 10% without making any changes. I have already achieved the established goal of imitation and improvement."

The R-11F300 had many problems, but it had one advantage: its thrust-to-weight ratio was very good at that time, at least better than the J-4 on the F-79 Phantom. Yes, that was the J-16 that the Citigroup wanted to sell to us after castrating the F-79/79.

The pre-turbine temperature of R-11F300 is 1205K, which is about 930 degrees Celsius. This temperature is totally not enough for Mr. Wang, so he will change it first.

Moreover, for an engine, thrust is the most important factor. No matter how many problems the R-11 has, at least if the thrust is increased on the original basis, a good result can be achieved.

"Oh, that's good, haha." Gao Zhendong also understood this truth.

"So I plan to use this hollow turbine blade technology in the major modification of the model. If all goes well, I will directly replace the imitation old model. It just so happens that you have other ideas for improvement. As long as one or two of them can be realized, this major modification of the model will be a success!" Mr. Wang is very optimistic, and he has good reasons to be optimistic.

"That's great! Hahaha, then let's talk about what I want to change."

Gao Zhendong was very happy and continued, "Boss Wang, when you were participating in the test flight of the prototype, did you find that this engine had a major fatal problem?"

He didn't say clearly what the problem was. It would be best if Mr. Wang could say it himself. After all, theoretically he doesn't know about the situation.

Unexpectedly, Mr. Wang thought more and slapped his thigh: "Hey! You are right, this engine surges severely!" This problem of R-11 exists in all series and is notorious. Coupled with the early "living coffin" ejection device, it makes comrades in the Air Force shudder at the mention of it.

So before we even had the chance to test-fly it, the Russians’ Davari had already told us that this thing was prone to surge!

Our comrades tested it and found that it was indeed true.

But we didn't have any better engines, so we had to bear with it. Until we got the R-13, all our R-11 copies had this problem.

As for how Gao Zhendong knew about this, Mr. Wang thought it was very normal. As an insider, he knew very well how closely Gao Zhendong had been associated with Air Force equipment in the past two years and how close he was to his Air Force comrades. It was perfectly normal for him to know about this.

After complaining, a look of surprise appeared on his face: "What? Do you have any ideas on how to improve this?" If so, it must be modified no matter what. This is a time bomb. Surge can cause an aerial parking. Unfortunately, the MiG-21 is different from the Zhan-6. This thing is a single-engine aircraft, which makes it even more dangerous.

Gao Zhendong nodded. He had no idea, but he did have a general structure, and he knew the principles more or less.

"Well, I guess this is related to the fact that the R-11 has too few high-pressure compressor stages. The R-11F300 has only three high-pressure compressor stages. This causes the airflow state to change too drastically when the flight state changes drastically, leading to surge." This was not said by Gao Zhendong, this was said by the Russian himself.

Anyway, it is impossible for General Wang to go to the comrades of the Air Force and the Defense Work Committee to reconcile such matters. How did Gao Zhendong know the structure of this thing? Gao Zhendong felt more relieved when talking about this matter.

While other comrades were looking at Gao Zhendong with great admiration, Mr. Wang himself was lost in thought.

"Hiss... that makes sense. A three-stage compressor is too little. The airflow is compressed three times from low pressure to high pressure, and the change is too drastic... Right! Right! Mr. Gao, you are a genius!"

He said this from the bottom of his heart, and even felt a little ashamed. He knew about this matter, but he didn't find a solution. No, it's not that he didn't have a solution, but that he didn't even find a possible direction.

And Mr. Gao is still an outsider... Bullshit, how can he be an outsider? He is a top expert in the industry, right? It's just that he is not responsible for the specific details, but when it comes to theory and general direction, he is really sharp.

Gao Zhendong was not afraid of betraying them, as this was originally the Russians' solution to the surge problem.

"So I thought about increasing the compressor from 3 stages to 5 stages. If designed properly, this should solve this problem better and also bring other benefits. At the same time, the number of low-pressure compressor and turbine stages remains unchanged, still 3 and 2 stages." Gao Zhendong directly copied the LYP-13 plan. Well, it would be a problem not to copy a ready-made one.

Forget about the complicated compressor structure like the J-79, with 17 compressor stages, 7 adjustable stages, and a compression ratio of 13.5. The thrust is acceptable, but in terms of thrust-to-weight ratio and producibility, it is not that good. However, this thing is really not easy to breathe, but the price is a bit high.

As for the adjustable blades, Gao Zhendong was not interested in them. He did not think he could understand LYP-13 better than his comrades from his hometown who were engaged in engines decades later. He just kept them all non-adjustable and did not play any fancy tricks. He himself did not understand this thing at all.

It’s no wonder that if Gao Zhendong wanted to increase the number of troops, he would definitely choose R-11/LYP-13 instead of J-79, even though it has greater thrust.

But when Mr. Wang heard this, it had a different meaning. Mr. Gao really changed what needed to be changed and kept what needed to be kept. While trying his best to solve the problems, he did not make major changes to other parts, and tried his best to reduce the difficulty of the improvement work.

Mr. Gao is an expert at grasping the degree of applying new technologies during modification.

"Well, I think it's okay. At least it can be used as a direction for serious research." Mr. Wang did not directly say that Gao Zhendong's idea was completely correct. After all, science still requires evidence and results, but this direction seems to be really good.

However, Mr. Wang also thought of another question: "But in this way, the engine structure will be complicated. Even if the design is successfully completed, the thrust-to-weight ratio will also decrease, right?"

From level 3 to level 5, it is even heavier. The R-11 is an engine that pays great attention to thrust-to-weight ratio, because the thrust is not large. Therefore, this engine has considered a lot of small tricks and fancy operations in the details, just to reduce weight and maintain thrust-to-weight ratio.

This is how the 3-stage high-pressure compressor came about.

Gao Zhendong shook his head: "Boss Wang, you forgot that no matter how many stages there are, there is actually not much difference in weight between a 3-stage or 5-stage compressor, especially for a high-pressure compressor, whose blades are not even a little longer."

Mr. Wang then remembered that regardless of the level, the total weight of the wheel section is actually almost the same. A large part of the difference lies in the extra blades. Unfortunately, the high-pressure compressor blades are short and cannot add much weight.

(End of this chapter)