The Military-industrial Scientific Research System of the Academic Master Chapter 874

Chapter 874 Design finalization is a new beginning

Autumn passes and winter comes.

In fact, the penultimate project in the entire national identification process was completed in November.

The reason why we waited for nearly an extra month with a large team of people was to find the time window for the last test—

Special test for high cold.

This is a content that has just been added to the final test standards as the China Airlines standards are gradually improved.

No model has ever been carried out before.

The good news is that the J-11WS verification aircraft uses the Su-27UBK airframe.

As a model designed and produced by the Soviet Union, the aircraft itself has experienced the severe cold test of the Arctic Circle.

So, there are only two turbofan 10 engines that need to be tested this time—

Under steady-state working conditions, the internal temperature of the aircraft engine reaches thousands of degrees, and even the surface will be heated to a very hot level. Naturally, there is no need to consider low temperature issues.

However, the transient process from stop to start does not work.

Especially many materials will undergo property changes under extremely cold conditions.

Typically, almost all metals are cold brittle, with increased strength but decreased toughness.

Whether an aero engine with a complex structure and huge changes in operating conditions can withstand such abnormal changes is what the special high-cold test will determine.

In addition, this test will also pave the way for the subsequent introduction of similar tests into national standards related to the entire machine.

Hailar, Dongshan Airport, Meng Province.

Chang Haonan was wearing the thickest cotton-padded coat he had ever worn in his life, and two layers of scarves, but he was still shivering in the cold wind.

He took his left hand out of his mittens, wiped the white frost on his eyelashes, and then looked at the time.

1:40 am.

Just such an action, which lasted less than 5 seconds, already made Chang Haonan feel a knife-like sting on his exposed skin.

The chief engineer next to him, Hai Yide, went to school in Bingcheng for nearly 10 years when he was young, but after all, despite his age, his body was a little unable to bear it.

Fortunately, there is a local station in Hailar where aviation units are not permanently stationed. From there, some ground crews were temporarily supported, which allowed the entire testing process to run normally.

In fact, originally, military aircraft testing was more suitable to be carried out at military airports, but the local area did not have the hardware conditions to maintain third-generation fighter jets, so this time there was an Il-76 carrying equipment following the J-11WS.

The 2,600-meter runway of Dongshan Airport is obviously more suitable for serving such big guys.

“Mr. Chang, the temperature has now dropped to minus 41.5℃, which has reached the test standard!”

Just when Chang Haonan was wondering whether to let Hai Yide go inside the terminal to warm up, a man suddenly strode up to Chang Haonan and reported loudly.

All comrades in the Air Force wore uniformly issued cold masks, so Chang Haonan recognized the person's identity after looking at the other person's military rank.

The deputy director of the site who led the team to assist in the test, Wei Qiang.

Chang Haonan took a deep breath, and a long wisp of white mist emerged from his mouth and nose.

Even in the cold pole of China, waiting for a stable -40℃ does not happen every day.

For this reason, they have been staying here for nearly a week.

“Then let's get started!”

"yes!"

Wei Qiang stood at attention and raised his hand to salute Chang Haonan.

The special test involves very few subjects, only a few related to engine cold start.

As Chang Haonan's order was issued, the vehicles and personnel who had been waiting for several days around the fighter plane suddenly became busy.

In fact, if auxiliary facilities such as power supply, gas source, and oil are prepared in advance, the time spent in the test process can be further reduced.

But after all, this is the first time that the test has been conducted under similar conditions in China, so every link and every detail must be tested thoroughly.

If it is later confirmed that low temperature does not pose a risk to certain steps, then consider subtraction.

“I always feel like every time I do a test with you, I can see some new tricks that I haven't seen before.”

Hayide next to him stamped his feet violently, his voice trembling a little as he spoke.

Chang Haonan wanted to deny it at first, but when he thought about it carefully, it seemed that this was really the case.

Since the first revision of the national military standard for the Turbojet 14, every project he has participated in has basically updated the relevant industry standards.

So I had to come up with a wave of quotations from scriptures:

“There is no road in this world, but when there are more people walking on it, it becomes a road…”

This is really what Lu Xun said...

On the other side, although the severe cold caused some deformation of the movement, the ground crew and technicians still connected the pipelines of several auxiliary vehicles to the aircraft within the time specified in the outline.

With a sharp buzzing sound, the taxi lights, navigation lights, wing lights and red anti-collision lights located on both sides of the aircraft's landing gear and wings were illuminated at the same time.

The voice of the pilot in the cockpit came over the radio:

“The equipment is powered on successfully and the engine self-checking system starts working!”

Although the fault fusion diagnosis system developed by Chang Haonan has not yet been put on an aircraft because the sensors required are too complex, the Turbofan 10 is an engine model with FADEC after all, so it is no problem to complete a usable status self-check.

About half a minute later, the radio rang again:

“Self-test successful!”

Although passing the self-test does not 100% mean that the engine status is completely normal, it at least indicates that the relevant electronic control unit is in a usable state.

This is also prone to low temperature failure.

Beside Chang Haonan, someone excitedly waved his fist in the air.

It's just that because the clothes were too thick, I didn't show the usual excitement at all.

Instead, it seems a bit funny...

However, after being disturbed in this way, the atmosphere at the scene, which had just been so serious that it was almost frozen, became slightly more relaxed.

Of course, the national certification test is definitely not a success just because the pilot says it is a success.

Technicians are also using instruments to simultaneously monitor the status of the aircraft. Formal accreditation standards should be more stringent and detailed.

So, it was not until ten minutes later that they gave the same result.

successfully passed!

Immediately afterwards, there is the second test session.

Under the joint electric drive, the fuel oil system supplying the engine is also activated.

At low temperatures, the flow characteristics of oil and the working conditions of pipelines, pumps and valves will be affected.

Especially the two low-pressure pumps and the low-pressure shut-off valve set before the fuel heater are the top priority for low-temperature testing.

Perhaps it was Chang Haonan's illusion, but the time interval between the pilot's results was much longer this time.

But in the end, everything was as he expected:

“Oil temperature, oil pressure, and fuel flow are normal, and the throttle status response is normal!”

Judging from the timing results, although the response is slower than normal, it is still within the allowable range of the standard—

As for the ground startup process, it doesn't need to be very sensitive, as long as it can faithfully execute the pilot's intention.

As time goes by, the preparations are completed one after another.

Finally, the final moment has come.

The darkest and coldest time of the day before the sun rises.

The temperature has dropped to -43.2℃.

God is doing his best.

If the temperature suddenly rises midway, you may have to wait for another time window.

Chang Haonan took a step forward and picked up the wireless phone.

“Engine start!”

Nearly everyone clenched their fists at this moment.

As long as this step is completed, the turbofan 10 will officially complete the design finalization appraisal.

In a place where everyone cannot see it, the fuel nozzle begins to inject atomized aviation kerosene into the combustion chamber. The fuel quickly and evenly fills the entire space and is fully mixed with the air sent into the combustion chamber through the compressor.

At almost the same time, the electric spark generated by the electric lighter ignited it all.

"boom-"

A crisp and short blast sounded.

Following that, there was a slightly sharp roar...

The entire process lasted only about a second or two, but under the combined effect of tension and low temperature, it seemed as long as a century or two.

Subsequently, the engine speed climbed sharply, then fluctuated slightly, and finally stabilized near the idle speed.

After the engine enters the working state, the temperature of the entire system will also rise to the normal design level.

For special alpine experiments, it is no longer a part that requires special attention.

Slightly further away, the head of the appraisal team of the General Armament Department took off his headphones, stood up and looked at Chang Haonan and his group:

“The engine started successfully!”

At this moment, even the severe cold of minus 40 degrees Celsius could no longer stop the enthusiasm of the test participants.

Although there are still some purely administrative processes to go before the strict "design finalization", at this point, the champagne can be opened.

Some people even took off their cotton hats and threw them into the air in ecstasy.

“Successful, successful…”

Hayide didn't make any exaggerated movements, he just clenched his fists tightly, squatted down, and kept mumbling.

Hearing his voice, Chang Haonan finally breathed a sigh of relief.

A warm current surged from his body, and for a moment it even seemed to dispel the severe cold all over him.

After a while, several deputy chief divisions, including Liu Yongquan and Yin Yongze, came closer from the surroundings and hugged or shook hands with Chang Haonan and Hai Yide respectively.

Chang Haonan couldn't even tell whether what was hanging around some people's eyes was frost from breath or frozen tears...

“Mr. Chang, it's done!”

Following the members of the project team, the leader of the appraisal team also came over and held Chang Haonan's hands tightly:

“The Turbofan 10 is China's first aircraft engine model that has independently completed the entire process from project establishment to finalization. I am honored to have the opportunity to personally participate in it.”

“It's not time to relax yet.”

Chang Haonan is naturally happy in his heart, but as the anchor of the entire project team, he knows that he cannot be too impatient during such a time of joy:

“Design finalization is both the end of the previous stage and the beginning of a new stage.”

“The subsequent tasks of ramping up production capacity and finalizing production will require close cooperation between us!”

The leader of the appraisal team was born in the Air Force, and he was already grinning from ear to ear:

“One item at a time, one item at a time… It's an absolute miracle that we can get to this point in three and a half years…”

Production finalization and design finalization are two tasks that sound similar but are completely different in practice.

Some equipment may have been manufactured for a long time, and may even be almost retired, and the production and finalization process has not yet been completed.

In the end, the entire life cycle was implemented as a "small batch trial production" to achieve large-scale equipment.

So, he knew that this matter could not be rushed.

Chang Haonan just nodded and did not reply.

But in fact, he already has some new ideas on how to improve the production efficiency of air film holes.

Next, we just need to wait until the equipment in the Torch Laboratory is in place, and then we can conduct verification...

(End of this chapter)

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