Chapter 596: Matching of engine speeds between Turbofan 10 and J-10
Europeans, especially Southern Europeans, naturally cannot have high expectations for their work efficiency.
Although for the leader Pierre, the current situation of the NH90 project is close to imminent, so his subjective initiative is full, and he can't wait to drag Wang Xibo with him every day without sleep.
But other technical staff under him did not have this sense of urgency.
After all, even if the sky falls, there will be someone tall to support it, and it has little to do with the workers below.
As a long-established power in Western Europe, the last time France faced the danger of national subjugation and annihilation was 50 years ago. Now it does not have the same sense of urgency that the Chinese people face in this era.
For most people, the Cold War is over, can’t I still enjoy it?
On the other hand, Wang Xibo flew thousands of miles from Ice City to Marseille not specifically to serve Pierre.
As the director of the research office responsible for avionics design of Bingcheng Aircraft Industry Group, his main focus must still be on learning the fly-by-wire flight control technology of NH90.
Helping Pierre and the others digest and absorb the design plan brought by China can only be regarded as a normal performance of the contract.
Therefore, after receiving this new batch of technical information, the NH90 project is indeed advancing faster than before.
But not much.
It will probably take several months to build a new transmission system and then install it on one of the prototypes.
While Wang Xibo was leading the team to carry out work in France, Chang Haonan had also ended his short vacation and returned to Shengjing.
Although the component-level testing of the turbofan 10 was relatively smooth, it was still a key node of the project. As the chief designer, it was not easy for him to be the hands-off boss all the time.
Especially the fan and high-pressure compressor parts also involve the verification of his idea of using blade separation flow active control technology to accurately utilize the vortex structure within the diffuser cascade.
"After all, it has to be Mr. Chang. The difference between the actual experimental results and the theoretical value of the design plan is only 3.6‰, less than 5‰. It is simply..."
"It's simply a divine calculation..."
A dozen core members responsible for the overall design of the turbofan 10 and the compressor part were standing in front of the compressor test bench, looking at the results that had just been sorted out by the operators. Report.
Hai Yide looked at the boost ratio of 25.16 in the results column, with a tone of half admiration and half disbelief.
When determining the design specifications of the turbofan 10, Chang Haonan set the total boost ratio within the range of 25-25.5 to ensure that both installation targets can achieve a good balance between subsonic and supersonic performance. balance.
But normally, there will be some differences between the location of the design point and the actual product.
It often takes several or even a dozen iterative adjustments to truly achieve the desired performance.
During the previous theoretical calculation and design stages, Haiyide had also thought about whether, with Chang Haonan's extraordinary level, it would be possible to reduce the time required for this process, or even achieve it.
But I have thought about it and thought about it.
When the miracle actually happened before his eyes, he still couldn't help but feel a sense of unreality.
Chang Haonan naturally also saw this gratifying result, which means that the time spent in the component-level testing process can be further shortened.
“Such a good result...can’t be entirely attributed to me.”
Hearing Hai Yide’s words of praise that were a little unflattering, Chang Haonan looked away from the hand in his hand. The report was redirected to the compressor on the test stand, and he answered.
Actually, this sentence definitely comes from the heart.
If he uses his current level and combines it with the capabilities of computers in this era, then the design will definitely be possible, but if there is a slight deviation, several corrections will definitely be inevitable.
But being able to get a result of 25.16 in one go when the design point is 25.25, after all, depends on the role of the system.
However, when other people hear this sentence, they naturally think that Chang Haonan means that other people here have also made significant contributions.
So they all said that they were only doing their jobs under the leadership of Mr. Chang, and they did not dare to take advantage of others.
This misunderstanding did no harm to Chang Haonan, and it was impossible for him to explain it. He just smiled and moved the topic to another place:
"The testing of the remaining few components needs to be accelerated, especially the combustion chamber and turbine. These two hot-end core subsystems, together with the high-pressure compressor, basically determine the key core performance characteristics of the engine."< br>
“With the performance characteristics, especially the air intake characteristics, I can optimize the design of the aircraft based on the properties of the engine.”
“The design of the aircraft? Hearing that Chang Haonan suddenly mentioned the outflow of the aircraft, that is, the aerodynamic design part, Haiyide was stunned, and he couldn't follow the train of thought:
"You mean..." ”
"In the past, our aero engines were completely or partially imitated, and many of the performance parameters were not decided by ourselves."
Chang Haonan put the test results back on the table next to him and turned around. Walking out, he said:
“In addition, the design level and manufacturing level are not very good, which means that the specific performance of the built engine may be unknown before it is installed.”
"So when it comes to engine-transformer matching, we mainly focus on broadening the adaptability range of the intake duct, so as to match the engine performance indicators that we don't know the results of the lottery as much as possible."
Hear here , including Haiyide, several people showed some embarrassed expressions or actions.
After all, the problems Chang Haonan mentioned do exist.
The long-term "heart disease" in the field of aviation power has indeed put a lot of strength on the overall design department.
Although it is true that some engine models were discontinued due to the cancellation of the aircraft project, in fact, the reverse situation is more common, that is, the aircraft models died due to insufficient engine quality.
It is a yes if you train with weights.
Of course, Chang Haonan obviously did not want to emphasize these, so after a brief pause, he immediately changed the subject;
"However, now that we have the first engine model that is completely independently developed and has independent intellectual property rights, we can go towards improving the matching accuracy at the level of aircraft engine-transformer matching."
< br>“This is also something that I and the 611 Institute have long determined.”
What Chang Haonan said is naturally the J-10 that needs to replace the DSI air inlet and make overall improvements to the aerodynamic design. Second stage prototype——
Although the turbofan 10 has two main installation targets, the J-11’s adjustable inlet has an extremely wide range of application. As a heavy fighter, it is not inferior to the two to three hundred kilograms. Weight, so there is no need to put too much effort into matching the hair changes.
"That's right..."
After hearing Chang Haonan's answer, Haiyide patted his head gently:
"After this period of time, I almost forgot that Mr. Chang was originally engaged in aircraft design..."< br>
"So what do you mean, the current design of Project No. 10 still needs to be changed?"
The people following Chang Haonan right now are all people in the field of aviation design, although they have not yet They are separated, but after all, there is a layer of relationship between them and several general offices.
In particular, the location of the 611 Institute is more than 2,000 kilometers away in Chengdu.
Therefore, it is normal that they are not very clear about Chang Haonan's plan for the J-10.
“Of course.”
Chang Haonan immediately responded in the affirmative, and then asked:
“The new model that Guizhou Airlines first flew last year, JJ 9, you should know, right?”
Hai Yide nodded:
"Of course I know this. The head office issued a special topic at the end of last year to introduce their advanced examples of using this model to overcome difficult stages and achieve profitability."
"I am going to give Jian 10 Replacing it with a DSI air inlet like that of the JJ-9 can reduce some weight, which is very helpful for the performance of the aircraft.”
Everyone is from the aviation system, and the confidentiality level is high enough. There's nothing to hide.
As a fighter jet, the flight conditions the J-10 has to face are far more complex than those of the J-9, so the requirements for the design of the inlet will also be higher.
People’s general impression is that “DSI inlets are not good at high-speed flight”.
In fact, this is a complete misunderstanding.
DSI air intake only has a narrow optimization range.
A typical example is the scramjets on many hypersonic weapons, which also use DSI inlets.
However, there are still a few hundred million differences between missiles and aircraft.
The former can rely on boosters to get through this stage of low intake efficiency.
But for ordinary aircraft, it may not be needed in high-speed conditions, but it can always be used in low-speed conditions, so there is no option to "optimize only high speeds but not low speeds".
But having said that, if the adaptability range of the inlet is wide enough, then it is not impossible to expand the advantageous working range to the transonic range...
(End of this chapter)< br>