Chapter 596: Matching of engines between turbofan 10 and J-10

Naturally, Europeans, especially Southern Europeans, cannot have high expectations for their work efficiency.

Although for Pierre, the leader, 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 his other technical staff share less of this sense of urgency.

After all, even if the sky falls, there will be someone higher up, 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?

Moreover, on the other hand, Wang Xibo flew thousands of miles from Ice City to Marseille not just 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 NH90's fly-by-wire flight control technology.

Helping Pierre and the others digest and absorb the design plan brought by China can only be regarded as 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 went smoothly, it was still a key node in the project, and it was not easy for him, the chief designer, to be the 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's simply..."

"It's simply a divine calculation..."

A dozen core members responsible for the overall design of turbofan 10 and the compressor section were standing in front of the compressor test bench, looking at the report that had just been compiled by the operator.

Haiyide 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 still 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.

In the previous theoretical calculation and design stage, 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 in one go.

But I have 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 unflattering praise, Chang Haonan turned his eyes from the report in his hand to the compressor on the test stand and answered.

In fact, this sentence definitely comes from the heart.

If he takes 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.

And when the design point is 25.25, the result of 25.16 can be obtained in one go. After all, it still relies 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 just doing their jobs under the leadership of Mr. Chang and 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 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."

“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 Chang Haonan suddenly turn to mentioning 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, turned around and walked out and said:

"In addition, the design level and manufacturing level are not good enough, 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 unknown engine performance indicators as much as possible."

Hearing this, several people, including Haiyide, 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 level.

Weight training is a yes.

Of course, Chang Haonan obviously didn't want to emphasize this, 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."

"This is something that I and the 611 Institute have already agreed on."

What Chang Haonan is talking about is naturally the second phase prototype of the J-10 that will replace the DSI air inlet and make overall improvements to the aerodynamic design——

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-duty fighter, it weighs two to three hundred kilograms, so there is no need to worry too much about engine-transformer matching. effort.

"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..."

"Then you mean that the current design of Project No. 10 still needs to be changed?"

The people who are following Chang Haonan right now are all people in the field of aerospace design. Although they haven't separated yet, they still have a layer of relationship with several general offices.

Especially the location of the 611 Institute is more than 2000 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:

"You should know about the new model of Guizhou Airlines that first flew last year, the JJ-9, right?"

Haiyide nodded:

"Of course we know this. The head office issued a special feature at the end of last year to introduce their advanced examples of using this model to overcome difficult stages and achieve a turnaround from losses to profits."

"I plan to replace the J-10 with a DSI air inlet like the J-9, which can reduce some weight and is very helpful for the performance of the aircraft."

Everyone is from the aviation system, and the confidentiality authority is high enough, so there is nothing to hide in this matter.

As a fighter jet, the J-10 has to face far more complex flight conditions than the J-9, so the requirements for the air inlet design will be higher.

People's general impression is that "DSI inlets are not good at high-speed flight."

In fact, this is a complete misunderstanding.

The 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 hundreds of millions of 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...