Chapter 874 Design Finalization is a New Beginning

Autumn passes and winter comes.

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

The reason why we had to wait for nearly a month was to find the time window for the last test.

Special test for high altitude and cold weather.

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

No model has ever been done before.

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

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

Therefore, only two WS-10 engines need to be tested this time——

When an aircraft engine is in steady-state operation, the internal temperature can reach thousands of degrees. Even the surface will be heated to a very hot level, so there is naturally no need to consider the low temperature problem.

But the transient process from stopping to starting is not possible.

In particular, many materials will change their properties under extremely cold conditions.

Typically, almost all metals are cold brittle, with strength increasing but toughness decreasing.

Whether aircraft engines with complex structures and huge changes in operating conditions can withstand such abnormal changes is what the high-altitude and cold-weather special test aims to determine.

In addition, this test will also pave the way for the introduction of similar tests in subsequent national standards related to complete machines.

……

Meng Province, Hailar, Dongshan Airport.

Chang Haonan wore 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 pulled his left hand out of the mittens, wiped the white frost on his eyelashes caused by his breath, and then looked at the time.

1:40am.

This action, which lasted less than 5 seconds, made Chang Haonan feel a stinging pain like a knife cutting on his exposed skin.

The chief engineer next to him, Hai Yide, studied in Bingcheng for nearly 10 years when he was young, but after all, he is old and his body can't bear it.

Fortunately, there is a base in Hailar that is not permanently occupied by an aviation unit, and some ground crew members were temporarily sent from there to support it, which made the entire testing process run normally.

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

Dongshan Airport's 2600-meter runway is obviously more suitable for serving such a big guy.

"Boss Chang, the temperature has now dropped to -41.5 degrees Celsius, which has reached the test standard!"

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

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

Wei Qiang, deputy station chief, led the team to assist in the test.

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

Even in China's coldest place, a stable temperature of -40 degrees Celsius is not available every day.

To this end, they have been here for nearly a week.

"Then let's get started!"

"Yes!"

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

There are actually very few subjects involved in the special test, only a few items related to cold engine start-up.

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

In fact, if auxiliary facilities such as power supply, gas source, and fuel are prepared in advance, the time taken for the testing process can be further compressed.

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

If it is subsequently confirmed that low temperature does not pose risks to certain steps, then consider the issue of subtraction.

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

Hai Yide, who was standing next to him, stamped his feet violently, and his voice was trembling.

Chang Haonan wanted to deny it, but when he thought about it carefully, it seemed to be true.

Since the first revision of the national military standard for the WP-14, almost every project he has participated in has required the update of relevant industry standards.

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

"There are no roads in this world. When more people walk on it, it becomes a road..."

This is what Lu Xun said...

On the other hand, although the severe cold caused some deformation of the movements, the ground staff 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 on the aircraft's landing gear and both sides of the wings were lit up at the same time.

The pilot's voice came over the radio:

"The equipment is powered on successfully, and the engine self-check system starts working!"

Although the fault fusion diagnosis system developed by Chang Haonan has not yet been installed on the aircraft because the required sensors are too complex, the WS-10 is an engine model with FADEC after all, so it should have no problem completing a self-check in an available state.

About half a minute later, the radio sounded again:

"Self-test successful!"

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

This is also prone to low temperature failure.

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

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

It seems a bit funny...

However, as a result of this, the atmosphere on the scene, which had just been so tense that it was almost frozen, became a little more relaxed.

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

Technicians are also using instruments to synchronously monitor the aircraft's status.

The formal review standards are more stringent and detailed.

So, it wasn't until more than ten minutes later that they gave the same result.

successfully passed!

Next comes the second experimental phase.

Under electrical common drive, the fuel and lubricating oil system supplying the engine is also activated.

Under low temperature conditions, the flow characteristics of the oil, as well as the working conditions of pipelines, pumps and valves will be affected.

In particular, the two low-pressure pumps and low-pressure shut-off valves installed before the fuel heater are the top priority of low-temperature testing.

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

But in the end, everything turned out just as he expected:

"Oil temperature, oil pressure, fuel flow are normal, and throttle status response is normal!"

Judging from the timing results, although the reaction is slower than normal, it is still within the standard allowable range.

As for the ground start-up process, it doesn't need to be very sensitive, as long as it can faithfully execute the pilot's action intentions.

……

As time went by, the preparations were completed one by one.

Finally, it was time to make the final decision.

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

The temperature has dropped to -43.2c.

God is good.

If the temperature suddenly rises in the middle of the journey, we may have to wait for another time window.

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

"Engine start!"

Almost everyone clenched their fists at this moment.

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

Unseen by anyone, 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.

Almost at the same time, the spark from the electric ignition device ignited everything.

"boom--"

A crisp and short explosion sounded.

Then, there was a slightly sharp roar...

The whole process lasts only one or two seconds, but due to the combined effects of tension and low temperature, it feels like a century or two.

Then, the engine speed suddenly climbed up, then fluctuated slightly a few times, and finally stabilized near the slow speed.

After the engine enters operating mode, the temperature of the entire system will rise to the normal design level.

For special experiments in high-altitude and cold weather, it is no longer a part that requires special attention.

A little 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:

"Engine started successfully!"

At this moment, even the severe cold of minus 40 degrees Celsius could not stop the passion of the participants.

Although there are still some purely administrative procedures to go through before the strict "design finalization", at this point, it is completely possible to open the champagne.

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

"Successful, successful..."

Hai Yide did not make any exaggerated movements. He just clenched his fists, half squatted, and kept muttering.

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

A warm current surged through my body, and in a trance it even seemed to dispel the severe coldness around me.

After a while, several deputy chief engineers including Liu Yongquan and Yin Yongze came over and hugged or shook hands with Chang Haonan and Hai Yide respectively.

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

"Boss Chang, it's done!"

Then the project team members and the appraisal team leader came over and shook hands with Chang Haonan:

"The WS-10 is the first aircraft engine model in China to independently complete 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 was naturally delighted, but as the pillar of the entire project team, he knew that in such a time of jubilation, he should not be too impatient:

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

"The tasks of increasing production capacity and finalizing production still require close cooperation between us!"

The head of the appraisal team was from the Air Force and was so happy that he couldn't stop smiling:

"One by one, one by one... It is an absolute miracle that we can reach this point in three and a half years..."

Production finalization and design finalization are two tasks that sound similar but are performed completely differently.

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

Finally, the entire life cycle was achieved through "small-batch trial production" to achieve large-scale equipment.

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

Chang Haonan just nodded and didn't 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 before we can conduct the verification...