The test engineers present looked at the door in unison.

"Precursor?"

One of them gently pushed the glasses on the bridge of his nose.

Now Chang Haonan's name is also well-known in the industry, so he hesitated a little at first.

But after making sure that there was no obvious abnormality in the curve displayed on the computer screen, I decided to show the spirit of not fearing authority:

"But everything is working fine with the data we've just collected...... Didn't you see any problems? ”

"Yes, if the working curve is not normal, you should be able to see the fluctuation from the working Reynolds number and the flow rate of the compressor......"

In the end, it was Xue Chiyu who made the final decision:

"Anyway, stop the engine first!"

Even if the engine runs in a slow state, after all, it is still in a high-temperature and high-pressure working state, and if there is a real problem, the consequences are still relatively serious.

"Yes!"

The chief engineer who was able to finally make the decision spoke, and the atmosphere in the control room that had just been a little overwhelmed finally dissipated a little.

The roar in the test room gradually subsided, and finally calmed down.

A group of people looked solemnly at the fighter plane in the test workshop that glowed with metallic luster in the light.

"Export the data and let Chang Gong and Yang Gong take someone to analyze the situation first."

After a few seconds of silence, Song Wencong was the first to speak.

Only Chang Haonan and Yang Wei participated in the development of this active stability system, and this matter naturally had to be completed by them.

"Old Xue, old Song."

At this time, another man wearing a long-sleeved shirt and looking a little sickly:

"Do you want to drive again? After all, the comrades at the test flight station were right, we didn't observe any signs of malfunction just now. ”

Chang Haonan thought briefly in his memory, and then confirmed that he had no impression of this face.

But to be able to call the chief engineer and chief engineer in such a casual way obviously should not be ordinary people.

However, Xue Chiyu's first reaction after turning around and seeing the person coming was surprise, and then he hurriedly walked up:

"Old Yang? Why did you run back from the hospital again? ”

The person who came waved his hand to show that it was okay:

"Didn't I hear that you have started ground testing, how much better my body can be even if I stay in the hospital, why don't you come and see."

Xue Chiyu sighed when he heard this, opened his mouth, but didn't say anything in the end.

After a while, he turned sideways again, stretched out his palm and gestured in the direction of Chang Haonan and introduced:

"Old Yang, this is ......"

"I know, Comrade Chang Haonan, I've heard about it in the hospital."

The man cheered up, walked up to Chang Haonan and looked at him a few times, then stretched out his hand:

"My name is Yang Baoshu, Comrade Xiaochang, a young talent, it's better to see it than to hear it."

This name made the latter suddenly realize, and then he felt a little sour in the corners of his eyes-

Yang Baoshu, general manager of Rong Fei, was diagnosed with advanced lung cancer in 1995, but he still insisted on working with illness and died in 1999 in the original timeline.

"Hello, Mr. Baoshu."

On this occasion, Chang Haonan didn't want to say anything else, so he had to stretch out his hands and shake the other party's hands tightly.

"Xiao Chang, I have just asked the engineer on site to understand the situation, and I don't mean anything about you personally, but if no obvious signs of failure are observed, can you repeat the test again?"

After getting to know each other, Yang Baoshu quickly returned to the topic,

"If the problem can be repeated, it's not too late for us to terminate the test and take it apart for inspection."

If it is reasonable, Yang Baoshu's suggestion is actually no problem.

Fault identification, in fact, it is difficult to say who is right and who is wrong, and the recurrence of the problem is indeed a part of the problem, after all, the probability of the problem of the sensor or algorithm itself is not small, and a test alone cannot explain too many problems.

But Chang Haonan has read the script, and he knows that this engine did have problems in the test in the previous life.

And now that his active stability control system has called the police, he certainly can't continue to take risks.

Maybe the next time it reaches 40% or 50%, it will be a real problem.

Surge prediction can only predict the surge gradually caused by normal air intake distortion, if the plane suddenly hits a bird or sucks in a large foreign body, the gods will not be able to save it.

"Don't worry about Mr. Baoshu, we haven't reached the step of dismantling the plane yet."

Chang Haonan can only choose to stabilize the other party first,

"The current test system integrates the latest technology developed by me, which can predict the upcoming surge or rotational stall through a small amplitude disturbance wave with certain characteristics, and the comrades of the test flight station will take the data, I can analyze it on the spot, if you can find the hidden danger, you can carry out targeted troubleshooting or improvement, if you can't find it, then restart the test run, and it won't take too long."

Hearing that there was no need for large-scale rework, Yang Baoshu finally breathed a sigh of relief and did not raise any objections.

About half an hour later, a staff member of the test station walked out of the test control room with a laptop.

"Chang Gong, the test data just now is in it."

Chang Haonan took the computer and connected the power supply to the socket next to it.

Everyone in the room came up behind him with the fastest movements, forming a semicircle that could not be penetrated.

In the end, it was a few people in the inner circle who consciously squatted down so that everyone could see the small screen.

All here are experts in the field of aeronautical engineering.

Whether they believe Chang Haonan's statement or not, everyone wants to see what this surge aura is all about.

After several rounds of data processing inside the software, there are now only a few curves left.

Insiders can see that Chang Haonan's operation just now is to separate the components of the measured signal at a specific frequency.

"Look here."

Chang Haonan pointed to one of the curves and said,

"The component of the modal wave of the engine operating curve on the surge characteristic frequency, which is absent at first, suddenly appears at 540 seconds of the test, and then gradually increases, and at the 580th second, it is monitored by the surge prediction system, and then the throttle valve opening is forcibly retracted, and after 20 seconds, this component disappears again."

"This ......"

Of course, everyone can understand a curve, but there are still many people who don't understand why this curve is related to surge.

At this time, Yang Wei, who was also involved in the whole process of software development, turned around and briefly introduced the basic working principle of this system to other colleagues.

"Let me explain that when the engine is far away from the surge boundary, the system has a strong attenuation effect on small random disturbances inside the system, and at this time, even if there is some interference, it will be quickly erased and will not continue to deteriorate. With the decrease of the stability margin of the engine, the damping of the system to the small random disturbance also decreases gradually, and when the stability margin decreases to a certain extent, the small random disturbance inside the system will occur as the initial disturbance of the mode wave with a relatively stable frequency......"

"...... from 580 seconds"

Someone noticed the timestamp that Chang Haonan had just mentioned, so he compared it with the test log recorded by another computer, and then shouted in surprise:

"Wait, Commander Zhou gave 70% of the password at 570 seconds, that is to say, at 540 seconds, when Chang Gong's analysis began to be abnormal, the throttle valve should still stay at 60%!"

As soon as these words came out, the surrounding crowd erupted into a burst of discussion again.

Obviously, it is not the action of pushing the throttle valve to 70% that induces the surge premonitor, but the hidden danger at an earlier stage.

Or maybe there is a problem with the surge prediction logic of this set of active stability control.

On the one hand, although Chang Haonan now has a certain degree of popularity, most of the people on the scene have not worked with him before, and their ears are empty after all.

On the other hand, the basic principles just introduced by Yang Wei are indeed quite complex in mathematics, and most people can only understand them, and it is naturally difficult to agree from the bottom of their hearts when their understanding is not thorough enough.

Fortunately, Xue Chiyu and Song Wencong and other main persons in charge had a deeper understanding of Chang Haonan, and after a brief discussion, they still ordered the suspension of this start-up test.

The Chinese people pay attention to a good start, and the first start of the trial ended in a hurry, although many people present obeyed the order, but their emotions were still affected.

At this time, a loud voice sounded from the outermost part of the crowd:

"Well, there's no need to overhaul the plane first, I can drill into the air intake and see what happens to the fan and the low-pressure compressor blades!"

(End of chapter)