Chapter 874 Design Finalization Is a New Beginning

Autumn goes and winter comes.

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

The reason why the team waited for nearly a month was to find the time window for the last test -

High-cold special test.

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

No model has ever been tested 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 test of the Arctic Circle.

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

In the steady-state working state, the internal temperature of the aircraft engine is as high as thousands of degrees, and even the surface will be heated to a very hot degree, so there is no need to consider the low temperature problem.

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

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

Typically, almost all metals have cold brittleness, increasing strength but decreasing toughness.

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

In addition, this test will also pave the way for the introduction of similar tests in the national standards related to the whole machine in the future.

…

Inner Mongolia, Hailar, Dongshan Airport.

Chang Haonan wore the thickest cotton-padded jacket he had ever worn in his life, and wrapped two layers of scarves around him, 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 condensed by his breath, and then took a look at the time.

1:40 in the morning.

This action, which lasted less than 5 seconds, had already made Chang Haonan's exposed skin feel a stinging pain like a knife.

The chief engineer next to him, Hai Yide, went to school in Bingcheng for nearly 10 years when he was young, but after all, his age was here, and his body couldn't stand it.

Fortunately, there is a station in Hailar that is not permanently occupied by an aviation unit, and some ground crew members were temporarily supported from there, which allowed the entire test process to operate normally.

In fact, military aircraft testing is more suitable for military airports, but the local area does not have the hardware conditions to maintain third-generation fighters, so this time, an Il-76 carrying equipment came with the J-11WS.

The 2,600-meter runway at Dongshan Airport is obviously more suitable for serving such a big guy.

"Mr. Chang, the temperature has dropped to minus 41.5℃, which meets the test standards!"

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

All comrades in the Air Force wore uniformly distributed cold-proof masks, so Chang Haonan recognized the identity of the other person by looking at his rank.

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

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

Even in China's coldest place, it is not every day to wait for a stable -40℃.

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

"Let's get started!"

"Yes!"

Wei Qiang stood at attention and saluted Chang Haonan.

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

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 fuel are prepared in advance, the time used for the test process can be further compressed.

But this is the first time that the whole of China has conducted a test under similar conditions, so every link and every detail must be tested perfectly.

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

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

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

Chang Haonan wanted to deny it, but after thinking about it carefully, it seemed to be true.

Since the first revision of the national military standard for the turbojet 14, every project he has participated in has basically had to update the relevant industry standards.

So he had to quote from classics:

"There is no road in this world, but when more people walk, it becomes a road..."

This is really what Lu Xun said...

On the other side, 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 taxiing lights, navigation lights, wing lights and red anti-collision lights on both sides of the aircraft's landing gear and wings were lit at the same time.

The pilot's voice came from the radio:

"The equipment was powered on successfully, and the engine self-test system started working!"

Although the fault fusion diagnosis system developed by Chang Haonan has not been put on the aircraft because the required sensors are too complicated, the WS-10 is an engine model with FADEC after all, so it is no problem to complete a self-test 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 a completely normal state, it at least means that the relevant electronic control unit is in an available 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 are too thick, he didn't show the usual excitement at all.

It looks a bit funny...

However, after this, the atmosphere on the scene, which was almost frozen, was slightly relaxed.

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

The technicians are also using instruments to monitor the status of the aircraft simultaneously.

The formal certification standards are more stringent and detailed.

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

Passed successfully!

Then, it was the second test link.

Under the joint electrical drive, the fuel and lubricating oil system that supplies the engine was also started.

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

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

Perhaps it was Chang Haonan's illusion that 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, fuel flow are normal, and throttle status response is normal!"

From the timing results, although the response is slower than normal, it is still within the standard allowable range-

The ground start process does not need to be very sensitive, as long as the pilot's action intention can be faithfully executed.

...

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

Finally, it is time to make the final decision.

Before the sun rises, the darkest and coldest time of the day.

The temperature has dropped to -43.2℃.

The weather is good.

If the temperature suddenly rises in the middle of the journey, it may take another time window.

Chang Haonan took a step forward and picked up the radio receiver.

"Engine start!"

Almost everyone clenched their fists at this moment.

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

In a place that no one could see, the fuel nozzle began to inject atomized aviation kerosene into the combustion chamber. The fuel quickly and evenly filled the entire space and was fully mixed with the air sent into the combustion chamber through the compressor.

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

"Bang——"

A crisp and short explosion sounded.

Then, there was a slightly sharp roar...

The whole process lasted only about one or two seconds, but under the combined effects of tension and low temperature, it seemed as long as one or two centuries.

Then, the engine speed rose sharply, then fluctuated slightly a few times, and finally stabilized near the slow speed.

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

For the high-cold special test, it is no longer a part that needs special attention.

A little further away, the leader 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 could no longer stop the passion of the test participants.

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

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

"Success, success..."

Hai Yide did not make any exaggerated movements, but just clenched his fists tightly, half-crouched down, and kept muttering.

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

A warm current surged from the body, and in a trance it even seemed to dispel the severe cold around the body.

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

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

"Mr. Chang, it's done!"

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

"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 happy, but as the pillar of the entire project team, he Knowing that in such a time of jubilation, I should not be too impatient:

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

"The subsequent capacity ramp-up and production finalization tasks still require close cooperation between us!"

The leader of the appraisal team, who came from the Air Force, was so happy at this time:

"One by one, one by one... It is an absolute miracle to have come 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 made for a long time, and may even be about to be retired, but the production finalization process has not yet been completed.

In the end, the entire life cycle was achieved 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 had some new ideas on how to improve the production efficiency of air film holes.

Next, he only needed to wait until the equipment of the Torch Laboratory was in place before he could conduct the verification...